Heart Attack

What Is A Heart Attack?

The term “heart attack” is often used to refer to signs and symptoms that result from the sudden blockage of blood flow to a portion of the heart. Without good blood flow, the heart does not receive enough oxygen and begins to die.

People suffering a heart attack may experience symptoms such as chest pain, sweating, nausea, weakness, and shortness of breath. Each year about 1.5 million Americans have heart attacks. Heart disease remains the leading cause of death in the United States for both men and women.

Heart attack is the common term for a “myocardial infarction.” This refers to the permanent damage done to the heart muscle, or myocardium, when blood flow is blocked. A heart attack most commonly happens when a blood vessel that brings blood to the heart is suddenly blocked by a blood clot.

While heart attacks usually come on suddenly, it’s really the result of a process that takes years to develop. Over time, a person’s blood vessels may become hardened and narrowed by the buildup of cholesterol and other fatty substances. Reducing risk factors for coronary artery disease – such as high cholesterol or high blood pressure – is an important way to prevent a first or subsequent heart attack.

A heart attack usually occurs over several hours. Fast action is the best weapon against a heart attack. If a person is treated during the first two hours after a heart attack, early treatments can improve outcomes.

For example, medications called “clot busters” can break down a blood clot blocking a coronary artery, restoring blood flow to the heart and even preventing or reducing the amount of permanent damage done to the heart. In addition, preventing or treating serious abnormal heart rhythms that may occur with a heart attack are an important ways of saving lives.

Need To Know:

A heart attack is a serious condition. But early treatment can improve the outcome by reducing the amount of heart muscle that is damaged and decreasing or preventing complications of a heart attack. Minutes count! If you or someone you know suspects a heart attack, get emergency medical help right away.

The coronary arteries supply the heart muscle with oxygen and nutrients. The word “coronary” means a crown, and is the name given to the arteries that circle the heart like a crown.

Coronary artery disease (CAD) is the most common form of heart disease.

Coronary heart disease develops when one or more of the coronary arteries that supply the blood to the heart become narrower than they used to be, due to the buildup of cholesterol and other substances in the wall of the artery, affecting the blood flow to the heart muscle. Without an adequate blood supply, heart muscle tissue can be damaged.

Deposits of cholesterol and other fat-like substances can build up in the inner lining of these blood vessels and become coated with scar tissue, forming a cholesterol-rich bump in the blood vessel wall known as plaque. Plaque buildup narrows and hardens the blood vessel, a process called atherosclerosis, or hardening of the arteries.

Eventually these plaque deposits can build up to significantly reduce or block blood flow to the heart. A person may experience chest pain or discomfort from inadequate blood flow to the heart, especially during exercise when the heart needs more oxygen. This type of chest pain is called angina.

Angina is the body’s warning sign that the heart is being overworked. It can be experienced in a variety of ways.

  • Angina usually manifests as a feeling of pain, pressure, or tightness in the middle chest, especially behind the sternum (breastbone).
  • The sensation may spread to the left shoulder, arm, and hand, or to the neck, throat, and jaw.
  • The attack typically lasts for only a few minutes

An attack of angina does not cause permanent damage to the heart muscle. This is the main difference between angina and a heart attack, during which part of the heart muscle suffers permanent damage (unless the new clot-busting drugs are given in time).

For more detailed information on angina, go to Angina.

Facts About Heart Attack

  • The adult human heart is about the size of a clenched fist.
  • Hearts have been known to pump for 100 years without resting more that a second at a time – a feat unequaled by any man-made device.
  • The average heart beats 60 times a minute; 3,600 times an hour; 86,400 per day; 31.5 million per year, and 2.4 billion in a lifetime.
  • In an average lifetime, the heart pumps 1 million barrels of blood – enough blood to fill 3.3 supertankers – and expends more than enough energy enough to lift a battleship out of the water.
  • In the U.S., about 26.3 million men (27.6 percent) and 22.7 million women (22.1 percent) are smokers, putting them at increased risk for a heart attack.
  • About 99.5 million American adults have total blood cholesterol values of 200 mg/dL and higher (borderline high). About 39.9 million American adults have total blood cholesterol levels of 240 or above (high). An elevated blood cholesterol level is a risk factor for a heart attack.
  • As many as 50 million Americans have high blood pressure, which places them at risk for a heart attack.
  • About every 29 seconds, an American will experience a heart problem.
  • It’s estimated that 7.2 million Americans age 20 and older have a history of a heart attack (4.4 million men and 2.8 million women).
  • Each year, about 1.1 million Americans are expected to have a new or recurrent coronary attack.


Types Of Heart Attack

Depending on which coronary artery is affected, and where it becomes blocked, different parts of the heart are damaged at the time of a heart attack.

The right coronary artery carries blood to

  • the right side of the heart (the right atrium and right ventricle)
  • portions of the left side of the heart
  • parts of the heart that control the heart rhythm

The left coronary artery splits into the left anterior descending artery (LAD) and the left circumflex artery, supplying blood mostly to:

  • the left side of the heart (left atruim and left ventricle)
  • the wall of muscle that divides the right and left sides of the heart

Most heart attacks are caused by a plaque rupture and blood clot, or coronary thrombus, in a coronary artery. When a plaque ruptures, it sets off a series of events that can result in clots being formed. This happens when clot-promoting substances contained inside the plaque are exposed to the circulating blood.

Need To Know:

The amount of damage caused by a plaque rupture depends on the size of the rupture. If a plaque rupture is minor, a small blood clot may form but might only partially block a coronary artery. Eventually, the clot may become part of the plaque again or get broken down. A large rupture can lead to the formation of a larger clot that can partially or completely block a coronary artery.

Non-Q-wave heart attack: Sometimes, a coronary artery can become partially blocked and the blockage remains in place for a long time. Over time, a lack of blood (and oxygen) can cause unstable angina, as well as a non-Q wave heart attack. This type of attack shows up differently on a electrocardiogram (ECG), one of the tools used to diagnose a heart attack. This type of heart attack usually involves the innermost layer of heart muscle, which is most susceptible to inadequate blood flow.

A non-Q wave heart attack also may occur if a blood vessel is:

  • totally blocked for only a short time
  • totally blocked for a long period of time, but other nearby blood vessels provide some blood flow.

Sometimes, the heart’s blood supply can be blocked totally but for just a short time. Usually a spasm or a clot that dissolves is the cause of such an occurrence.

Q-wave heart attack: If a coronary artery is blocked for a long time and blood flow supplied by smaller surrounding blood vessels is poor, the clot will likely cause a Q-wave heart attack. It gets its name because it is general associated with abnormally deep Q waves on the electrocardiogram (ECG). This type of a heart attack generally involves the death of muscle cells throughout the entire thickness of the heart muscle wall.

Other Causes

In rare cases, other factors severely reduce blood flow to heart muscle, causing a heart attack. These causes should be considered in people who are young or who have few or no risk factors for coronary artery disease. These include:

  • Coronary emboli, in which a piece of a blood clot, a mass of bacteria, or other foreign body in the coronary vessel. These can come from infected or artificial heart valves, blood clots inside the heart’s chambers, and even heart tumors.
  • Blood clots not associated with coronary artery disease, which can be caused by trauma, conditions associated with an increased tendency to form blood clots, or the use of birth control pills in some women.
  • Congenital (existing at birth) abnormalities of the coronaryarteries
  • Severe spasm of the coronary artery, which cause a sudden contraction of muscle in the wall of an artery. This can cause a temporary blockage to all layers of heart muscle, resulting in a Q-wave heart attack.
  • Conditions that increase the “stickiness” or thickness of a person’s blood
  • Marked increase in the oxygen demand of heart muscle, such as aortic stenosis

Most of these “other causes” of a heart attack restrict blood flow to heart muscle by blocking or narrowing a coronary artery. The exception is an increase in the “stickiness” of blood, which causes reduces blood flow to heart muscle because blood cells have difficulty sliding past one another.

Need To Know:

Coronary spasm

Coronary spasm can cause a heart attack. Spasm of unknown cause are called primary or idiopathic coronary spasm. Causes of secondary coronary spasm include cocaine or amphetamine abuse.

In addition to causing a heart attack, coronary spasm can also cause variant orPrinzmetal’s angina. This unusual type of angina occurs at rest or during sleep and is usually associated with coronary artery disease. People with variant angina are at increased risk for serious cardiac arrhythmias and sudden death as well as a heart attack.

Nice To Know:

Syndrome X is a rare cause of a heart attack and refers to angina in people with “normal” coronary arteries. They experience angina symptoms but no signs of blood vessel narrowing shows up during acoronary angiography. (During this test, dye is injected into coronary arteries to look for any narrowing.)

However, some patients do show signs of inadequate blood flow to heart muscle (ischemia) during an exercise tolerance or stress test. This may be due to decreased amount of substances that dilate widen blood vessels from the cells that line blood vessel walls.


What Are The Symptoms Of A Heart Attack?

Heart attacks occur most frequently between 6 and 10 a.m. This may be due to

  • Higher amounts of the hormone epinephrine (adrenaline) in blood in early morning
  • An increased systolic blood pressure
  • Increased blood thickness or “stickiness”

Most individuals experience symptoms with a heart attack. In fact, about two-thirds of people experience symptoms beginning in days to weeks before the heart attack, including

  • Vague chest discomfort
  • Fatigue
  • Malaise (a feeling of general discomfort or uneasiness)
  • Shortness of breath
  • Weakness
  • Nausea and/or vomiting

Need To Know:

Silent Heart Attacks

Up to 20 percent of people experience “silent” heart attacks that have no symptoms. These heart attacks are only diagnosed afterward during a routine electrocardiogram (ECG) or if the heart attack causes complications.

Symptoms Or “Warning Signs” Of A Heart Attack

Severe chest pain is the most common symptom of a heart attack. This is described as pressure, fullness, burning, or a squeezing sensation, which lasts for more than a few minutes or goes away and then comes back. This pain usually occurs while the individual is at rest or engaged in only mild physical activity.

Qualitatively, the pain is similar to the pressure, tightness, or burning sensation experienced with stable angina.

Compared with stable angina, chest pain due to a heart attack

  • Is generally more severe
  • Lasts longer (30 to 60 minutes or more compared with 5 to 10 minutes)
  • May spread more widely to sites including the left and/or right arm, back, neck, jaw, teeth, and throat

Unlike stable angina, the pain with a heart attack is not relieved by rest. There may be little or no response to nitroglycerin, a medication that dilates coronary arteries and typically relieves angina.

Other symptoms include:

  • Atypical chest pain or abdominal pain
  • Nausea or vomiting
  • Sweating and paleness
  • Weakness
  • Palpitations, which is an awareness of the heart beating more rapidly, forcefully, or irregularly
  • Restlessness or sense of impending doom
  • Shortness of breath and unexplained difficulty breathing

Need To Know:

Women and heart attacks

Women account for nearly half of all heart attack deaths. Heart disease is the number one killer of both women and men.

As with men, women’s most common heart attack symptom is chest pain or discomfort. But women are somewhat more likely than men to experience some of the other common symptoms, particularly shortness of breath, nausea/vomiting, and back or jaw pain.

Women are less likely than men to believe they’re having a heart attack and more likely to delay in seeking emergency treatment.

Not all of these symptoms occur in every attack and some may occur, go away, and then return.

What To Do If These “Warning Signs” Occur?

A person who experiences one or more signs of a heart attack that last more than several minutes, or that go away and then return, needs immediate medical attention. Call 911 or the emergency medical services. If ambulance services are not available, the individual should be driven to the nearest hospital. The patient should NOT attempt to drive there alone.

It’s common for a person having a heart attack to protest calling for emergency help. Don’t let that stop you from calling an ambulance.

Helpful tips

  • Let the person’s family know where he or she is being taken.
  • Have a family member provide a list of all medications and dosages that patient is taking, including drugs for angina or other heart conditions. Bring the prescription bottles, if possible.
  • Begin cardiopulmonary resuscitation (CPR) if necessary and if the bystander is properly trained.

What Causes These Symptoms?

The pain from a heart attack comes is caused when oxygen-starved heart muscle cells release chemical substances onto nearby nerve endings. This stimulates the body’s nervous system, which triggers other symptoms.

  • Stimulating a portion of the nervous system called the sympathetic nervous system leads to the sweating (diaphoresis), cool and clammy skin, increased heart rate, and palpitations often observed with a heart attack.
  • Stimulation of another portion of the body’s nervous system – the parasympathetic nervous system – causes the weakness, nausea, and vomiting that sometimes accompany a heart attack.
  • Shortness of breath may be caused by a build-up of fluid in lung airways that happens when the pumping action of the heart has been impaired.

Is It A Heart Attack Or Some Other Condition?

It’s sometimes hard to tell if chest pain is caused by a heart attack or another condition. For example, pain related to a heart attack is frequently mistaken for indigestion and can even be briefly and partially relieved with belching or antacids. Conversely, people with pain from gastroesophageal reflux (“heartburn”) frequently mistake their pain for heart pain. Conditions sometimes confused with a heart attack include:

Other heart conditions, such as

  • Pericarditis (inflammation of outer covering of heart)
  • Myocarditis (inflammation of heart muscle)
  • Disease of cardiac valves (flaps of tissue that control blood flow through heart chambers)
  • Acute aortic dissection, or the splitting of the wall of the aorta

Gastrointestinal conditions (conditions affecting the stomach or intestines)

  • Gastroesophageal reflux, the backward flow of stomach contents into the esophagus producing a burning pain often referred to as “heartburn”
  • Esophageal spasm, or a sudden contraction of muscle in wall of esophagus
  • Duodenal or gastric ulcer – ulcers in the stomach or upper portion of intestine
  • Gastritis, an inflammation of the stomach
  • An inflammation of the gallbladder
  • Gallstones
  • Pancreatitis, which is an inflammation of the pancreas

Musculoskeletal disorders (conditions affecting muscle or skeleton)

  • Fractured rib
  • Costochondritis or an inflammation of one or more segments of rib cartilage

Lung conditions

  • Pneumonia, an inflammation of the lungs
  • Pulmonary embolism, a piece of a blood clot in the pulmonary arteries that usually comes from a detached blood clot formed in leg veins
  • Pneumothorax or the presence of air or gas in space that holds the lungs

Need To Know:

Doctors rely on taking a person’s medical history to help distinguish a heart attack from other conditions. Findings on the physical examination and a various diagnostic tests help determine if the pain is caused by underlying heart disease.

It is important for the doctor, not the individual, to decide whether the pain is or is not related to heart disease. Seek immediate medical attention if one of more warning signs of a heart attack occurs for more than several minutes.


What Happens Before And At The Hospital?

Although there is some overlap, care provided to a heart attack patient can be divided into three settings:

  • Prehospital (outside the hospital and in the hospital emergency department)
  • Hospital (inpatient care, including the coronary care unit)
  • Convalescent (recovery and rehabilitation)

Care provided in the prehospital and hospital settings focuses on:

  • Relief of distress, including chest pain and anxiety
  • Limiting the size of the heart attack (i.e., the area of heart muscle that dies)
  • Reducing the work of the heart
  • Preventing and treating complications of a heart attack

Since not everyone who comes to the hospital with chest pain has had a heart attack, it’s important to establish an accurate diagnosis quickly. This is done based on information obtained from the personal health history, physical examination, and diagnostic tests.

In contrast, convalescent care, including cardiac rehabilitation, focuses more on restoring the ability of an individual to function normally, or as close to normally as possible, following a heart attack. This care usually begins during the hospital stay and continues after the person has returned home.

Prehospital And Emergency Department Care

Prehospital care refers to care provided outside the hospital and in a hospital emergency department by early-responder rescuers, such as police, firefighters, and paramedics, as well as emergency personnel. The focus of this care is rapid intervention and may include

  • defibrillation to restore normal heart rhythm
  • thrombolytic drugs to dissolve the blood clot

Because 50 to 60 percent of deaths from a heart attack occur within the first several hours, prompt treatment is essential.

Clot-dissolving (thrombolytic) drugs are used to break up a blood clot in a coronary artery. They can

  • Reduce the size of the heart attack
  • Improve heart function
  • Reduce the risk of death

Although the cause of the chest pain is not always clear, someone with severe chest pain is treated as though they have suffered a heart attack until proven otherwise. More tests are done once the patient reaches the hospital.

At The Hospital

Once at the hospital, the following are begun to help in the rapid assessment of the individual and the provision of early treatment.

  • Placement of an intravenous (IV) line: This involves placing a small tube or catheter into a vein to permit the IV administration of fluids and medications.
  • Beginning continuous electrocardiographic (ECG) monitoring: This permits continuous monitoring of the heart’s electrical system to screen for abnormal heart rhythms called arrhythmias.
  • Obtaining a 12lead electrocardiogram: A 12-lead electrocardiogram (ECG) will also be obtained upon arrival at the emergency room followed by sequential (repeat) ECGs for monitoring and diagnostic purposes.
  • Administration of medication to dilate (widen) arteries, if appropriate: Nitroglycerin can be used to relieve pain and improve blood flow if the blood pressure and heart rate are stable. Nitroglycerin will also relieve coronary artery spasm, which causes four percent of acute heart attacks.
  • Provide adequate pain relief. If pain is not sufficiently relieved with nitroglycerin (or nitroglycerin administration is not appropriate), morphine is used to relieve pain.
  • Administer oxygen through a face mask or nasal tubes.
  • Stabilize blood pressure and heart rhythm: If necessary, intravenous (IV) fluids or medications can be given to prevent or treat abnormal heart rhythms, low blood pressure, or other complications.
  • Draw blood to determine cardiac enzymes: This involves obtaining a blood sample to look for increased levels of certain cardiac enzymes, which indicate the presence of damage to heart muscle.
  • Administer aspirin, if appropriate. Aspirin prevents blood clot formation and should be started in the emergency department and continued indefinitely, barring any contraindications.
  • Evaluate and administer thrombolytic drugs or clot busters, if appropriate. Thrombolytic drugs can break down or lyse a blood clot blocking a coronary artery and allow blood flow to a region of heart muscle to be restored. This can reduce and even prevent muscle damage and improve outcomes.
  • Evaluate for signs of complications from heart attack. Physical examination and diagnostic tests will help detect evidence of any complications.

In addition to the events, the emergency doctor also evaluates the individual to help make a diagnosis and determine appropriate treatment. This involves obtaining a brief personal health history and performing a physical examination.

The patient or a family member is asked about

  • The location of the pain. Where did the pain start? Has it spread to other areas?
  • The character or quality of the pain. Is the pain dull or sharp? Is the pain steady or intermittent?
  • The intensity of the pain. How severe is the pain? How would you rate it on a scale of 1 to 10, with 10 being the most severe pain you have ever experienced?
  • The duration of the pain. How long has the pain lasted?
  • The frequency of the pain. Has the pain occurred before and if so, when and how often?
  • Other factors. What were you doing when the pain started? Does anything make the pain better or worse?

The doctor also asks about:

  • Previous and current health problems
  • Risk factors
  • Past history of heart disease
  • Habits, including use of cigarettes, alcohol, or “recreational” drugs
  • Current medications (prescription drugs, over-the-counter drugs, and herbal remedies)
  • Allergies (especially to medications)
  • Past and current health problems of family members

These questions are directed at identifying specific risk factors for coronary artery disease and help distinguish between a heart attack and some other condition.

Hospital Admission

Not everyone who goes to the emergency room with chest pain is admitted to the hospital. But if there is a reasonable chance that the pain is due to a heart attack or other serious condition, the person is admitted.

Depending on the level of care needed, he or she may go to

  • The coronary care unit (CCU)
  • Another unit with a monitored bed that has the capability for continuous ECG monitoring, often called a “step-down unit.”

The step-down unit is more appropriate for lower-risk patients who may not have had a heart attack. Patients can be transferred between locations as needed.

Heart Attack: Hospital Care And The Coronary Care Unit (CCU)

Most patients suspected of having suffered an acute heart attack are admitted to a hospital’s coronary care unit (CCU). The CCU is intended to be a quiet, calm, and restful area in which patients can be further evaluated and closely monitored. A specially trained nurse who works with doctors and other members of the medical team provides individualized care. Visiting hours are usually restricted.

The length of stay in the CCU varies, depending on :

  • Whether or not the diagnosis of a heart attack is confirmed
  • The severity of the heart attack
  • The presence and severity of associated complications

A patient with a heart attack without complications spends about two to three days in a CCU before being transferred to a step-down unit. A step-down unit offers less intensive care than the CCU but still permits continuous ECG monitoring to screen for abnormal heart rhythms or other complications. The patient usually goes home five to seven days after hospital admission.

What Are The Goals Of Care In The CCU?

Care in the CCU focuses on:

  • Relief of chest pain and anxiety
  • Further assessment (diagnostic tests) to confirm a diagnosis
  • Limiting the size of the heart attack and the area of heart muscle that dies
  • Reducing the work of the heart
  • Identifying, preventing, and treating complications from the heart attack

In the CCU:

  • Care for the patient begun in the emergency setting continues
  • Additional diagnostic tests are ordered
  • Doctors determine if a patient needs an angioplasty
  • The patient’s level of activity and diet is restricted

What Tests And Treatments Occur In The CCU?

ECGs: In addition to the continuous ECG recording, sequential (i.e., daily) 12-lead electrocardiograms (ECG) are obtained to help confirm the diagnosis of a heart attack. Repeat ECGs also help to identify evidence of ongoing ischemia, which is insufficient blood flow to heart muscle or other complications.

Blood work: Further blood samples are also obtained every six to eight hours for 24 hours to measure cardiac enzyme levels. Increased levels of certain cardiac enzymes suggest the presence of damage to heart muscle and are an important means of confirming a diagnosis of a heart attack.

Additional diagnostic tests may include:

  • Echocardiography
  • Nuclear imaging
  • Cardiac catheterization/coronary angiography

Other tests may be performed on selected patients, including

  • Invasive monitoring with a Swan-Ganz catheter. Called right heart catheterization, this provides information about the heart’s functioning, potential complications, and the need for (or response to) specific treatments. It is more commonly performed in patients with signs of heart failure or damage to the heart walls or valves.
  • Use of medications such as nitrates, beta blockers, and angiotensin converting-enzyme (ACE) inhibitors to reduce the work load of the heart. This is one way of limiting the size of the infarction (region of dead heart muscle cells).
  • Use of thrombolytic clot busters drugs to clear a coronary artery that has been blocked by a blood clot
  • Use of antiarrhythmic drugs to treat arrhythmias, which are abnormal heart rhythms.
  • Use of a pacemaker, a machine implanted into the chest that regulates heart rhythm.
  • Use of medications for an abnormally slow heart rhythm (bradycardia) or low blood pressure (hypotension) due to a block in the transmission of the heart’s electrical impulses.
  • Use of anticoagulants, medications that made the blood less sticky and less likely to clot. These can be used in combination with clot buster drugs or to prevent blood clots from forming in the heart chambers or leg veins after a heart attack.
  • Use of medications to treat heart failure if signs of heart failure are present. These include shortness of breath due to fluid in lungs and/or leg swelling.

Depending on the results of these diagnostic and therapeutic procedures, some patients are identified as needing treatments other than medications, including:

  • Coronary angioplasty
  • Coronary artery bypass surgery

Diet And Activity Levels

Additional precautions taken during the stay in the CCU and step-down unit, include

  • Restricting the diet

    For the first 24 hours, the patient is placed on a clear liquid diet to reduce the possibility of aspiration due to nausea and vomiting. A healthy food plan, including complex carbohydrates and fiber-rich foods, is later introduced. All individuals who have suffered a heart attack need to permanently adopt a healthy diet.

  • Limiting activity levels

    All patients are initially placed on bed rest. Patients who are stable, free of pain, and free of complications are sometimes to get out of bed to use the commode. Patients who remain free of complication often begin limited physical activities within 24 hours.

Progression Of Activity

Days 1-2

  • Sitting up with feet dangling over the side of the bed
  • Lifting and lowering of the arms, called range-of-motions exercises, to prevent muscle and joint stiffness and to prevent blood clots from forming in the legs

Days 3-4

  • Bathing and dressing while sitting on the bed or in a chair
  • Taking short walks around the hospital room
  • Taking supervised walks outside the hospital room
  • Showering without shampooing hair (no raising of arms above head)

Days 5-7

  • Walking about 600 feet three times a day
  • Shampooing hair (activities with arms over the head)
  • Climbing stairs with supervision
  • Undergoing an exercise tolerance test

After several days in the hospital, a patient with an uncomplicated heart attack can go home. Physical activity is then gradually increased over the next three to six weeks. Doctors may recommend the patient attend cardiac rehabilitation.

Nice To Know:

While still hospitalized, the patient may get to know members of the cardiac rehabilitation team. Cardiac rehabilitation services can involve many health care providers, including:

  • Doctors, including the family doctor, a heart specialist or cardiologist, and a surgeon.
  • Nurses
  • Exercise specialists
  • Physical and occupational therapists
  • Dietitians
  • Psychologists or other behavior therapists


What Are The Complications Of A Heart Attack?

Heart attacks vary widely in the amount of damage caused and whether there are any complications. Some people may suffer a mild heart attack with no associated complications, which is called an uncomplicated heart attack. Others may suffer a more extensive heart attack with a wide range of complications. Fortunately, treatments can prevent or reduce the impact of complications if they occur.

Complications depend on the:

  • Location of heart muscle damage (i.e. the right or left ventricles)
  • Extent of heart muscle damage
  • Time after the heart attack (i.e., immediate or weeks later)

Complications include:

Arrhythmias (Abnormal Heart Rhythms)

The heart is normally driven by electrical impulses that follow specific pathways through the heart muscle. A heart attack damages heart muscle and often disrupts these electrical pathways. Other stimulation of the body’s nervous system and certain heart medications can also disturb the heart’s electrical impulses. These changes cause abnormal heart rates and rhythms, called “arrhythmias.”

Need To Know:

Some arrhythmias, such as atrial arrhythmias, such as atrial fibrillation or atrial flutter are mild. But others, such as ventricular arrhythmias or complete heart block, are life threatening, occur without warning, and usually happen within the first 24 hours after a heart attack.

Arrhythmias are a major cause of death following an acute heart attack. Early defibrillation (applications of electrical shocks to the heart) by rescue workers, combined with early detection and treatment of arrhythmias in coronary care units, have dramatically reduced both pre-hospital and in-hospital deaths caused by abnormal heart rhythms.

Both continuous ECG monitoring and standard 12-lead electrocardiograms help to screen for arrhythmias.

Arrhythmias may be treated with:

  • Medications
  • Electrical cardioversion, which is the application of electric shocks to the heart through the chest wall
  • Pacemakers, which regulate very slow heart rates due to blocks in the transmission of electrical impulses

Recurrent Ischemia Or Heart Attack

About 20 to 30 percent of heart attack patients experience pain that occurs after the heart attack. Called “postinfarction angina,” this indicates that remaining blood flow to the heart muscle is inadequate. These patients are at increased risk for a subsequent heart attack, called reinfarction.

About 5 to 20 percent of these patients will experience another heart attack in the first six weeks following the original one. This second event may involve the same region of heart muscle or an entirely new region.

Aggressive management of angina following a heart attack helps to reduce the risk of a subsequent heart attack. Patients who experience such angina usually undergo immediate cardiac catheterization and cardiac angiography.

This is often followed by

  • Angioplasty or
  • Coronary artery bypass surgery

Both of these invasive procedures restore blood flow to the heart muscle and lower the risk of a subsequent heart attack.

Heart Failure

Damage to heart muscle from a heart attack may leave the heart unable to pump effectively. If 30 percent or more of the heart muscle in the wall of the left ventricle has been affected, it is likely the patient will develop congestive heart failure.

These patients may experience shortness of breath because of fluid in lung airways. This is caused by the fact that the heart cannot effectively pump blood forward through the body. This condition can usually be treated effectively with medications but may require cardiac bypass surgery.

Cardiogenic Shock

If 40 percent or more of the left ventricle’s muscular wall has been affected, cardiogenic shock may occur. In cardiogenic shock, not enough functional heart muscle remains to pump blood to body tissues and organs to sustain important bodily functions. The heart is not able to provide sufficient blood flow to organs such as the brain, kidneys. As a result, the patient experiences very low blood pressure, rapid heart rate, mental confusion, decreased urine output, and cold arms and legs.

Patients with cardiogenic shock are treated with medications that either increase the amount of blood pumped or reduce the pressure the heart is pumping against. Some individuals may receive a device called an intraaortic balloon pump. The pump is inserted into the aorta, the major blood vessel that supplies blood to the body from the heart. Inflation of the pump increases the blood pressure in the aorta, which, in turn, increases blood flow to the coronary arteries and peripheral (far away) body tissues.

Individuals who experience a heart attack involving the wall of the right ventricle may show signs of right heart failure, such as distended neck veins and leg swelling. These individuals are usually treated with medications.

In many cases, the best treatment for cardiogenic shock is bypass surgery.

For detailed information about bypass surgery, go to Cardiac Bypass Surgery.

Thrombus (Blood Clot) Formation

Erratic blood flow and a lack of blood flow in parts of the heart damaged by the heart attack can cause clots to form in the heart’s chambers. This is especially true if the heart attack has involved the tip of the left ventricle or when an aneurysm has formed.

Inactivity due to bed rest increases the risk of blood clots forming in the deep veins of the legs. These clots can break off and travel through veins to the lungs, where they may cause a blood clot in pulmonary arteries.

Need To Know:

Preventive measures can dramatically reduce the risk of blood clot formation in a heart chamber or blood vessel after a heart attack.

  • The use of anticoagulants or blood thinners in patients at high risk for developing blood clots that could travel through the body’s arteries
  • Placing elastic stockings on the legs

Mechanical Complications

When a heart attack damages muscle, this can lead to the formation of tears or holes in the heart’s wall, which in turn affects heart function. These developments are referred to as mechanical complications.

Types of mechanical complications include:

  • Papillary muscle rupture: the tearing of muscle that attaches to heart valves, which are tissue flaps that direct blood flow through the heart
  • Ventricle free wall rupture: the tearing of the heart muscle wall of the left ventricle, causing blood to fill the fibrous sac that surrounds the heart
  • Ventricular septal rupture: the tearing of the wall between the right and left ventricles, causing blood flow to pass between these heart chambers
  • Aneurysm formation: the dilation or enlargement of a heart chamber due to weakness of its muscular wall

These complications are rare, but can cause varying degrees of heart problems and even death. Complications such as ventricular wall rupture may occur within two weeks of the heart attack, while others such as aneurysm formation may happen weeks or months later. The outcome depends on the degree of damage and swiftness of detection and treatment.

Screening for mechanical complications includes:

  • Watching for signs of heart failure, such as shortness of breath or leg swelling
  • Listening with a stethoscope for new heart murmurs, which would suggest that heart valves are not working properly or that blood is flowing through the wall that divides the ventricles
  • Echocardiography to look at the structure and function of the heart chambers, including blood clots associated with aneurysm formation
  • Electrocardiography to look for electrocardiogram (ECG) changes that may occur with aneurysm formation.
  • Chest x-ray to look for “bulging” of the left ventricle, which would suggest an aneurysm

Doctors and other members of the medical team closely monitor patients for such complications. Monitoring continues after patients leave the hospital at follow-up appointments. Tests performed prior to hospital discharge can often determine the potential for such future problems.


Acute pericarditis, the short-term inflammation of the fibrous sac that encloses the heart, may occur early after a heart attack. Symptoms include pain and fever. A pericardial friction rub may be heard with a stethoscope. This finding is helpful in distinguishing between pericarditis and angina that is occurring after a heart attack.

The increased use of clot buster drugs has decreased the frequency of pericarditis. These medications limit the extent of both heart muscle damage and inflammation. If pericarditis does occur, it can be treated with aspirin.

What Tests Are Used To Diagnose And Further Evaluate A Heart Attack?

A variety of diagnostic tests can be performed to:

  • Confirm that a heart attack has occurred
  • Provide additional information that can guide treatment, and/or
  • Determine the long-term outcome or prognosis in someone who has suffered a heart attack

Some tests, such as sequential electrocardiograms or blood tests, are performed on all patients suspected of having suffered an acute heart attack. Others, such as coronary angiography, are performed only on selected patients.

Tests performed on an individual with a suspected or confirmed heart attack include:

Sequential (Serial) Electrocardiograms (ECGs)

Routine or standard 12-lead electrocardiography is the most commonly performed test in cardiology. It is also the most important diagnostic test in someone with a suspected recent heart attack. This painless test produces an electrocardiogram (ECG), which is a record of the heart’s electrical activity.

In this test, surface electrodes attached to wires (leads) are applied to the skin of the chest and limbs. These leads send the heart’s electrical signals to the electrocardiograph machine, which records this information on paper. The ECG shows a series of waves (P waves, QRS complex, T waves) that represent the electrical events of heart chambers and conduction pathways.

Among other things, a standard 12-lead ECG can demonstrate disturbances in the heart rate or rhythm as well as evidence of damage to the heart muscle. For example, an ECG in someone with an acute heart attack affecting the entire wall of heart muscle may show

  • ST segment elevation (an ST segment above the baseline)
  • T wave inversion (upside-down T waves)
  • And later, deep Q waves

These ECG signs are all consistent with a Q-wave heart attack.

Conversely, the ECG of someone with a non-Q-wave heart attack may show

  • ST segment depression (an ST segment below the baseline)
  • T wave inversion
  • No abnormally deep Q waves

This diagnostic information is important as treatments for these two types of heart attack differ.

Need To Know:

Sequential or multiple ECGs are important because abnormalities are not always present on a single ECG or may be difficult to interpret. Patients in a hospital for a heart attack usually have a daily ECG. Sequential ECGs are also helpful in determining if someone has not suffered a heart attack if all tests appear normal.

Blood Tests

Blood tests are performed to evaluate organ function in a patient with a heart attack. A particularly important diagnostic test is the measurement of cardiac or heart enzymes. When heart muscle is damaged, these enzymes are released into the blood. Their measurement is one of the best ways to confirm a heart attack has occurred.

The first blood sample for this test is usually taken in the emergency room. Additional blood samples are obtained every six to eight hours for the first 24 hours after hospital admission.

Chest X-ray

The chest X-ray uses a beam of ionizing radiation to obtain images of the heart, lungs, and ribs. It allows a physician to view the size of the heart, and may reveal heart enlargement due to muscle damage from a heart attack. Alternatively, a chest X-ray may show fluid in lung airways due to heart failure caused by the heart attack.

In addition to diagnosing complications of a heart attack, a chest X-ray also may help with making a diagnosis. For example, it can reveal evidence of a lung problem, such as pneumonia or pneumothorax or rib fracture that is causing the chest pain.


Echocardiography is a noninvasive diagnostic test that uses ultrasound (high-frequency sound waves) to

  • Visualize the structures of the heart
  • Assess how well the heart is working
  • Obtain information about blood flow within the heart

An ultrasound probe is placed on the chest and sound waves are directed through the probe to the heart. A computer shows images of the heart on a video screen by “reading” echoes of the sound waves as they bounce off the heart. This procedure does not involve any exposure to radiation and is painless.

Echocardiography is particularly useful for evaluating for

  • Potential complications of a heart attack including heart wall or valve damage or blood clot formation in heart chambers
  • Assessing a patient’s long-term prognosis if he or she is unable to exercise and cannot undergo a stress test

Nuclear Imaging

Heart function can be assessed by injecting radioactively labeled substances called “tracers” into veins. The distribution of this radioactive material is tracked with special gamma-camera detectors. The resulting images, called scans, show the distribution of the radioactive tracer within the cardiovascular system. Two commonly used substances are thallium-201 and technetium-99m MIBI.

Nuclear imaging is useful for:

  • Assessing blood flow to heart muscle, called “myocardial perfusion imaging”
  • Identifying regions where blood flow to heart muscle is insufficient, called myocardial ischemia. This results in damage to heart muscle cells, called myocardial infarction.

Thallium-201 is sometimes injected intravenously while a person is exercising on a treadmill or bicycle during the exercise tolerance test. This improves the sensitivity and specificity of the stress test.

The thallium travels through the bloodstream to the heart where it is taken up by heart muscle cells. Parts of the heart that are scarred due to a heart attack or don’t have as much blood flow during exercise do not accumulate as much thallium as normal tissue. These areas appear as cold spots – areas where heart muscle cells take up less thallium on scans.

Technetium-99m MIBI (also called technetium-99m sestamibi) may be used to image blood flow in a process called blood pool imaging. In this procedure, the technetium is attached to blood cells or blood protein before being injected into a vein. This technique allows imaging of blood flowing through the heart and major blood vessels, which is useful in evaluating the heart’s pumping ability.

Exercise Tolerance Or Stress Test

The exercise tolerance test, also known as the “stress test” or “stress ECG,” measures the heart’s response to exercise. An electrocardiograph machine records the heart’s electrical activity while the patient increases his or heart rate by walking on a treadmill or riding a stationary bicycle.

During this activity, the physician or other trained personnel asks if the person is experiencing any symptoms such as chest pain and closely monitors the ECG to make sure the person does not overwork his or her heart.

In addition, the person may receive an injection of thallium isotope (a radioactive material), which makes the heart and its vessels visible to a special, computer-linked camera. The camera records how the heart moves and which parts of the heart muscle are short of blood during the exercise (see Nuclear imaging above).

A stress test can show if the arteries that supply blood to the heart are partially blocked, as may occur with coronary artery disease. It cannot, however, identify exactly where or how severely the coronary arteries are blocked. In these cases, coronary angiography may be necessary.

Need To Know:

A stress test can be performed 14 to 21 days after the heart attack to assess a patient’s ability to perform routine tasks and his or her long-term prognosis.

Cardiac Catheterization And Coronary Angiography

Cardiac catheterization and coronary angiography provide information about

  • The anatomic structures of the heart
  • Blood pressure inside the heart chambers
  • The size and location of blockages in the coronary arteries

A thin tube called a catheter is inserted into an artery in the forearm or groin and “snaked” through blood vessel until it reaches the coronary arteries. Dye is then pumped through the catheter, so that the heart and coronary arteries can be visualized on a special video screen.

Coronary angiography can pinpoint narrowing, obstruction, and other abnormalities of the coronary arteries and is an essential test if the doctor is considering angioplasty or coronary artery bypass surgery. This procedure usually takes about 60 to 90 minutes. Patients receive an anesthetic or numbing agent to avoid discomfort.

Because coronary angiography is invasive, it is not routinely performed in all individuals who have had a heart attack. It should not be performed in individuals who are not candidates for coronary angioplasty or surgery.

What Medications Are Used In The Treatment Of A Heart Attack?

Treatments for a heart attack can be broadly divided into four broad categories:

  • Cardiovascular medications
  • Angioplasty
  • Coronary artery bypass surgery
  • Lifestyle changes to reduce the risk of a repeat heart attack or other heart problems, called secondary prevention

Medications used to treat heart attacks include those used in the hospital as well as after hospital discharge.

Medications in the hospital setting are used to:

Medications To Relieve Chest Pain And Anxiety

Major medications used to relieve chest pain include nitrates such as nitroglycerin and narcotic pain relievers such as morphine. Benzodiazepines, which are minor tranquilizers or antianxiety agents can help relieve anxiety.

Need To Know:

Nitrates, such as nitroglycerin, are used to treat chest pain associated with a heart attack as well as angina. Nitrates work by relaxing smooth muscle, including the smooth muscle in the walls of blood vessels. This causes them to dilate or open up, which improves blood flow to the heart and rest of the body.

This widening of arteries also lowers resistance to blood flow and blood pressure, which lowers the work of the heart. Dilation of veins decreases the amount of blood flow returning to the heart, which also decreases the heart’s work load.

Nitrates improve blood flow to the heart and decrease work of the heart. Both of these events relieve pain due to inadequate blood flow (thus, oxygen supply) to heart muscle.

Nitrate medications comes in a variety of forms including:

  • Pills that dissolve under the tongue
  • Pills that are swallowed
  • Mouth sprays
  • Ointments or creams
  • Skin patches
  • Forms for intravenous administration

Intravenous nitroglycerin is recommended for the first 24 to 48 hours after a heart attack in patients with :

  • An acute heart attack complicated by congestive heart failure
  • A large heart attack affecting the front wall of the heart, called an anterior-wall myocardial infarction
  • Persisting insufficient blood flow to heart muscle, as detected by pain and ECG
  • Hypertension or high blood pressure

Use of nitroglycerin beyond 48 hours is useful if the chest pain returns or if persistent lung congestion due to heart failure occurs.

Individuals with an abnormally low blood pressure or slow heart rate should not receive nitrates because of their tendency to lower blood pressure. Side effects of nitrates include headache and occasional faintness.

Morphine and other narcotic pain relievers are used to relieve chest discomfort associated with a heart attack. Repeat dosages of morphine can be given intravenously frequently if breathing remains normal and no signs of toxicity occur. Side effects of narcotic pain relievers include nausea and pruritus (itching).

Medications To Limit The Size Of The Heart Attack: “Clot Busters”

During a heart attack, most damage to heart muscle occurs in the first six hours. Treating a heart attack during the first two hours is essential to preventing or reducing heart muscle damage.

Most heart attacks are caused by a blood clot blocking a coronary artery. Using thrombolytic agents or “clot busters” that can break down blood clots and restore blood flow through the artery can limit heart muscle damage.

Thrombolytic agents include:

  • Streptokinase
  • Anisoylated plasminogen-streptokinase activator complex (antistreplase)
  • Tissue plasminogen activator (t-PA)

Although these medications work slightly differently, they all activate an enzyme called “plasmin,” which breaks down fibrin in blood clots.

Need To Know:

Giving a clot buster within several hours of an acute heart attack restores blood flow and significantly reduces damage in most cases where a coronary artery has been blocked by a blood clot. The earlier these drugs are used, the greater the benefit.

  • Giving thrombolytics within one hour after a Q-wave heart attack restores blood flow in up to 80 percent of cases.
  • Using thrombolytics within two hours of the onset of chest pain cuts the death rate to half that of patients who received therapy after six hours of pain.

Minutes count! The goal of many medical facilities is to have a “door-to-needle” time of 30 minutes of less – from when a patient enters to when he or she receives the clot buster medication.

Clot buster therapy is sometimes followed by treatment with blood thinners such as heparin to prevent future clot formation. Blood thinners can be given intravenously or under the skin, depending on type of drug and the patient’s risk for future problems due to blood clots.

Thrombolytic treatment is appropriate for patients with an acute heart attack who:

  • Can begin treatment within 12 to 24 hours of the onset of symptoms (preferably less than 12 hours)
  • Have ST segment elevation in two or more leads on an electrocardiogram or ECG, consistent with an acute Q-wave heart attack affecting the entire thickness of heart muscle
  • Have other ECG changes consistent with a heart attack affecting the front wall of the heart

Thrombolytics probably do not help people

  • With pain that has lasted for longer than 24 hours
  • Who only have ST segment depression on ECG.This ECG finding is suggestive of a non-Q-wave heart attack, which often only affects the innermost layer of the heart muscle.

People at risk for bleeding should not receive thrombolytic agents. These include people

  • Recovering from recent surgery
  • With active bleeding from stomach ulcers
  • With very high blood pressure
  • With a history of a recent stroke, head injury, or a bleeding disorder

An alternative to thrombolytic therapy is coronary angiography followed by percutaneous transluminal coronary angioplasty (PTCA) referred to as “primary PTCA.”

Other drugs can help limit the size of the damage by reducing the work load of the heart.

Medications To Reduce The Work Load Of The Heart

How well the heart works after a heart attack depends largely on how much heart muscle was damaged. Medications that decrease the work load and the oxygen needs of the heart can

  • Reduce the size of the area of dead heart muscle
  • Optimize the amount of remaining healthy heart muscle

Drugs that decrease the work load of the heart include:

  • Nitrates
  • Beta blockers
  • Angiotensin converting enzyme (ACE) inhibitors

Beta blockers

Beta blockers have long been used in the treatment of angina and hypertension (high blood pressure).

Intravenous beta blockers given within the first several hours of the onset of a heart attack improve the prognosis (outcome) by:

  • Reducing the size of the infarct (area of dead muscle cells)
  • Lowering the chances of a repeat heart attack
  • Reducing the risk of deadly abnormal heart rhythms such as ventricular fibrillation

All of these benefits reduce the risk of death.

Treatment with beta blockers within the first 24 hours of the onset of a heart attack is recommended for all patients who can tolerate them. Beta blocker therapy is especially useful in individuals with continuing or recurrent pain or abnormally fast heart rhythms called tachycardias.

Beta blockers reduce the heart’s work load by:

  • Slowing the heart rate
  • Reducing how hard the heart pumps, called contractility

All of these effects lower blood pressure as well as heart muscle oxygen requirements.

Due to the actions of beta blockers on the heart, blood vessels, and lungs, some people may not be able to tolerate beta-blocker therapy, including those with:

  • Abnormally low blood pressure or hypotension
  • Abnormally slow heart rate (bradycardia)
  • Heart failure
  • Asthma or chronic obstructive pulmonary disease (COPD)

Side effects of beta blockers may include:

  • Fatigue
  • Depression
  • Erectile dysfunction
  • Hyperglycemia or high blood sugar level
  • Undesirable changes in blood lipid levels, such as increased triglyceride levels and lower levels of “good” (HDL) cholesterol

Some of these side effects can be reduced by lowering the dosage.

Angiotensin converting enzyme (ACE) inhibitors

Angiotensin converting enzyme (ACE) inhibitors are drugs used in the treatment of:

  • Hypertension or high blood pressure
  • Heart failure
  • Diabetic nephropathy, which is kidney disease due to diabetes
  • Myocardial infarction or heart attack

Need To Know:

Using angiotensin converting enzyme (ACE) inhibitors after a heart attack:

  • Limits undesirable structural changes to the heart chamber that pumps blood through the body called “ventricular remodeling”
  • Lowers the frequency of complications such as recurrent angina and heart failure
  • Reduces the risk of death from the heart attack
  • Reduces the risk of a subsequent heart attack

The benefits of ACE inhibitor therapy add to the benefits of treatment with beta blockers (see above) and aspirin and are greatest in individuals with impaired ventricular function, which is inadequate heart pumping, and full-blown heart failure.

ACE inhibitors should be given 24 hours or more after stabilization with thrombolytic drugs and continued indefinitely in individuals with impaired ventricular function.

ACE inhibitors work by blocking the conversion of the inactive angiotensin I to active angiotensin II. The resulting lower level of angiotensin II circulating in the bloodstream reduces blood pressure and the work of the heart because of:

  • Less blood vessel constriction or narrowing caused by angiotensin II. TThis reduces resistance to blood flow through blood vessels, putting less strain on the heart.
  • Less retention of sodium and water by the kidneys in response to angiotensin II. This results in a lower volume of blood that has to be pumped by the heart.

The most common side effect of ACE inhibitors is a reversible dry cough. Other side effects may include:

  • Headache
  • Dizziness
  • Fatigue
  • Hyperkalemia or high potassium levels

Infrequent and rare side effects include a reduction in the number of white blood cells, called neutropenia, and a reversible skin rash with one type of ACE inhibitor.

Medications To Prevent And Treat Complications

This set of drugs includes an assortment of agents used to treat complications of a heart attack, including:

  • Aspirin
  • Antiarrhythmic agents
  • Drugs for heart failure
  • Anticoagulants or blood thinners


Aspirin decreases clot formation by reducing platelet adhesion. This is the “sticking together” of a type of blood cell involved in blood clot formation. Aspirin therapy has been shown to decrease the risk of death associated with a heart attack as well as reduce the risk of a subsequent heart attack.

Unless contraindicated, aspirin should be started immediately and continued indefinitely on a daily basis.

Other drugs that reduce platelet adhesion may be substituted if the person is allergic to aspirin or does not respond to treatment.

Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) are useful for treating chest pain due to pericarditis (inflammation of the sac that encloses the heart), which may occur after a heart attack.

Antiarrhythmic agents

Antiarrhythmic agents refers to a variety of drugs used to treat abnormal heart rhythms or arrhythmias associated with a heart attack.

These drugs are divided into four classes:

  • Class I: These are sodium channel blockers including drugs such as quinidine, procainamide, and lidocaine. These agents must be used with caution as they can also depress left ventricular function (heart pumping) and promote or cause arrhythmias.
  • Class II: These drugs are beta-blockers and examples include atenolol and metoprolol. These agents are used to control supraventricular tachycardias (arrhythmias originating above the ventricles) and also help to suppress dangerous ventricular arrhythmias such as ventricular tachycardia and ventricular fibrillation.
  • Class III: Examples of these drugs are amiodarone and sotalol. Amiodarone is the most powerful antiarrhythmic drug, but its side effects limit its use. Sotalol is also a beta-blocker, with side effects and other actions similar to those of other beta-blockers. It is used to treat atrial fibrillation and atrial flutter as well as ventricular arrhythmias.
  • Class IV: These drugs are calcium channel blockers, which slow the heart rate and dilate or open up blood vessels. These drugs are used to control abnormally rapid rhythms such as atrial fibrillation as long as signs of heart failure or heart block are not present. Examples include verapamil and diltiazem.

In addition to the above four classes of antiarrhythmic drugs, there are also some miscellaneous drugs:

  • Digoxin – This medication increases the strength of heart muscle contractions and is useful in the treatment of heart failure. Because digoxin also slows conduction of the heart’s electrical impulses, it is also useful in controlling atrial fibrillation, atrial flutter, and atrial tachycardia.
  • Adenosine – This drug slows or blocks the conduction of electrical impulses. Since it is only available in intravenous form and only works for a short time, adenosine is only used as acute treatment for supraventricular tachycardias.

Most of the above drugs treat rapid or irregular heart rhythms. Slow heart rhythms (bradycardia) or asystole (cardiac standstill) are treated with atropine or similar drugs. In some cases, a pacemaker may be necessary.

Need To Know:

The selection of the antiarrhythmic drug depends on the type of abnormal rhythm and clinical circumstances. Another way of treating arrhythmias is electrical cardioversion. This involves application of electrical shocks to the chest to convert the abnormal heart rhythm to a normal rhythm.

Electrical cardioversion is used to stop all life-threatening tachycardias or rapid heart rhythms. Cardioversion of ventricular fibrillation to sinus rhythm is referred to as defibrillation. Cardioversion is also used to stop atrial flutter or atrial fibrillation associated with cardiovascular instability or ischemia.

Drugs for Heart failure

Drugs commonly used to treat heart failure that may occur with a heart attack include:

  • Diuretics, which reduce the blood volume by causing the kidneys to get rid of more sodium and water
  • Nitrates
  • ACE inhibitors

Individuals with very low blood pressure due to cardiogenic shock may require treatment with inotropic agents, which are drugs that increase the force of heart contraction. Two examples are dopamine and dobutamine.

These drugs increase the vigor of heart pumping, which in turn increases the amount of blood pumped. The higher cardiac output increases blood pressure and allows more body tissues to receive adequate blood flow.


Anticoagulants or blood thinners differ from thrombolytic agents in that they prevent blood clots from forming as opposed to dissolving them.

Good candidates for treatment with anticoagulants such as heparin after a heart attack include those who are:

  • Undergoing percutaneous or surgical revascularization – the reestablishment of the blood supply to a portion of muscle
  • Receiving the thrombolytic agent alteplase
  • Receiving nonselective thrombolytic agents, such as streptokinase, urokinase, or antisteplase, but considered at high risk for complications due to blood clots traveling through the bloodstream.

People receiving nonselective thrombolytic agents who are not at high risk for such blood clots may still benefit from subcutaneous heparin, which is heparin administered under the skin instead of in the veins. The routine administration of intravenous heparin does not appear to benefit these individuals.

What Are The Surgical Treatments For A Heart Attack?

In some cases, medical therapy for a heart attack is not enough. These patients usually undergo surgical treatments for a heart attack including:


Angioplasty refers to the re-opening or unclogging of a blood vessel that is significantly narrowed by plaque. It is most often used in patients with obstruction(s) in one or two coronary arteries. This is called called “single-vessel” or “double-vessel disease,” respectively. Coronary artery bypass surgery remains the treatment of choice for severe multi-vessel disease, where three or more coronary arteries are significantly obstructed.

Angioplasty can involve:

  • Balloon dilation: This involves the insertion of a thin catheter attached to a tiny balloon into the artery that is blocked. When the catheter reaches the site of blockage, the balloon is inflated, flattening the plaque against the arterial wall and enlarging or re-opening the vessel. This technique is called percutaneous transluminal coronary angioplasty, “PTCA,” or “balloon angioplasty.”
  • Mechanical stripping of the inner lining of a blood vessel: This involves removal of plaque from the blood vessel with small surgical instruments.
  • Forceful injection of fibrinolytics: This involves injection of drugs that break down fibrin in blood clots, which may be used in conjunction with PTCA.
  • Placement of a stent: A stent, which is a slender tubular structure, is sometimes placed in the blood vessel wall during PTCA to hold open the blood vessel.

In people with a recent heart attack, an alternative to thrombolytic therapy is immediate coronary angiography followed by percutaneous angioplasty of the lesion responsible for the heart attack. This treatment is called “primary PTCA.”

Primary PTCA is considered most strongly in individuals who:

  • Have evidence of an acute Q-wave heart attack
  • Can undergo PTCA within 12 hours of the first symptoms (or beyond 12 hours if pain persists)
  • Can have the procedure performed by a skilled and experienced operator in a setting where emergency surgery can be performed

Other individuals who may benefit from primary PTCA include those in whom thrombolytic therapy is not appropriate due to risks.

Coronary angiography and evaluation for possible PTCA is also useful at a later point for some individuals. These especially include those:

  • experiencing angina after the heart attack or instability of cardiovascular parameters (e.g., unstable blood pressure), or
  • scheduled for repair of certain mechanical from a heart attack

Coronary angiography and PTCA are not considered useful

  • within days of having received thrombolytic therapy
  • in survivors of a heart attack who are not thought to be appropriate candidates for coronary revascularization, the reestablishment of blood supply to a portion of heart muscle.

Coronary Artery Bypass Surgery

Coronary artery bypass surgery, also known also as “bypass surgery” and coronary artery bypass grafting (CABG), is an operation in which

  • a blood vessel is taken from elsewhere in the body (usually a vein from the leg or an artery from the chest)
  • the blood vessel is then used to create an alternate pathway of blood or bypass to the heart.

The procedure is extensive surgery that often requires opening the chest and temporarily stopping the heart. During this time, blood flow is maintained to body tissues by a heart-lung machine, which replicates the pumping action of the heart. (A newer procedure allows the heart to continue to beat, but this procedure is not as widely used.)

One end of the transplanted vessel called a graft is connected below the blockage in the coronary artery while the other end is attached to the aorta, the major artery that carries blood away from the heart and into the body. The bypass procedure is repeated for each blocked coronary artery. For example, “triple bypass” means that three grafts have been placed).

Bypass surgery is generally reserved for individuals

  • Whose coronary artery disease cannot be adequately treated by cardiac medications
  • Cannot be treated with angioplasty
  • Who suffer from intractable or unstable angina

These individuals usually have

  • significant obstruction of the three main coronary arteries
  • depressed pumping action or blockage of the left anterior descending artery

They have typically not responded to intensive medical treatment for angina or have just suffered an acute heart attack.

Bypass surgery is performed in people

  • With an evolving heart attack when pain and ECG findings are unstable
  • Who failed angioplasty (They still have persisting pain or continue to be unstable after angioplasty)
  • Who are undergoing repair of mechanical complications such as a tear in the wall dividing the ventricles (ventricular septal defect) or heart valve insufficiency (“leaky” heart valves)

Other individuals who may benefit from CABG after a heart attack include those who are suffering from cardiogenic shock or who remain unstable after PTCA.

While bypass surgery can limit damage in people with an acute heart attack, it does not cure the underlying coronary artery disease. Many still require medications after CABG. Lifestyle modification and cardiac rehabilitation is recommended.

Recovery time following CABG is influenced by a person’s age, overall health, and cardiac function.

For more detailed information on cardiac bypass surgery, go to Cardiac Bypass Surgery.

Living After A Heart Attack

Simply surviving a heart attack is just the beginning of a long process of recovery.

Heart attack survivors now require shorter hospitalizations than years ago. Most heart attack survivors remain free of complications and are discharged from the hospital five to seven days after admission.

Improved medical treatments, such as the early use of clot busting drugs, beta blockers, and angiotensin converting-enzyme inhibitors, also means that heart attack survivors tend to be healthier after their heart attacks.

Advances in angioplasty and coronary artery bypass surgery also have improved outcomes. Most people who have suffered a heart attack can regain normal or near-normal lifestyles. Some actually enjoy better health than before their heart attacks.

But there are still many questions as recovery begins.

Frequently asked questions about recovery include:

What Happens After Discharge From The Hospital?

After being discharged, the patient is scheduled for follow-up appointments with his doctor. After one to three weeks, he or she may join a cardiac rehabilitation programActivities can be resumed gradually over the next three to six weeks.

Most heart attack survivors return home taking cardiac medications. Some of these are drugs that were started in the hospital. Typical discharge medications include:

  • Aspirin to prevent blood clot formation and lower the risk of subsequent heart attack or death
  • A beta blocker, if tolerated. Beta blockers reduce the chance risk of death following a heart attack by about 25 percent for more than several years.
  • An angiotensin converting enzyme (ACE) inhibitor in a survivor with reduced pumping capability of the heart. ACE inhibitors have long-term beneficial effects following a heart attack, including reducing both undesirable structural changes in the ventricle (ventricular remodeling) and the risk of a subsequent heart attack.

There may be other heart-related medications to treat

  • Hypertension or high blood pressure
  • Heart failure
  • Abnormal heart rhythm

In some cases, especially if cholesterol levels are too high, treatment with a cholesterol-lowering drug, in addition to dietary changes, is needed.

Follow the doctor’s directions when taking medications. Ask questions. If side effects from your medications occur, call the doctor right away.

  • If medications are prescribed by different doctors, always be sure that each doctor knows what the other doctor has prescribed.
  • Bring a list of all medications to each doctor visit.

Nice To Know:

Medication Checklist

For each medication, ask the doctor the following:

  • What does it do?
  • How long should I take it, and how often?
  • If I miss a dose, should I take it late or skip it?
  • Should I take it before or after eating food?
  • Is there anything I should not take with my medication?
  • What side effects might I expect?
  • Do I need any follow-up tests to see if the medication is working?

When Can Routine Activities Be Resumed?

After arriving home, heart attack patients should gradually increase physical activity over the next one to three weeks. If cardiac function is maintained, they can often return to their normal activities within six weeks. A supervised and monitored cardiac exercise program that is customized to the patient’s age, lifestyle, and cardiac status, is generally recommended.

According to the American Heart Association (AHA), most people can return to work within weeks. But if your job requires extensive physical activity, or complications have limited your ability to perform tasks, a different work circumstance may be needed. The AHA offers vocational rehabilitation programs that may be of help.

Heart patients may be concerned about resumption of sexual activity. Such activity is generally fine when the person feels ready. Try these guidelines:

  • Choose a time when they feel relaxed and rested.
  • Wait one to three hours after eating a full meal so digestion can be completed.
  • Select a familiar, peaceful setting that is free from interruptions.
  • If prescribed, take medicine prior to sexual relations.
  • Discuss any concerns with their doctor.

What Is This Feeling Of Depression About?

Although better treatment and earlier rehabilitation programs help people recover swifter from a heart attack, adjusting to the psychological impact can take longer. Many survivors of a heart attack experience feelings of helplessness and depression.

The survivor and his or her family need to confront potential underlying fears and anxieties. Don’t keep feelings bottled up inside. He or she should be encouraged to:

  • Be patient. Feelings of fear, anxiety, depression, or anger are common after a heart attack and usually are temporary.
  • Discuss feelings with his or her medical team, family, and friends.
  • Keep a journal. Often, writing about feelings can help a heart attack victim feel better.
  • Arrange for counseling if depression, anger, or withdrawal persists for more than four weeks. Their doctor can be helpful in arranging this.

What Is Cardiac Rehabilitation And Secondary Prevention?

An important event that helps individuals recover from a heart attack, as well as learn about positive lifestyle changes, is cardiac rehabilitation. Cardiac rehabilitation is a structured program of exercise, education, and support that is designed to:

  • Educate the person about heart disease and its proper management
  • Initiate a supervised, monitored exercise program tailored to the individual’s needs
  • Help the person alter or modify risk factors, such as high blood pressure, smoking, high blood cholesterol, physical inactivity, obesity, and diabetes
  • Provide nutritional guidance
  • Look for signs of depression or anxiety disorders, sexual dysfunction, excessive distress/stress, dependence, and inadequate social support
  • Provide emotional support, counseling, and stress management
  • Assist with vocational guidance (returning to work)
  • Supply information on physical limitations, if appropriate

Cardiac rehabilitation programs are run by specially trained health care professionals and may be held at a hospital or other locations. People usually join a cardiac rehabilitation program within several weeks of leaving the hospital. A physician referral may be required.

At cardiac rehab, participants learn ways to regain confidence, improve strength, and prevent a second heart attack, including:

  • Appropriate exercise
  • A healthy diet with the correct amounts of fat, cholesterol, sodium, and more
  • Weight reduction (if necessary)
  • Smoking cessation (if a smoker)
  • Appropriate management of conditions that are risk factors for a subsequent heart attack including diabetes, high blood pressure, high cholesterol, and stress.

Goals of secondary prevention include:

  • Extending overall survival
  • Improving quality of life
  • Decreasing the need for medical interventions, including angioplasty or coronary artery bypass surgery
  • Reducing the risk of a subsequent heart attack

Heart Attack: Frequently Asked Questions

Here are some frequently asked questions related to heart attack.

Q: I’ve heard I should eat more fish and try to cook with vegetable oils like canola. Why?

A: Cold-water varieties of fish, such as salmon, herring, and tuna – as well as certain vegetable oils like canola oil and soybean oil – are rich in polyunsaturated fatty acids known as omega-3 fatty acids. These fatty acids help to reduce the risk of a subsequent heart attack by preventing blood from clotting and sticking to the artery walls. For maximum benefits, fish should be eaten two or three times a week.

Q: I’m worried I may still need bypass surgery. Is it still as risky as it used to be? How long will I be unable to work?

A: Coronary artery bypass is now done more routinely than in the past. Also, recovery times for bypass surgery have significantly shortened over the years. All bypass patients need to spend a few days in intensive care, but they usually are discharged to the home after about seven days if complication-free. Most people can return to work within several weeks. Of course, every form of surgery has risks. The risks of heart surgery and whether you are a candidate are best explained by a cardiothoracic or heart surgeon.

Q: As well as being a heart attack survivor, I have high blood pressure. Does this mean I will now have to take twice as many heart pills?

A: Many individuals receive a beta blocker after having a heart attack to prevent future heart attacks. If you can tolerate a beta blocker, one may be prescribed for you. Beta blockers are also used to treat hypertension. Therefore, your doctor may consider replacing your current antihypertensive medication with a beta blocker. Alternatively, an angiotensin-converting enzyme (ACE) inhibitor is another drug used to treat hypertension that also improves outcomes in heart attack survivors. Your doctor may decide that an ACE inhibitor is right for you. Many of these medications also come in once-daily formulas, reducing the number of pills you need to take each day.

Q: If I miss a dose of medication, should I double up the next time I’m due to take it?

A: No. Missing a single dose now and then will probably not have any serious consequences. On the other hand, doubling up on the dose can lead to adverse effects, including too low a blood pressure or heart rate. If you miss more than a single dose, you should consult your doctor.

Q: If I think I’m having a heart attack, should I wait and see?

A: Often, it is not easy to tell. But don’t wait more than a few minutes – five minutes at the most. Symptoms include

  • Uncomfortable pressure, squeezing, fullness, or pain in the center of the chest that lasts more than a few minutes, or goes away and comes back
  • Discomfort in other areas of the upper body, which may be felt in one or both arms, the back, neck, jaw, or stomach
  • Shortness of breath, which often occurs with or before chest discomfort
  • Other symptoms such as breaking out in a cold sweat, nausea, or light-headedness

Call 9-1-1 or your local emergency number. Call right away!

Heart Attack: Putting It All Together

Here is a summary of the important facts and information related to heart attack.

  • A heart attack or myocardial infarction happens when heart muscle cells die because they do not receive enough oxygen-rich blood.
  • Most heart attacks are caused by a formation of a blood clot (thrombus) that completely blocks a coronary artery that supplies blood to a region of heart muscle.
  • A coronary thrombus usually forms at a site of a plaque, which are deposits of fatty substances such as cholesterol inside an artery. These clots can result when the plaque ruptures.
  • Warning signs of a heart attack include crushing or burning chest pain or pressure, shortness of breath, sweatiness, nausea, and weakness. The chest pain may spread to other locations including the arms, shoulders, neck, back, and jaw.
  • Chest pain experienced with a heart attack is similar to angina, except that is usually more severe, lasts longer, and is not relieved by rest or nitroglycerin.
  • Symptoms of a heart attack can be confused with symptoms of other conditions including other heart, lung, gastrointestinal (stomach and intestinal), and musculoskeletal (muscle and bone) disorders.
  • Familiarize yourself with warning signs of a heart attack and be prepared to seek immediate medical attention (for yourself or others) if one should occur. Early treatment reduces heart damage and saves lives!
  • Major goals of prehospital and hospital care include relief of chest pain and anxiety; limiting the size of the heart attack and reducing the area of heart muscle that dies; reducing the work of the heart; and preventing and treating complications of a heart attack.
  • Possible complications of a heart attack include abnormal heart rhythms; repeat angina and/or heart attack; inadequate heart pumping (heart failure); blood clot formation; mechanical complications such as a tearing of a heart wall or valve; and inflammation of the sac surrounding the heart called pericarditis.
  • Treatment for heart attack includes medications; angioplasty (unblocking/repair of blood vessel); coronary artery bypass surgery [surgical formation of arterial pathways that ‘bypass’ (go around) the blocked portion of artery]; and lifestyle changes.
  • The first two hours after the onset of symptoms of a heart attack are a critical time for beginning treatment. The use of thrombolytic or clot-buster drugs can re-open an artery blocked by a blood clot. This significantly reducing heart muscle damage and improving outcomes. The prevention and early treatment of dangerous abnormal heart rhythms also saves lives.
  • Most people survive a heart attack and return to work and activities, depending on the severity of the heart attack. Some changes in lifestyle are needed after a heart attack to reduce the risk of future heart problems.
  • Recommended lifestyle changes include exercise as recommended by a doctor, eating healthy foods to lower dietary intake of cholesterol and saturated fats, losing weight, if necessary, smoking cessation (if a smoker), and reducing or better managing stress.
  • These lifestyle changes are addressed in cardiac rehabilitation programs that help individuals regain strength, learn about lifestyle changes, and return to activities after a heart attack.

Heart Attack: Glossary

Here are definitions of medical terms related to heart attack.

Adrenaline: One of the chemical messengers in the body that causes the heart to beat faster.

Angina: Term for choking pain (Latin, throat pain or choking). When coupled with the word ‘pectoris’ (Latin, of the chest), angina refers to a painful, constricting sensation in the chest. Angina is caused by coronary artery disease, which reduces the supply of blood to the heart muscle.

Angioplasty: The reconstruction of damaged blood vessels. Coronary angioplasty is an operation to enlarge a narrowed coronary artery.

Aorta: Great artery that arises from the left ventricle (pumping chamber) of the heart and is the starting point of the body’s arterial system.

Arrhythmia: Disturbance of the heart’s normal rhythm.

Arteries: Blood vessels that carry blood away from the heart and around the body.

Arteriography: Procedure used to make an x-ray picture (arteriogram) of an artery or arterial system after injecting a contrasting dye into the blood stream (see coronary angiography).

Atheroma: Bulging yellow mass or “plaque” that forms within the walls lining the arteries. Atheromas (Italian, porridge) contain a mix of fatty and fibrous scar tissue and, when deposited on the inner wall of an artery, reduce its inner diameter.

Atherosclerosis: Gradual build-up and hardening of atheromas within the arterial walls.

Atria: The two upper chambers of the heart (the left atrium and the right atrium), which take in blood flow from the veins.

Atrial fibrillation: A condition in which the heartbeat is irregular and often unusually rapid.

Atrial flutter: A condition in which the upper chambers of the heart contract rapidly, but the heart rhythm is regular.

Balloon angioplasty: Widening of an artery performed by passing a catheter with a tiny balloon attached to the end of a catheter, up an artery to the site of the blockage. The baloon is inflated against the arterial wall widening the sessel as the blockage is flattened. (also known as percutaneous transluminal coronary angioplasty [PTCA]).

Bradycardia: A slow heart rate (less than about 50 beats per minute).

Cardiac catheterization: Insertion of a catheter (fine tube) into an artery in the forearm or groin and snaking it through the blood vessels until it reaches the coronary arteries. This procedure is used during coronary angiography. See also coronary angiography.

Coronary angiography: Procedure used to make an x-ray picture (angiogram) of the heart’s blood vessels after injecting a contrasting dye into the blood stream.

Coronary angioplasty: See angioplasty

Coronary artery: Artery that delivers blood to the heart. The three major coronary arteries are the left anterior descending artery, left circumflex artery, and the right coronary artery.

Coronary artery disease (CAD): Narrowing of the arteries that supply the heart (also known as coronary heart disease [CHD] and ischemic heart disease [IHD]). The coronary arteries become blocked by atheromas that form within the walls lining the arteries.

Echocardiography: A noninvasive test that uses sound waves to produce images of the heart on a monitor.

Electrocardiography (ECG): Procedure used to measure the electrical activity of the heart muscle. It provides information about how the heart functions. The record produced by ECG is known as an electrocardiogram.

Exercise tolerance (stress) test: Procedure used to measure the heart’s response to exercise (also known as a stress test). During exercise tolerance testing, the individual is asked to ride a stationary bicycle or walk on a treadmill while a physician takes an electrocardiogram. See also electrocardiogram.

Fibrillation: Rapid, uncoordinated contraction (squeezing) of the heart muscle.

Heart block: A condition in which the impulses from the heart’s upper chambers are delayed or blocked from reaching the lower chambers.

Lipids: Group of fatty substances that are stored in the body and can be measured in the blood; they include high-density lipoproteins (HDL; “good cholesterol”), low-density lipoproteins (LDL; “bad cholesterol”), and triglycerides, among other compounds.

Myocardial infarction (MI): Death of tissue in the heart muscle; a “heart attack.”

Myocardial ischemia: Insufficient blood in the heart muscle.

Pacemaker: An electrical device that delivers electrical impulses to produce a heartbeat of desired frequency. Implantable pacemakers are the mainstay of treatment for bradycardia, and are also useful for some tachycardias.

Palpitations: Awareness of the heart beating; the heartbeat may feel fast, slow, forceful, or irregular.

Pericarditis: Inflammation of outer covering of the heart.

Percutaneous transluminal coronary angioplasty (PTCA): See balloon angioplasty.

Pneumothorax: The presence of air or gas in space that holds the lungs.

Plaque: See atheroma.

Prinzmetal’s angina: See variant angina pectoris.

Stress test: See exercise tolerance test.

SVTs (supraventricular tachycardias): Fast heartbeats that originate above the ventricles (in the atria, AV node, or both).

Tachycardia: The term used to describe a rapid heartbeat of greater than 100 beats per minute.

Variant angina pectoris: Angina caused by spasm (sudden contraction [squeezing response]) of the smooth muscle within the coronary arteries (also known as “Prinzmetal’s angina,” or angina inversa). Variant angina occurs almost exclusively when a person is at rest or asleep, often between the hours of midnight and 8 am.

Veins: The blood vessels that carry blood back to the heart.

Ventricles: The two lower chambers of the heart (the left ventricle and the right ventricle), which pump blood out of the heart and into the arteries.

Ventricular tachyarrhythmias: Fast heartbeats that originate in the ventricles.

Heart Attack: Additional Sources Of Information

Here are some reliable sources that can provide more information on heart attack.

Heart Attack Guide: Part Two – Recovery, Rehabilitation, Medications, Exercise, Lifestyle Modifications, Depression 

American Heart Association (national office) 
Phone: (800) AHA-USA1 Heart & stroke info 
Phone: (888) MY HEART Women’s health info 

Mended Hearts, Inc. 
Phone: (214) 373-6300

National Heart, Lung and Blood Institute National Institutes of Health 
Phone: (301) 951-3260


8 Steps to a Healthy Heart: The Complete Guide to Heart Disease Prevention and Recovery from Heart Attack and Bypass Surgery

Robert E. Kowalski, Jack Sternlieg

American Heart Association’s Your Heart: An Owner’s Manual

American Heart Association

Healthy Heart Handbook: How to Prevent and Reverse Heart Disease, Lower Your Risk of Heart Attack and Cancer, Reduce Stress, Lose Weight Without hunger

Neal Pinckney

Johns Hopkins Complete Guide to Preventing and Reversing Heart Disease

Peter O. Kwiterovich

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