Reviewed by Brian R. Robinson, MD Each year, approximately 1.5 million Americans experience a heart attack, also called myocardial infarction. The severity of a heart attack varies from person to person, but everyone’s body experiences the stop of blood flow to the myocardium (the heart’s muscular walls).
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 Video Resources: See the heart at work and learn more about cardiac conditions and diagnostics.
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The human heart pumps blood through the arteries continuously throughout a person’s life. The coronary arteries carry oxygen-rich blood to the myocardium; if the flow stops, a myocardial infarction (“death of heart tissue”) occurs. This is another name for a heart attack.
Most people experience a heart attack due to atherosclerosis, or hardening of the arteries, in which plaque builds up on the artery walls. As the arteries narrow due to these cholesterol and fat deposits, blood flow is reduced. Eventually, the body’s demand for oxygen will exceed its ability to supply it, a condition known as ischemia. Prolonged ischemia due to atherosclerosis can lead to a heart attack. Although atherosclerosis is often blamed for a heart attack, it is a particular event like the formation of a blood clot on the fatty plaque that blocks the artery and causes the attack.
The severity of the heart attack is judged by how much heart muscle is involved, the length of the ischemia, and the extent of infarction.
Most heart attacks are several hours long. Approximately one-third of them occur with no previous warning signs. In fact, some people mistake a heart attack for heartburn, a less serious condition. If you suspect that you are having a heart attack, you should seek help immediately.
Heart attacks that occur without warning are usually associated with silent ischemia, random interruptions of blood flow to the heart that are pain-free. Silent ischemia gradually damages the heart tissue over time. An estimated 3 to 4 million Americans may have silent ischemia and not know it. This condition can be detected with an ECG test.
However, many people have conditions that predispose them to a heart attack. Angina, which produces chest pain similar to that of a heart attack, is marked by restricted blood flow to the heart as well. But in the case of angina, blood flow is quickly restored and the heart is not permanently damaged.
Every year, about 5 million people go to the emergency room complaining of chest pains. Only 30% actually are heart attack victims. It is important to know the symptoms.
Symptoms of a heart attack include:
- Shortness of breath
- Chest pain (constant or intermittent)
- Chest pain that radiates to the neck, one or both arms, shoulders, or jaw
- Dizziness
- Nausea
- Lightheadedness
- Weak pulse
- Cold, clammy skin
One-third of all heart attack victims die before reaching a hospital; others make it to the hospital but then suffer life-threatening complications while there. These complications include stroke, heart arrhythmias (irregular heart beats), congestive heart failure, blood clot formation, or an aneurysm.
Others recover fully from a heart attack. Although they are weakened at first, normal activities can usually be resumed within three months of the attack.
The one definitive treatment for cardiac arrest is defibrillation.
But most heart attacks can be prevented. The major risk factors of a heart attack are well known in the medical community. They include:
- High blood pressure
- High cholesterol
- Obesity
- Smoking
- Sedentary lifestyle
- Stress
Men over age 50 with a family history of heart attack are particularly at risk for heart attack. Post-menopausal women are at a higher risk than pre-menopausal women, although high levels of estrogen, which can be attained with hormone replacement therapy, may protect them.
A cardiologist runs many tests on a suspected heart attack victim. Some of those tests include: an ECG, which is done early to assess the condition; an angiogram; and an echocardiogram.
Once the patient has gotten emergency care and the prognosis of heart attack has been confirmed, the usual hospital stay is at least 36 hours. The patient will receive a painkiller, such as morphine, to ease the chest pains.
The cardiologist will usually recommend a medication called a vasodilator, like nitroglycerine, to expand the blood vessels; a beta-adrenergic blocker to quiet down the heart; and aspirin to reduce the risk of blood clot.
While hospitalized, an ECG machine monitors the patient constantly. In some cases, the cardiologist will perform angioplasty to remove a clot or reopen a clogged artery.
During hospitalization, the cardiologist may recommend the insertion of a pacemaker to sense and correct any irregularities associated with the patient’s natural heartbeat.
Some medical experts estimate that up to 30% of fatal heart attacks and follow-up surgeries can be avoided with healthy lifestyle changes. The majority of heart attack sufferers do not take these precautions, however.
To prevent another heart attack, many survivors take aspirin daily to thin the blood and reduce the risk of heart attack. A regular regimen of aerobic exercise is highly recommended. In the first few months of recovery, a heart attack survivor should not exercise alone.
Video Resources: See the heart at work and learn more about cardiac conditions and diagnostics.
