Acute Myocardial Infarction for Stony Brook University Hospital

Basic Facts

• Myocardial infarction, commonly referred to as heart attack, is the most serious outcome of coronary heart disease, the blockage of the arteries that supply blood to the heart muscle.
• Approximately 1.3 million Americans will experience a first or recurrent myocardial infarction in 2008.
• Most people who have a heart attack wait 2 hours or more after their symptoms begin before they seek medical help, a delay that can result in death or permanent heart damage.

A myocardial infarction (MI) is damage to the heart muscle, or myocardium, that results from a lack of blood flow to the heart. The word acute is used to describe a heart attack because symptoms and damage occur suddenly. People who suffer heart attacks require immediate medical attention. Although heart disease has traditionally been considered a man's disease, it is the leading cause of death among women in the United States. Because heart attack symptoms differ between men and women, many women do not realize that they are experiencing a heart attack and may delay treatment.

WHAT ARE THE SYMPTOMS?

If treatment begins soon after symptoms start, heart attack deaths and heart damage can often be avoided. Each heart attack is different and may have different symptoms.

Although different people make different comparisons to express the discomfort they feel, some common symptoms include:

• Chest discomfort that may start out feeling mild and build in intensity;
• Discomfort in other areas of the upper body;
• Shortness of breath;
• Breaking out in a cold sweat;
• Feeling dizzy, light-headed or nauseated; or
• Belching or vomiting.

Symptoms in Women. Although the most common heart attack symptom in women is chest pain, women often experience heart attack symptoms that are different from men, including:

• Pain in the jaw or shoulder;
• Sweating;
• Nausea;
• Shortness of breath;
• Indigestion or heartburn; and
• Weakness or unusual fatigue.

Physicians recommend that people chew an aspirin as soon as they notice the warning signs of a heart attack, because studies have shown aspirin improves the chances of survival.

CAUSES AND RISK FACTORS

The risk of having a heart attack rises with age for men and women. Other risks factors that contribute to the development of coronary heart disease (CHD) include:

• Smoking;
• Family history of heart disease;
• Diabetes mellitus;
• High cholesterol levels or lipid disorders;
• Hypertension, or high blood pressure;
• Eating a diet high in fat and cholesterol;
• Not exercising regularly;
• Being overweight; and
• Using cocaine.

DIAGNOSIS

The two most common tools physicians use to diagnose MI are electrocardiogram (ECG) and a blood test that identifies chemicals associated with a heart attack. Other tests a physician may use include:

• Angiography;
• ECG stress testing;
• Nuclear stress testing; and
• Echocardiography.

TREATMENT APPROACH

Emergency care. Restoring blood flow to the heart within 1 hour of the onset of a heart attack can prevent or limit damage to the heart muscle and can also decrease the chance of a repeat attack. To restore blood flow to the heart muscle, physicians use thrombolytic therapy, sometimes referred to as clot-busting therapy, or a minimally invasive procedure known as angioplasty.

Post-emergency care. Once emergency treatment for MI has been given and tests have confirmed that a heart attack has occurred, the goals of treatment become addressing severe CHD that may be present, preventing further damage to the heart muscle, and minimizing the risk of a repeat MI.

Medications prescribed to people who have had a heart attack include antiplatelets, beta-blockers, and calcium channel blockers.

In some cases, angioplasty or coronary artery bypass graft surgery may be recommended after a heart attack.

When medication does not adequately increase blood supply to the heart, surgery may be necessary to treat the CHD that causes angina symptoms. Current surgical options for treating angina because of CHD include coronary angioplasty, also called balloon angioplasty, and coronary artery bypass graft surgery.

LIFESTYLE CHANGES

There are some beneficial steps people can take to minimize their risk of having an acute MI. For instance, lifestyle changes can help control high blood pressure, and other risk factors for CHD. These changes include:

• Quitting smoking;
• Eating to reduce high blood cholesterol;
• Maintaining a healthy weight; and
• Being physically active each day.