Heart Disease—A Threat to Life

Each year millions of men and women worldwide have heart attacks. Many survive with few aftereffects. Others do not survive. For still others the heart is so damaged that "a return to useful activities is questionable," cardiologist Peter Cohn says, adding: "It is imperative, therefore, to nip heart attacks in the bud whenever possible."

The heart is a muscle that pumps blood throughout the body. In a heart attack (myocardial infarction), part of the heart muscle dies when deprived of blood. To stay healthy, the heart needs oxygen and other nutrients that are carried by the blood. It gets these by way of the coronary arteries, which wrap around the outside of the heart.

Diseases can affect any part of the heart. However, the most common is the insidious disease of the coronary arteries called atherosclerosis. When this occurs, plaque, or fatty deposits, develops in the artery walls. Over a period of time, plaque can build up, harden and narrow the arteries, and restrict blood flow to the heart. It is this underlying coronary artery disease (CAD) that sets the stage for most heart attacks.

Clogging in one or more arteries precipitates an attack when the heart's demand for oxygen exceeds the supply. Even in arteries less severely narrowed, a deposit of plaque can crack and lead to the formation of a blood clot (thrombus). Diseased arteries are also more susceptible to spasm. A blood clot can form at the site of a spasm, releasing a chemical that further constricts the artery wall, triggering an attack.

When heart muscle is deprived of oxygen long enough, nearby tissue may be damaged. Unlike some tissue, heart muscle does not regenerate. The longer the attack, the more damage to the heart and the greater the likelihood of death. If the heart's electrical system is damaged, the heart's normal rhythm can become chaotic and the heart can begin to quiver wildly (fibrillate). In such an arrhythmia, the heart's ability to pump blood effectively to the brain fails. Within ten minutes the brain dies and death occurs.

Thus, early intervention by trained medical personnel is vital. It can rescue the heart from ongoing damage, prevent or treat the arrhythmia, and even save a person's life.