heart attack

A heart attack, also called a myocardial infarction (MI), occurs when the heart muscle is deprived of oxygen to the point that the heart tissue dies.

 

The left and right coronary arteries are the first branches to leave the aorta, the main artery of the body. The coronary arteries supply blood and oxygen to the heart muscle. When these arteries do not deliver enough oxygen, a pain known as angina results. If the heart muscle is deprived of oxygen for a long enough period of time, the heart cells begin to die. This is called a heart attack.

 

The most common symptom of a heart attack is chest pain, or angina. Angina is often described as a feeling of crushing, pressure, fullness, heaviness, or aching in the center of the chest. These sensations may extend into the neck, the jaw, down the left arm, or occasionally to other places.

 

Angina is often associated with other symptoms, including:

 

The type of angina known as stable angina is brought on by exertion and relieved by rest or nitroglycerin. In the type of angina known as unstable angina, the pain is more frequent and more severe. It can occur even when the person is resting. Unstable angina is a medical emergency.

 

Usually, angina is very uncomfortable. However, in some cases, symptoms are mild enough to be discounted as indigestion. A person may deny the chest pain and delay seeking help. Someone who has diabetes may not experience classic angina symptoms. A person with diabetes can have a heart attack without knowing it.

 

Atherosclerosis is the most common cause of heart attacks. Deposits of fat, platelets, and cellular debris build up along the inner wall of the artery. The narrowing of the coronary arteries from atherosclerosis is known as coronary heart disease. It reduces the amount of oxygen-rich blood that can reach the heart.

Heart attacks cannot always be prevented. It is important to control high blood pressure, diabetes, and high cholesterol. A person can lower his or her risk by maintaining a healthy body weight. Physical activity and a diet designed to reduce heart disease can help prevent heart attacks.

Diagnosis of a heart attack begins with a history and physical exam. An electrocardiogram (ECG) can help in the diagnosis. Blood tests are done to measure levels of certain enzymes (released by damaged heart muscle) in the bloodstream. Because these enzymes may not rise for several hours after the pain begins, a person with a suspected heart attack is often admitted to a hospital. Rechecks of these levels over a period of time will determine if a heart attack has occurred.