Heart attack

Myocardial infarction; MI; Acute MI; ST - elevation myocardial infarction; Non-ST - elevation myocardial infarction; NSTEMI; CAD - heart attack; Coronary artery disease - heart attack

Most heart attacks are caused by a blood clot that blocks one of the coronary arteries. The coronary arteries bring blood and oxygen to the heart. If the blood flow is blocked, the heart is starved of oxygen and heart cells die.

The medical term for this is myocardial infarction.

Heart, section through the middle

The interior of the heart is composed of valves, chambers, and associated vessels.

Heart, front view

The external structures of the heart include the ventricles, atria, arteries and veins. Arteries carry blood away from the heart while veins carry blood into the heart. The vessels colored blue indicate the transport of blood with relatively low content of oxygen and high content of carbon dioxide. The vessels colored red indicate the transport of blood with relatively high content of oxygen and low content of carbon dioxide.

Progressive build-up of plaque in coronary artery

Plaque may build-up in a coronary artery at the site of a tear in the lining of the vessel.

Acute MI

A heart attack or acute myocardial infarction (MI) occurs when one of the arteries that supplies the heart muscle becomes blocked. Blockage may be caused by spasm of the artery or by atherosclerosis with acute clot formation. The blockage results in damaged tissue and a permanent loss of contraction of this portion of the heart muscle.

Post myocardial infarction ECG wave tracings

Various phases can be seen through ECG wave tracings following a heart attack. Hyperacute phase begins immediately after a heart attack. Fully evolved phase starts a few hours to days after a heart attack. Resolution phase appears a few weeks after a heart attack. Stabilized chronic phase is the last phase and typically has permanent pathological changes compared to a normal ECG tracing.

Posterior heart arteries

The coronary arteries supply blood to the heart muscle. The right coronary artery supplies both the left and the right heart; the left coronary artery supplies the left heart.

Anterior heart arteries

The coronary arteries supply blood to the heart muscle. The right coronary artery supplies both the left and the right heart; the left coronary artery supplies the left heart.

Heart attack symptoms

Symptoms of a possible heart attack include chest pain and pain that radiates down the shoulder and arm.Some people (the elderly, people with diabetes, and women) may have little or no chest pain. Or, they may experience unusual symptoms (shortness of breath, fatigue, weakness). Women are more likely than men to have symptoms of nausea, vomiting, back or jaw pain, and shortness of breath with chest pain.

Jaw pain and heart attacks

Pain from a heart attack may sometimes radiate to the jaw and teeth. Chest pain is a major symptom of heart attack, but other symptoms such as weakness, shortness of breath, nausea, or vomiting may also occur.

Causes

Symptoms

Exams and Tests

Treatment

Support Groups

Outlook (Prognosis)