Heart attack - Overview
Alternative Names
Myocardial infarction; MI; Acute MI
Definition of Heart attack:
A heart attack is when low blood flow causes the heart to starve for oxygen. Heart muscle dies or becomes permanently damaged. Your doctor calls this a myocardial infarction.
Causes, incidence, and risk factors:
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 starves for oxygen and heart cells die.
A clot most often forms in a coronary artery that has become narrow because of the build-up of a substance called plaque along the artery walls. (See: atherosclerosis) Sometimes, the plaque cracks and triggers a blood clot to form.
Occasionally, sudden overwhelming stress can trigger a heart attack.
It is difficult to estimate exactly how common heart attacks are because as many as 200,000 to 300,000 people in the United States die each year before medical help is sought. It is estimated that approximately 1 million patients visit the hospital each year with a heart attack. About 1 out of every 5 deaths are due to a heart attack.
Risk factors for heart attack and coronary artery disease include:
Higher-than-normal levels of homocysteine, C-reactive protein, and fibrinogen may also increase your risk for a heart attack. Homocysteine is an amino acid. C-reactive protein and fibrinogen are linked to inflammation. Fibrinogen is also involved in blood clotting.
- Reviewed last on: 3/30/2007
- Larry A. Weinrauch, MD, Assistant Professor of Medicine, Harvard Medical School, and Private practice specializing in Cardiovascular Disease, Watertown, MA, and Glenn Gandelman, MD, MPH, Assistant Clinical Professor of Medicine, New York Medical College, Valhalla, NY. Review provided by VeriMed Healthcare Network.
References
Mosca L, Banka CL, Benjamin EJ, et al. Evidence-Based Guidelines for Cardiovascular Disease Prevention in Women: 2007 Update. Circulation. 2007; Published online before print February 19, 2007.
Pollack CV Jr. 2004 American College of Cardiology/American Heart Association guidelines for the management of patients with ST-elevation myocardial infarction: implications for emergency department practice. Ann Emerg Med. 2005; 45(4): 363-76.
The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. Clinical Guidelines/Evidence Reports. 2003 May; 3(5233); 1.
Boden WE, O'rourke RA, Teo KK, et al. Optimal Medical Therapy with or without PCI for Stable Coronary Disease. N Engl J Med. 2007 Mar 26; [Epub ahead of print].
