A heart attack is when blood vessels that supply blood to the heart are blocked, preventing enough oxygen from getting to the heart. The heart muscle dies or becomes permanently damaged. Your doctor calls this a myocardial infarction.
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.
In atherosclerosis, plaque builds up in the walls of your coronary arteries. This plaque is made up of cholesterol and other cells. A heart attack can occur as a result of the following:
The slow buildup of plaque may almost block one of your coronary arteries. A heart attack may occur if not enough oxygen-containing blood can flow through this blockage. This is more likely to happen when you are exercising.
The plaque itself develops cracks (fissures) or tears. Blood platelets stick to these tears and form a blood clot (thrombus). A heart attack can occur if this blood clot completely blocks the passage of oxygen-rich blood to the heart.
Occasionally, sudden overwhelming stress can trigger a heart attack.
Transfusion reaction - hemolytic (1 image)(Doctor-Reviewed information)
A hemolytic transfusion reaction is a serious problem that occurs after a patient receives a transfusion of blood. The red blood cells that were given to the patient are destroyed by the patient''s own immune system.Blood is classified into differe...Reviewer: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine; and Yi-Bin Chen, MD, Leukemia/Bone Marrow Transplant Program, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 03/02/2009
Septic shock(Doctor-Reviewed information)
Septic shock is a serious condition that occurs when an overwhelming infection leads to life-threatening low blood pressure.Bacteremic shock; Endotoxic shock; Septicemic shock; Warm shock.Septic shock occurs most often in the very old and the very...Reviewer: Andrew Schriber, MD, FCCP. Specialist in Pulmonary, Critical Care, and Sleep Medicine, Virtua Memorial Hospital, Mount Holly, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.Date: 10/18/2008
Septicemia(Doctor-Reviewed information)
Septicemia is the presence of bacteria in the blood( bacteremia) and is often associated with severe disease.Septicemia is a serious, life-threatening infection that gets worse very quickly. It can arise from infections throughout the body, includ...Reviewer: Kenneth M. Wener, MD, Department of Infectious Diseases. Lahey Clinic, Burlington, MA. Review provided by VeriMed Healthcare Network.Date: 07/25/2007