A myocardial infarction (also known as a heart attack) is a life-threatening event in which blood supply and oxygen to an area of heart muscle is blocked. Symptoms include chest pain that spreads to other parts of the body, shortness of breath, dizziness, and nausea. A heart attack is an emergency; call 911 if you think you or someone else is experiencing one. Prompt treatment may prevent sudden death.
What Is Myocardial Infarction?
A myocardial infarction (known more commonly as a heart attack) occurs when the supply of blood and oxygen to an area of heart muscle is blocked, usually by a clot in a coronary artery. Often, this blockage leads to arrhythmias (irregular heartbeat or rhythm) that can cause a severe decrease in the pumping function of the heart and may bring about sudden death. If the blockage is not treated within a few hours, the affected heart muscle will die and be replaced by scar tissue.
Each year, more than a million people in the United States have a myocardial infarction. About half (515,000) of these people die as a result. About one-half of those who die do so within one hour of the start of symptoms and before reaching the hospital.
A Life-Threatening Event
Clearly, a myocardial infarction is a life-threatening event. Everyone should know the warning signs and how to get emergency help. Many people suffer permanent damage to their hearts or die because they do not get help immediately.
Emergency personnel can often stop arrhythmias with emergency CPR (cardiopulmonary resuscitation), defibrillation (electrical shock), and prompt advanced cardiac life support procedures. If care is sought soon enough, blood flow in the blocked artery can be restored in time to prevent permanent damage to the heart. Yet most people do not seek medical care for two hours or more after their symptoms begin. Many people wait 12 hours or longer.
A myocardial infarction is an emergency. Call 911 if you think you (or someone else) may be having a myocardial infarction. Prompt treatment can help prevent or limit lasting damage to the heart and can prevent sudden death.