What Is a Heart Attack?

There are about 500,000 heart attack deaths in the U.S. each year. At least 250,000 people die before they even get to the hospital. Many of these deaths could be prevented by acting quickly and by getting treatment right away, especially within the first hour of having chest pain. Women account for nearly half of all heart attack deaths. Between the ages of 40 and 60, as many women die of heart disease as breast cancer. Over a lifetime, heart disease kills five times as many women as breast cancer. Heart disease is our nation's number one killer.

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 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.

A Heart Attack is a life-threatening event. Everyone should know the warning signs of a heart attack and how to get emergency help. Many people suffer permanent damage to their hearts or die because they do not get help immediately.

Each year, more than a million persons in the U.S. have a heart attack and about half (515,000) of them die. About one-half of those who die do so within 1 hour of the start of symptoms and before reaching the hospital.

The heart is a complex, highly specialized, muscular organ in the chest that maintains the circulation of blood throughout the body. Heart attack, or acute myocardial infarction, is the death of heart tissue caused by a complete blockage in one of the arteries that supply blood to the heart (coronary arteries), resulting in an interruption in the blood supply to the heart. When heart tissue is deprived of blood-borne oxygen for longer than 30 minutes (called ischemia), it begins to die. 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 2 hours or more after symptoms begin. Many people wait 12 hours or longer.

A heart attack is an emergency. Call 9-1-1 if you think you (or someone else) may be having a heart attack. Prompt treatment of a heart attack can help prevent or limit lasting damage to the heart and can prevent sudden death.