Heart attack

Myocardial infarction (MI) or acute myocardial infarction (AMI), commonly known as a heart attack, occurs when blood flow stops to a part of the heart causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw. Often it is in the center or left side of the chest and lasts for more than a few minutes. The discomfort may occasionally feel like heartburn. Other symptoms may include shortness of breath, nausea, feeling faint, a cold sweat, or feeling tired. About 30% of people have atypical symptoms, with women more likely than men to present atypically. Among those over 75 years old, about 5% have had an MI with little or no history of symptoms. An MI may cause heart failure, an irregular heartbeat, cardiogenic shock, or cardiac arrest.

Most MIs occur due to coronary artery disease. Risk factors include high blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol, poor diet, and excessive alcohol intake, among others. The mechanism of an MI often involves the complete blockage of a coronary artery caused by a rupture of an atherosclerotic plaque. MIs are less commonly caused by coronary artery spasms, which may be due to cocaine, significant emotional stress, and extreme cold, among others. A number of tests are useful to help with diagnosis, including electrocardiograms (ECGs), blood tests, and coronary angiography. An ECG, which is a recording of the heart's electrical activity, may confirm an ST elevation MI (STEMI) if a change known as ST elevation is present. Commonly used blood tests include troponin and less often creatine kinase MB.

Warning Signs of a Heart Attack

Don’t wait to get help if you experience any of these heart attack warning signs. Although some heart attacks are sudden and intense, most start slowly, with mild pain or discomfort. Pay attention to your body — and call your emergency number if you feel:

Chest discomfort. Most heart attacks involve discomfort in the centre of the chest that lasts more than a few minutes, or that goes away and comes back. It can feel like uncomfortable pressure, squeezing, fullness or pain.
Discomfort in other areas of the upper body. Symptoms can include pain or discomfort in one or both arms, the back, neck, jaw or stomach.
Shortness of breath with or without chest discomfort.
Other signs may include breaking out in a cold sweat, nausea or light-headedness.

Symptoms Vary Between Men and Women

As with men, women's most common heart attack symptom is chest pain or discomfort. But women are somewhat more likely than men to experience some of the other common symptoms, particularly shortness of breath, nausea/vomiting, and back or jaw pain. Learn about the warning signs of heart attack in women

Heart attacks are usually treatable when diagnosed quickly. However, without treatment, heart attacks can be fatal.

What do women need to know about heart attacks?

Women are less likely to survive heart attacks than men. No one knows why. It may be that women don't seek or receive treatment as soon as men, or that they don't recognize the symptoms of a heart attack, which can be different from the symptoms that men experience. It may be because women's smaller hearts and blood vessels are more easily damaged. Doctors are working on finding answers to these questions. Clearly, it makes sense to prevent heart problems before they start.

Risk factors for a heart attack

Smoking
Diabetes
Age--Risk increases for men older than 45 years of age and for women older than 55 years of age (or after menopause). About 83% of people who die from heart disease are 65 years of age or older.
High cholesterol level
High blood pressure
Family history of heart attack
Race--African Americans, Mexican Americans, Native Americans and native Hawaiians are at greater risk.
Atherosclerosis (hardening of the arteries)
Lack of exercise
Stress
Obesity
Sex (Gender)--More men have heart attacks, although heart disease is the leading cause of death for women.