elnathan Blog: Heart Attack: What Is It?

 When the flow of oxygen-rich blood to a section of heart muscle suddenly becomes blocked and the heart can't get oxygen, then a heart attack happens. If blood flow isn't restored quickly, the section of heart muscle begins to die.

Heart attacks most often occur as a result of coronary heart disease (CHD), also called coronary artery disease. CHD is a condition in which a waxy substance called plaque (plak) builds up inside the coronary arteries. These arteries supply oxygen-rich blood to your heart.
When plaque builds up in the arteries, the condition is called atherosclerosis(ath-er-o-skler-O-sis). The buildup of plaque occurs over many years.
Eventually, an area of plaque can rupture (break open) inside of an artery. This causes a blood clot to form on the plaque's surface. If the clot becomes large enough, it can mostly or completely block blood flow through a coronary artery.

If the blockage isn't treated quickly, the portion of heart muscle fed by the artery begins to die. Healthy heart tissue is replaced with scar tissue. This heart damage may not be obvious, or it may cause severe or long-lasting problems.

Heart With Muscle Damage and a Blocked Artery

Figure A shows a heart with dead heart muscle caused by a heart attack. Figure B is a cross-section of a coronary artery with plaque buildup and a blood clot.

A less common cause of heart attack is a severe spasm (tightening) of a coronary artery. The spasm cuts off blood flow through the artery. Spasms can occur in coronary arteries that aren't affected by atherosclerosis.
Heart attacks can be associated with or lead to severe health problems, such as heart failure and life-threatening arrhythmias (ah-RITH-me-ahs).
Heart failure is a condition in which the heart can't pump enough blood to meet the body's needs. Arrhythmias are irregular heartbeats. Ventricular fibrillation is a life-threatening arrhythmia that can cause death if not treated right away.

SYMPTOMS

• Chest pain or discomfort. Most heart attacks involve discomfort in the center or left side of the chest. The discomfort usually lasts more than a few minutes or goes away and comes back. It can feel like pressure, squeezing, fullness, or pain. It also can feel like heartburn or indigestion.
• Upper body discomfort. You may feel pain or discomfort in one or both arms, the back, shoulders, neck, jaw, or upper part of the stomach (above the belly button).
• Shortness of breath. This may be your only symptom, or it may occur before or along with chest pain or discomfort. It can occur when you are resting or doing a little bit of physical activity.

Other possible symptoms of a heart attack include:

• Breaking out in a cold sweat
• Feeling unusually tired for no reason, sometimes for days (especially if you are a woman)
• Nausea (feeling sick to the stomach) and vomiting
• Light-headedness or sudden dizziness
• Any sudden, new symptom or a change in the pattern of symptoms you already have (for example, if your symptoms become stronger or last longer than usual)

Not all heart attacks begin with the sudden, crushing chest pain that often is symptoms of a heart attack can vary from person to person. Some people can have few symptoms and are surprised to learn they've had a heart attack. If you've already had a heart attack, your symptoms may not be the same for another one. 

Outlook
CHD, which often results in heart attacks, is the leading killer of both men and women in the United States up to 1 million die yearly .
Many more people could survive or recover better from heart attacks if they got help faster. Of the people who die from heart attacks, about half die within an hour of the first symptoms and before they reach the hospital.