What Is a Heart Attack?
What Is Angina Pectoris?
What Is a Stroke?
How does the heart work?
What To Do in an Emergency
What is a heart
Heart attacks result from heart disease
blood vessel disease in the heart. Coronary
heart disease (C.H.D.),
disease (C.A.D.) and
heart disease are more specific
names for heart disease.
What causes a
The medical term for heart attack is
. A heart attack occurs when
the blood supply to part of the heart muscle itself the
is severely reduced or stopped. This
occurs when one of the arteries that supply blood to the heart muscle
(coronary arteries) is blocked by an obstruction. The blockage is
sometimes from the buildup of plaque (deposits of
fat-like substances) due to atherosclerosis
A heart attack also can be caused by a
lodged in a coronary artery. Such an event is sometimes called a
or coronary occlusion
. A myocardial infarction is the damaging or
death of an area of the heart muscle resulting from a reduced blood
supply to that area.
If the blood supply is cut off severely or for
a long time, muscle cells suffer irreversible injury and die.
Disability or death can result, depending on how much heart muscle is
Sometimes a coronary artery temporarily
contracts or goes into spasm. When this happens the artery narrows
and blood flow to part of the heart muscle decreases or even stops.
What causes a spasm is unclear. But it can occur in normal-appearing
blood vessels as well as vessels partly blocked by atherosclerosis.
If a spasm is severe, a heart attack may result.
What is angina pectoris?
is the medical term for chest pain due to coronary heart disease. This is a condition in which the heart muscle doesnít receive enough blood, resulting in pain in the chest.
Angina is a symptom of a condition called myocardial ischemia
. It occurs when the heart muscle (myocardium) doesnít get as much blood (hence as much oxygen) as it needs for a given level of work. Insufficient blood supply is called ischemia.
When does angina pectoris occur?
Angina pectoris can occur when blood flow to the heart is enough for normal needs but not enough when the heartís needs increase. It may happen during physical exercise, strong emotions, or extreme temperatures. Running to catch a bus, for example, could trigger an attack of angina while walking to a bus stop might not. Some people, such as those with a coronary artery spasm, may have angina when theyíre resting. (See Prinzmetalís or variant angina pectoris below.)
Angina is a sign that someone is at risk of heart attack.
What is variant angina pectoris (Prinzmetalís angina)?
Variant angina pectoris
is also called Prinzmetalís angina. It differs from typical angina in that it occurs almost exclusively when a person is at rest, and it doesnít follow a period of physical exertion or emotional stress. Attacks can be very painful and usually occur between midnight and 8 a.m. Itís associated with
acute myocardial infarction (heart attack).
severe cardiac arrhythmias. These may include ventricular tachycardia
sudden cardiac death.
Variant angina is due to coronary artery spasm. About two-thirds of people with it have severe coronary atherosclerosis
in at least one major vessel. The spasm usually occurs very close to the obstruction.
Many people with Prinzmetalís angina go through an acute, active phase. Anginal and cardiac events may occur frequently for six months or more. During this time, nonfatal myocardial infarction occurs in up to 20 percent of patients; death occurs in up to 10 percent. People who develop serious heart rhythm disturbances (arrhythmias) at this time are at greater risk of sudden death.
Most people who survive an infarction or this initial three- to six-month period stabilize, and symptoms and cardiac events tend to diminish over time. Long-term survival is excellent, ranging from 89 to 97 percent at five years. Patients without significant obstructive coronary artery disease have an excellent long-term outlook.
The ergonovine test is the most sensitive and useful test for coronary spasm. In this it, the drug ergonovine is administered to induce coronary spasm. Hyperventilation and coronary injections of acetylcholine
are other means used to provoke variant angina.