What is Cardiovascular Disease?
Cardiovascular or heart disease is the leading cause of death and a common cause of morbidity in the United States. Coronary heart disease (CHD) and ischemic heart disease are more specific names for the principal forms of heart disease. These terms are used when there are clinical symptoms, such as angina, from coronary atherosclerosis or narrowing of the arteries.
The term coronary artery disease (CAD) is used when there is atherosclerosis in the coronary arteries (arteries that feed the heart muscle) but not symptoms. Atherosclerosis in the coronary arteries is the underlying cause of heart attacks, CHD and CAD. Angina pectoris occurs when atherosclerosis causes reduced blood flow and, therefore too little oxygen, to the heart muscle resulting in chest pain.
A myocardial infarction or heart attack occurs when a coronary artery becomes blocked, usually by a blood clot (thrombus), resulting in lack of blood flow to the heart muscle. The part of the heart muscle deprived of oxygen and other nutrients then dies or infarcts. About 1.1 million people in the United States experience a heart attack each year. Nearly 500,000 Americans die from CHD a year with more than half of these deaths occurring outside the hospital, within 1 hour of symptom onset.