The coronary arteries are small blood vessels that serve the needs of cardiac muscle. When coronary arteries become occluded to any degree, coronary heart disease (CHD) is present. Although CHD develops slowly over a period of years, a heart attack (myocardial infarction) can develop quite suddenly. Most heart attacks occur when a blood clot forms in a coronary artery already narrowed by plaque. Then the portion of the heart deprived of oxygen and nutrients dies, and surrounding tissue may also be damaged.
The following factors increase the risk of CHD:
- Male gender or postmenopausal female Family history of heart attack under age 55
- Tobacco usage (for example, smoking cigarettes, chewing tobacco)
- Severe obesity (30% or more overweight) Hypertension (high blood pressure)
- Unfavorable blood levels of HDL and LDL cholesterol
- Impaired circulation to the brain or the legs
- Diabetes mellitus
Hypertension (high blood pressure) is a major factor in the development of cardiovascular disease, and two controllable behaviors contribute to it: smoking cigarettes (including filtered cigarettes) and obesity. While cigarette smoking is a
habit to avoid, most of its detrimental side effects can be reversed when the individual stops smoking. Since obese individuals find it very difficult to lose weight, weight control should be a lifelong endeavor.
Investigators have identified several behaviors that may help to reduce the possibility of heart attack and stroke. Exercise is critical. Sedentary individuals have a risk of cardiovascular disease that is about double that of those who are very active. One physician recommends that his patients walk for one hour, three times a week. Stress reduction is also desirable for heart attack and stroke prevention. Daily meditation and yogali stretching and breathing exercises may help reduce stress.
A diet low in saturated fats and cholesterol retards plaque development and thereby helps reduce the chance of heart attack. Cholesterol is carried in the blood by two types of plasma proteins:
LDL (low-density, or "bad," lipoprotein) transports cholesterol to the tissues from the liver.
HDL (high-density, or "good," lipoprotein) transports cholesterol out of the tissues to the liver.
A diet low in saturated fat and cholesterol will probably lower the total blood cholesterol level and perhaps the LDL level of some individuals, but most likely will not raise the HDL level. Certain drugs apparently can raise the HDL level, and exercise is also sometimes effective.
Some of the cardiovascular risk factors, such as male gender and family history, are inherent in an individual. Other risk factors, however, can be controlled if the individual believes it is worth the effort. The four great admonitions for a healthy life-eating a low-fat, low-cholesterol diet; getting regular exercise; maintaining proper weight; and refraining from smoking-all contribute to keeping the blood cholesterol level low and the blood pressure within a normal range.
