When the coronaries are obstructed by blood clots or fatty deposits from arteriosclerosis, a myocardial infarction or heart attack occurs. If a blood clot partially blocks the main artery, the attack is not fatal and the individual survives with some degree of damage to the heart. Complete obstruction instead leads to death.
Symptoms can occur at any time. The most frequent disorder is unbearable pain that usually begins in the lower part of the chest or in the upper part of the abdomen. Pain often spreads to the neck and shoulders, down the arms, especially on the left side, and possibly to the back.
The conditions that increase the risk of a heart attack are lack of exercise, smoking, obesity, diabetes, prolonged high blood pressure, excess salt in the diet, family predisposition to heart attacks, prolonged emotional stress.
Dietary measures that reduce the risk of heart attacks are balanced caloric intake to maintain or achieve normal weight and use of unsaturated rather than saturated fats to help prevent further production of fatty deposits lining the blood vessels.