Sometimes the buildup is very gradual, but in other cases the buildup is suddenly increased as a chunk of matter breaks off and suddenly blocks the already narrowed opening. Certain factors seem to favor the buildup of these plaques. A strong family history of heart attacks is a definite risk factor, reflecting some metabolic derangement in either cholesterol handling or some other factor. Being male, for reasons probably related to the protective effects of some female hormones, is also a relative risk. Cigarette smoking and high blood pressure are definite risks, both reversible in most cases.
Risk also increases with age.
Medications are increasingly effective for symptom control, as well as prevention of complications. The oldest and most common agents are the nitrates, derivatives of nitroglycerine. They include nitroglycerine, isosorbide, and similar agents. Newer forms include long acting oral agents, plus skin patches which release a small amount through the skin into the bloodstream over a full day. They act by reducing the burden of blood returning to the heart from the veins and also by dilating the coronary arteries themselves.