Heart Health

A Glossary of Terms for Coronary Artery Disease

Coronary artery disease goes by different names and may be referred to as heart disease, coronary disease, coronary heart disease, or atherosclerotic heart disease. Some of the more important terms with which you should be familiar are provided below:

Angina The chest pain associated with blockage of the coronary artery is called angina; the full name is angina pectoris.

Atherosclerosis This is the process that causes the narrowing of blood vessels which can lead to blockage of the coronary artery. It involves the build-up of a yellowish substance, athersclerotic plaque, containing cholesterol and fat material. Atheresclerosis can develop in many different arteries in the body, resulting in different conditions, such as stroke and peripheral arterial disease. Like atherosclerosis in other areas of the body, the process in the heart that leads to the blockage of a coronary artery is complex and usually takes many years. A blockage that is more than 50% is considered significant and becomes critical when it is 90% or more. The blockage may be localized at a specific point in the artery or it may be diffuse, involving the entire length of the artery. The location of the blockage in an artery is also important; the further downstream the blockage in the artery, the less important the stoppage of blood becomes because there is less heart muscle to supply. These factors are important in determining the choice of treatment. For example, balloon angioplasty has the best results when damaged areas (lesions) are short in length and the artery is not completely blocked.

Coronary artery Coronary arteries are the blood vessels that bring the oxygen and nutrients carried by the blood to the heart muscle. I like to refer to them as the "plumbing" to my patients. Everyone has several coronary arteries, and they have names like left main coronary artery (left main), left anterior descending artery (LAD), diagonal artery (D), ramus intermedius (RI), circumflex artery (CIRC), obtuse marginal artery (OM), right coronary artery (RCA), posterior descending artery (PDA), and the posterior lateral artery (PL). These arteries are not equally important and can be different for each individual. The importance of one particular coronary artery is determined by how much of the heart's muscle depends on it for its blood supply. Sometimes when a coronary artery is blocked, new vessels will develop and reroute blood around the blockage, similar to a detour at a road construction site. This is called collateral circulation and is nature's own bypass operation.

Heart function How well a heart functions is important because it determines whether or not surgery will be needed. Doctors refer to heart function in terms of left ventricular ejection fraction (LVEF), which indicates how much blood is ejected from the heart with each contraction. A low ejection fraction indicates that the heart is not functioning properly:

Ejection Fraction	Heart Function
50% or more	Normal
40% to 49%	Mildly abnormal
30% to 39%	Moderately abnormal
29% or less	Severely abnormal

There are many tests to measure LVEF including such procedures as cardiac catheterization, echocardiogram, and nuclear scans of the heart.

Myocardial infarction Myocardial infarction is the term that physicians use for heart attack. A new onset of heart attack is called an "acute myocardial infarction." Besides heart attack, people sometimes refer to myocardial infarction as a "coronary." Angina and heart attack will be discussed in greater detail.