Coronary Heart Disease Learning Center

For people with coronary artery disease (CAD) and their loved ones, the possibility of a heart attack is a real and seemingly constant threat. CAD, sometimes called coronary heart disease (CHD), is the most common kind of heart disease in the United States and throughout Europe. It's also the leading cause of death in the United States.

What is CAD? Like any other organ or muscle, the heart must receive an adequate, dependable supply of blood in order to carry out its work. Oxygen- and glucose-rich blood is delivered to the heart by the coronary arteries. The four primary coronary arteries are located on the surface of the heart:

• right main coronary artery
• left main coronary artery
• circumflex artery
• left anterior descending artery

CAD occurs when one or more of the coronary arteries begin to harden and narrow due to the build-up of cholesterol and plaque. If one of these arteries becomes blocked and blood can no longer flow through it, the result is a heart attack, or myocardial infarction (MI).