Anatomy of the Heart

The heart is a muscular organ composed of four chambers: two upper chambers called atria and two lower chambers called ventricles. These four chambers pump blood through the body in a rhythmic pattern with the help of the four valves in the heart. The movement of blood through the body can be felt at the wrist or neck and is known as the pulse.

Although the heart is full of blood, it cannot receive oxygen and nutrients from the blood inside the chambers. The heart muscle must rely on the arteries on the surface of the heart to nourish it and keep it working properly. These surface arteries are known as the coronary arteries. There are three main coronary arteries: the right coronary artery, the left anterior descending coronary artery and the circumflex coronary artery. These three arteries branch into thousands of small arteries like a tree trunk branches into limbs, bringing oxygen and nutrients to the heart muscle cells.

Coronary Artery Disease

Occasionally, these arteries become narrowed due to a build-up of fat, cholesterol and calcium and cannot carry enough oxygenated blood to the muscle.  This picture shows a constricted Left Anterior Descending (LAD) artery. This reduced flow of blood through the narrowing is a lot like what happens to the plumbing in our homes as the pipes become clogged with a build-up of mineral deposits - not as much water can flow. The term "coronary artery disease" refers to any abnormal condition of the coronary arteries that interferes with the delivery of an adequate supply of blood to the heart muscle. More than 95 percent of all coronary artery disease is due to atherosclerosis (cholesterol and calcium deposits).

When the heart muscle does not get enough oxygenated blood to meet its demands, it experiences a hunger for more oxygen. This hunger is felt by the patient as a  painful tightening, pressure, or fullness in the chest which we term "angina pectoris".  Total occlusion of a coronary artery leads to a heart attack (myocardial infarction). In order to treat coronary artery disease most effectively, we must have an accurate picture of the coronary arteries. The only way we can actually see these arteries is by injecting dye into them during a cardiac catherization. This procedure is called coronary angiography.

Cardiac catheterization is also useful in diagnosing other disorders of the heart such as defective heart valves, muscle disease and  other problems of the heart, lungs, and blood vessels.

Medical Procedures