Glossary

Anemia:

A deficiency in the oxygen-carrying material of the blood.

Aneurysm:

A pathological blood-filled dilatation of a blood vessel.

Angina pectoris:

Chest pain caused by insufficient blood flow to the heart muscle.

Aortic:

Relating to the aorta, which is the major vessel that carries oxygenated blood from the heart to the body. Sometimes this term is used to denote the aortic valve, which is the valve that prevents back-flow of blood from the aorta into the left ventricle. (For example, "aortic stenosis.")

Arrhythmia:

Irregular heartbeat.

Artery:

A vessel that carries blood away from the heart. Arteries generally carry oxygenated blood. In mammals, the exception is the pulmonary artery, which carries deoxygenated blood to the lungs.

Atherosclerosis:

An accumulation of fat-containing deposits on arterial walls.

Atrium:

The chamber of the heart that collects blood returning from the rest of the body. In all vertebrates but fish, there are two atria, left and right. The right atrium collects deoxygenated blood from the body and passes it to the right ventricle. The left atrium collects oxygenated blood from the lungs and passes it to the left ventricle.

Bradycardia:

Excessively slow heartbeat.

Cardiomyopathy:

This is the general term for diseases of the heart muscle. The most common of these diseases is the dilated cardiomyopathy in which the disease weakens the heart muscle and causes left ventricular dilation leading to increased diastolic pressure and volume.

Coronary:

Relating to the heart, or to one of the two arteries that originate in the aorta and supply blood directly to heart tissue.

Cyanosis:

A condition in which a person's skin is discolored to a bluish hue because of inadequate oxygenation of the blood.

Diastole:

Normal period of relaxation and dilatation of the heart cavities.

Dilatation:

The condition of being abnormally dilated or enlarged.

Dyspnea:

Difficulty in breathing.

Hypertension:

A condition in which a person's blood pressure is abnormally high. For normal adults, the pressure should be less than 130 mmHg systolic and less than 85 mmHg diastolic. Pressures above 140/90 indicate a mild form of hypertension; above 180/110 is considered severe.

Insufficiency:

Describes a condition in which a valve is not able to prevent back-flow of blood. The resulting back-flow is termed a regurgitation.

Ischemia:

Localized loss of blood supply due to a mechanical obstruction.

Mitral Valve:

Valve that separates the left atrium and the left ventricle and prevents back-flow from the ventricle to the atrium. Derived from "miter," which it resembles. (A miter is a tall, pointed hat with peaks in front and back which is worn by a bishop.)

Pulmonary:

Relating to the lungs. Sometimes this term is used to denote the pulmonary valve, which is the valve that prevents back-flow of blood from the pulmonary artery into the right ventricle. (For example, "pulmonary regurgitation.")

Prolapse:

Floppy valve, associated with regurgitation.

Regurgitation:

Back-flow of blood through an insufficient valve. (For example, mitral valve regurgitation.)

Stenosis:

Constriction of a passage. Used typically when there is a narrowing of a valve opening (for example, mitral valve stenosis) or of a blood vessel.

Syncope:

A brief loss of consciousness caused by temporary lack of oxygenated blood.

Systole:

Period of contraction of the heart during which blood is ejected from the ventricles.

Tachycardia:

Excessively rapid heartbeat.

Tricuspid Valve:

Valve that separates the right atrium and the right ventricle and prevents back-flow from the ventricle to the atrium. It is composed of three leaf-like parts.

Vein:

A vessel that carries blood toward the heart.

Ventricle:

The chamber of the heart that is responsible for pumping blood out to the rest of the body. In mammals and birds, there are two ventricles, left and right. The right ventricle pumps deoxygenated blood to the lungs via the pulmonary artery; the left ventricle pumps oxygenated blood to the body via the aorta.