Heart Diseases

Cardiovascular Disease

Cardiovascular disease—disease of the heart or blood vessels—can develop in any part of the circulatory system. Problems can occur with the valves, the sinoatrial node, the heart muscle, or the blood vessels.

Arteriosclerosis

commonly called hardening of the arteries, includes a variety of conditions in which artery walls thicken and lose elasticity. There is evidence that heredity and a high cholesterol level in the blood can lead to atherosclerosis, the most common form of arteriosclerosis. (See also Cholesterol; Food and Nutrition, “Fats and Oils.”)

Hypertension.

The force of the blood being pumped through the arteries exerts pressure on the arterial walls. When this pressure is too high it is an unhealthy condition called hypertension, or, simply, high blood pressure. If left untreated, it can lead to heart attack, stroke, kidney disease, or other illnesses.

Rheumatic fever

causes inflammation of the body tissues, joints, and heart. All heart tissues, including the pericardium, can be affected, but the heart's valves are most often damaged. Antibiotics can lessen the adverse effects and prevent serious heart damage.

Bacterial endocarditis

a bacterial infection of the inner lining of the heart muscle, leads to inflammation of the lining. More than half of the incidents of bacterial endocarditis are a result of rheumatic fever. Bacteria may also be introduced into the bloodstream during minor medical procedures, but this is rare.
Congenital heart disease

is heart disease present at birth. It ranges from minor heart murmurs that require no treatment to fatal structural defects.

Fibrillation.

In a normal, healthy heart the muscles contract and relax in an orderly manner. This rhythmic pulsing can be disturbed, however, by faulty electrical impulses that cause the heart to beat abnormally or irregularly. Ventricular fibrillation—rapid, uncoordinated contractions of the heart—is one of the most serious disturbances of heart rate and rhythm and can lead to cardiac arrest and death. Other rhythm disorders, or arrythmias, include auricular fibrillation and flutter, tachycardia (rapid heartbeat), and bradycardia (slow heartbeat).

Congestive heart failure

occurs when engorgement of the veins serving the lungs or of those serving the rest of the body prevents the heart muscle from being able to pump forcefully enough to deliver an adequate supply of blood to the body. It can be caused by disease of either the heart muscle or the valves.

Heart attack

occurs when the flow of blood to the heart muscle itself is cut off or so severely impeded as to cause destruction of cardiac tissue. It is a life-threatening episode of heart disease and can result from a blood clot or advanced atherosclerosis in the coronary arteries.

Diagnosis and Treatment

A physician can detect many heart conditions before symptoms become apparent by using an instrument called an electrocardiograph, for example. It detects tiny electrical impulses from the contracting heart and records them on an electrocardiogram, or EKG or ECG. Normal hearts produce characteristic peak-and-valley tracings. These reflect the contractions of the auricles and ventricles. A tracing that varies from this pattern may indicate a disorder.

Heart conditions can also be diagnosed with the aid of various types of X rays, including X-ray films and fluoroscopy, which enable physicians to see the heart in action. More detailed examinations can be made using such techniques as angiocardiography, which tracks the passage of blood through the heart, coronary arteries, and larger vessels; computed tomography (CT), which provides a detailed cross-sectional image of the heart; and magnetic resonance imaging (MRI), which can show images of the heart in many planes.

Treatment of heart conditions may be possible with prescribed drugs that improve blood flow, reduce blood pressure, prevent blood clots from forming or enlarging, increase the heart's pumping ability, or regulate the heartbeat. Frequently prescribed drugs include anticoagulants that prevent unwanted clotting and vasodilators that widen the blood vessels.

Other treatments include pacemaker implantation and cardiac catheterization. A pacemaker is an electronic device that produces rhythmic electrical impulses to regulate the patient's heartbeat. In the process known as cardiac catheterization, physicians insert a catheter, or thin plastic tube, through an artery in the arm or leg to reach the coronary arteries. They then inject special enzymes through the tube to dissolve arterial blood clots. In some cases physicians use a small balloon on the end of the catheter. The balloon is inflated slightly in a narrowed artery to widen it.

Coronary bypass surgery may be necessary to provide a new path for blood flow around a blocked artery. In the most radical surgery the patient may undergo a heart transplant, in which the diseased heart is replaced with a healthy heart from a deceased donor.

Most physicians recommend changes or improvements in personal habits as the best way of avoiding the early onset of some types of heart disease. Some preventive measures include controlling obesity, hypertension, blood cholesterol levels, and diabetes; avoiding smoking; and fostering healthful habits such as good nutrition, exercise, stress management, and regular medical examinations.