CONGESTIVE HEART FAILURE
In the strictest medical terms, this entity is a very complex group of findings and events caused by a large number of diseases of the heart. In the interests of clarity, this discussion will focus primarily on the routine and common aspects of congestive heart failure. Heart failure is NOT the same as a heart attack.
In essence, heart failure refers to states where the heart muscle is unable to pump sufficient amounts of blood through the body to meet its needs. In thinking of the heart's pumping action it is convenient to consider the right and left sides separately, each having an upper and lower chamber, the atrium and the ventricle.
Failure of the left venricle, for causes discussed later, results in inadequate circulation to the aorta and thus to the rest of the body. The primary resulting symptoms are marked fatigue, weakness, confusion, and ultimately stroke, cardiac arrest or severe drops in blood pressure leading to death. The symptoms of right heart failure, on the other hand are related to backing up or "damming" of the blood returning to the heart from the veins of the body, as the right ventricle fails to clear out the returning blood as quickly as it accumulates. This results in accumulation of fluid in the legs, or even in the entire body, referred to as edema.
When both sides of the heart fail together (a very common occurrence), there is often a condition called pulmonary edema. This is a filling of the lungs with fluid which was not adequately removed from the lungs by the left ventricle, and which was already present in excessive amounts as a result of edema from right sided failure. If it occurs rapidly, pulmonary edema can result from "pure" left sided failure alone. The symptoms in either case are profound shortness of breath, cough, and debility.
A few presentations are highly typical of heart failure. These include sudden nighttime episodes of suffocating breathlessness, which awaken the patient; the effects of gravity pooling increased amounts of fluid in the chest of the marginally compensated heart are responsible. This is called paroxysmal nocturnal dyspnea. Orthopnea is also common, referring to any breathlessness worse when lying down.
The typical patient presents with any combination of the symptoms mentioned above, accompanied by characteristic changes in the sound of the heart through the stethoscope. Confirmatory tests include ultrasound images of the ventricles beating, special x- rays, and sometimes catheterization of the heart.
What can cause heart failure? Most common is the longstanding burden imposed by years of high blood pressure. Eventually the heart muscle just tires out. Sometimes, the heart muscle is
so damaged by a heart attack or attacks, that the surviving areas are just inadequate to prevent failure. Yet another cause is damage to one of the heart valves from rheumatic fever, congenital defects, or infection causing obstruction to the flow of blood, or lack of backwash of blood during contractions. Viral infections can occasionally damage the heart so
severely that permanent heart failure results. The list is enormously long, but the resulting syndromes are similar.
The physician approaches the disease by first looking for reversible underlying causes-- valves that can be surgically replaced, infections to be treated, etc. If no such factors are identified, three approaches are taken medically. The first is to give diuretics, or water pills. By forcing the kidneys to excrete extra water (and by restricting salt intake), the load on the circulation can be reduced as there is less fluid to be pushed around the circulation. Edema is also reduced. Secondly, some drugs such as digoxin actually increase the force of the pumping action of the heart. In recent months, the role of digitalis has been questioned, as many patients do not benefit greatly, and side effects are common. Finally, one can give drugs which dilate and relax the blood vessels. This reduces the resistance against which the heart must pump, and also reduces the amount of blood being squeezed back to the heart by the venous system. Examples of such drugs are prazosin, captopril and certain forms of nitroglycerine. Combinations of drugs are common, and close supervision by an experienced internist, cardiologist or other qualified doctor is crucial. In severe situations, these and other drugs must be given by vein, with intensive care observation.
Prevention is largely limited to measures to treat high blood pressure and prevent coronary disease. Once present, the usual type of heart failure can often be controlled with medications for long periods, though extreme variability is commonplace. Early detection and treatment of setbacks is important, and the patient must promptly report any marked weight gain, new breathing symptoms, swelling, or fatigue promptly. Ultimately, pulmonary edema or blood pressure collapse is the cause of death in those succumbing to the disease.
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