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glossary:heart_failure

Heart failure

Heart failure: Inability of the heart to keep up with the demands on it and, specifically, failure of the heart to pump blood with normal efficiency. When this occurs, the heart is unable to provide adequate blood flow to other organs such as the brain, liver and kidneys. Heart failure may be due to failure of the right or left or both ventricles. The signs and symptoms depend upon which side of the heart is failing. They can include shortness of breath (dyspnea), asthma due to the heart (cardiac asthma), pooling of blood (stasis) in the general body (systemic) circulation or in the liver's (portal) circulation, swelling (edema), blueness or duskiness (cyanosis), and enlargement (hypertrophy) of the heart.

There are many causes of congestive heart failure including: (1) coronary artery disease leading to heart attacks and heart muscle weakness, (2) primary heart muscle weakness from viral infections or toxins such as prolonged alcohol exposure, (3) heart valve disease causing heart muscle weakness due to too much leaking of blood or heart muscle stiffness from a blocked valve, and (4) hypertension (high blood pressure). Rarer causes include hyperthyroidism (high thyroid hormone), vitamin deficiency, and excess amphetamine (“speed”) use.

The aim of therapy is to improve the pumping function of the heart. General treatment includes salt restriction, diuretics (to get rid of excess fluid), digoxin (to strengthen the heart), and other medications. A drug called spironolactone has been found to be a major help in treating congestive heart failure Its beneficial effects are additive to those from ACE inhibitors, another class of drugs commonly relied on in treating heart failure. A pacemaker-like device is also now available to treat heart failure. The implantable device delivers synchronized electrical stimulation to three chambers of the heart, enabling the heart to pump blood more efficiently throughout the body.

Types of Heart Failure

acute congestive heart failure

Rapidly occurring cardiac output deficiency marked by venocapillary congestion, hypertension, and edema.

backward heart failure

A concept of heart failure emphasizing the causative contribution of passive engorgement of the systemic venous system, as a result of dysfunction in a ventricle and subsequent pressure increase behind it.

diastolic heart failure

Heart failure due to a defect in ventricular filling caused by an abnormality in diastolic function.

Diastolic Dysfunction: Inadequately treated high blood pressure is the most common cause of diastolic dysfunction. High blood pressure stresses the heart because the heart must pump blood more forcefully than normal to eject blood into the arteries against the higher pressure. Eventually, the heart's walls thicken (hypertrophy), then stiffen. The stiff heart does not fill quickly or adequately, so that with each contraction, the heart pumps less blood than it normally does. Diabetes causes other changes that stiffen the walls of the ventricle.

As people age, the heart's walls also tend to stiffen. The combination of high blood pressure and diabetes, which are common among older people, and age-related stiffening makes heart failure particularly common among older people.

forward heart failure

A concept of heart failure that emphasizes the inadequacy of cardiac output relative to body needs and considers venous distention as secondary.

high-output heart failure

That in which cardiac output remains high; associated with hyperthyroidism, anemia, arteriovenous fistulas, beriberi, osteitis deformans, or sepsis.

left-sided heart failure

Failure of adequate output by the left ventricle, marked by pulmonary congestion and edema.

left ventricular failure

Failure of adequate output by the left ventricle, marked by pulmonary congestion and edema.

low-output heart failure

That in which cardiac output is decreased, as in most forms of heart disease, leading to manifestations of impaired peripheral circulation and vasoconstriction.

right-sided heart failure

Failure of adequate output by the right ventricle, marked by venous engorgement, hepatic enlargement, and pitting edema.

right ventricular failure

Failure of adequate output by the right ventricle, marked by venous engorgement, hepatic enlargement, and pitting edema.

systolic heart failure

Heart failure due to a defect in the expulsion of blood that is caused by an abnormality in systolic function.

In systolic dysfunction, the heart contracts less forcefully and cannot pump out as much of the blood that is returned to it as it normally does. As a result, more blood remains in the lower chambers of the heart (ventricles). Blood then accumulates in the lungs, veins, or both.

Coronary artery disease is a common cause of systolic dysfunction. It can impair large areas of heart muscle because it reduces the flow of oxygen-rich blood to the heart muscle, which needs oxygen for normal contraction. Blockage of a coronary artery can cause a heart attack, which destroys an area of heart muscle. As a result, that area can no longer contract normally.

Other causes include: Myocarditis (inflammation of heart muscle), heart valve disorders, stenosis, pulmonary hypertension, pulmonary embolism, deficiency of red blood cells or hemoglobin (anemia)

glossary/heart_failure.txt · Last modified: 2012/10/16 14:40 (external edit)