Heart Failure

Heart failure is the inability of the heart to pump enough blood to sustain life. Put another way, heart failure is a significant drop in cardiac output.

Heart failure can be the result of many different heart diseases. Valve disorders can reduce the pumping efficiency of the heart enough to cause heart failure. Cardiomyopathy, or disease of the myocardial tissue, may reduce pumping effectiveness. A specific event, such as myocardial infarction, can result in myocardial damage that causes heart failure. Dysrhythmias, such as complete heart block or ventricular fibrillation, also can impair the pumping effectiveness of the heart and thus cause heart failure. Stress also can trigger temporary cardiomyopathy, often called stress cardiomyopathy or “broken heart syndrome.”

Failure of the right side of the heart, or right heart failure, accounts for about one-fourth of all cases of heart failure. Right heart failure often results from the progression of disease that begins in the left side of the heart. Failure of the left side of the heart results in reduced pumping of blood returning from the lungs. Blood backs up into the pulmonary circulation, then into the right heart—causing an increase in pressure that the right side of the heart simply cannot overcome. Right heart failure also can be caused by lung disorders that obstruct normal pulmonary blood flow and thus overload the right side of the heart—a condition called cor pulmonale.

Congestive heart failure (CHF), or simply left heart failure, is the inability of the left ventricle to pump blood effectively. Most often, such failure results from myocardial infarction caused by coronary artery disease. It is called congestive heart failure because it decreases pumping pressure in the systemic circulation, which in turn causes the body to retain fluids. Portions of the systemic circulation thus become congested with extra fluid. As stated above, left heart failure also causes congestion of blood in the pulmonary circulation, termed pulmonary edema—possibly leading to right heart failure.

Patients in danger of death because of heart failure may be candidates for heart transplants or heart implants. Heart transplants are surgical procedures in which healthy hearts from recently deceased donors replace the hearts of patients with heart disease. Unfortunately, a continuing problem with this procedure is the tendency of the body’s immune system to reject the new heart as a foreign tissue.