Glycosides in the Treatment of Congestive Heart Failure

The most important and common drugs in the treatment of congestive heart failure are the cardiac glycosides, which may occur naturally in the body. 

When the heart can no longer pump an adequate supply of blood to meet the metabolic needs of the tissues or in relation to venous return, cardiac failure may ensue. The causes of cardiac failure are complex, but stem from mechanical abnormalities (e.g., pericardial tamponade), myocardial failure (e.g., cardiomyopathy and inflammation), and arrhythmias. In high-output failure, the cardiac output, which may be normal or even higher than normal, is not sufficient to meet the metabolic requirement of the body. Cardiac failure may predispose a patient to congestive heart failure, which is a state of circulatory congestion. Toxic injury, caused by agents such as doxorubicin, the alkaloid emetine in ipecac syrup, cocaine, or ethyl alcohol, is another way by which the functional integrity of the heart may also be compromised. 

A compensatory mechanism is initiated in the event of congestive heart failure. This consists of  

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