Digitalis and diuretics: still the standard therapy?

Although digitalis preparations are effective in controlling the ventricular rate in atrial fibrillation and certain other supraventricular tachyarrhythmias, with consequent haemodynamic benefit, there is increasing controversy about significant sustained inotropic efficacy in patients in sinus rhythm. Digoxin toxicity is a serious hazard and subtherapeutic dosing a deception and waste of resources; blood levels are the key to optimum dosing. A considered withdrawal of the drug and reintroduction if haemodynamic deterioration ensues is probably the only way of proving in an individual patient if the drug is really worth using long-term. Diuretics have had a major place in management of cardiac failure, correcting the fluid overload. However there are a number of troublesome metabolic and other consequences, and excessive diuresis can be dangerous. Vasodilator therapy has recently had a major impact on management of more severe forms of cardiac failure, usually with coadministration of diuretics, but the predominant pattern of drug use in milder heart failure is to rely primarily or even exclusively on diuretics. Rational use of drugs in cardiac failure would be greatly facilitated by availability of simple non-invasive techniques to measure cardiac function and filling pressures. Until this becomes possible it will be difficult to alter the traditional pattern of long-term use of digoxin and diuretics whenever there have been symptoms attributable to heart failure.