The treatment of atrial fibrillation.

Much can be done for the patient with atrial fibrillation. In general, therapy is safe, effective, and at its best when the arrhythmia is not regarded as an entity unto itself. Atrial fibrillation does not usually occur de novo. When it is found in the absence of any disease, it is often an incidental discovery and usually a well-tolerated condition that needs no treatment. Indeed, in such instances, it may be the therapy rather than the arrhythmia that produces the difficulty. Atrial fibrillation is commonly found in the presence of other diseases; thus its treatment is predicated on the nature of the accompanying disease and its effect on the heart. There may be acute precipitating factors--such as an acute myocardial infarction, alcohol abuse, thyrotoxicosis, or circulatory congestion--control or relief of which could result in the disappearance of the atrial fibrillation. There may be electrolyte or volume depletion, which, if corrected, may also be followed by disappearance of atrial fibrillation. When atrial fibrillation is acute, there is an excellent chance that it will disappear spontaneously. Therefore, if a drug is employed in such a situation, it is best to employ one with a proven record, with the likelihood of benefit, and with few or no adverse effects. For this reason, it is best to begin with digoxin given orally to reduce the ventricular rate, except in atrial fibrillation associated with the WPW syndrome, for which digoxin is contraindicated and intravenous procainamide preferred. There is no advantage in adding other drugs to digoxin to help reduce ventricular rate, at least under initial conditions. There is also no need to consider restoration of sinus rhythm, because it can occur spontaneously, possibly abetted by digoxin. Moreover, chemical conversion, if done immediately, is accompanied by adverse effects and offers less chance of benefit than if done after stabilization. Certainly, if there is hemodynamic deterioration, direct-current cardioversion should be performed and will usually be effective and well tolerated. With chronic atrial fibrillation, the drug of choice is digoxin; helpful adjuncts are calcium blockers and beta-blockers.(ABSTRACT TRUNCATED AT 400 WORDS)