Atrial fibrillation. Reversion to normal sinus rhythm.

Auricular, or atrial fibrillation, is one of the most common cardiac arrhythmias. The mechanism of diagnosis will not be considered here, but rather the clinical criteria for attempted reversion to normal sinus rhythm. This report is concerned with the chronic type associated with severe organic heart or vascular disease, and in those persons previously considered bad risks. The treatment of atrial fibrifiation has been, and still is, a controversial subject. There is agreement that the ventricular rate should be controlled with digitalis. It also is agreed that the manifestations of the associated heart disease should be treated as indicated. However, the dispute arises over the question as to whether or not to allow patients to remain in atrial fibrillation. In the past, the general attitude has been conservative. Recently, some physicians have advised that no attempt at reversion be made because the fibrillation with a slow ventricular rate is practically as efficient as normal rhythm. Hecht, Osher, and Samuels1 showed that cardiac reserve during exercise is greatly improved on reversion of auricular fibrillation to normal sinus rhythm, but that it is not greatly changed at rest. Griggs, Hadley and Stevens2 called attention to the greater acceleration of the heart rate with moderate exertion in atrial fibrillation which decreased cardiac efficiency. Furthermore, the studies of Kory and Meneelr by cardiac catheterization have shown that persons with atrial fibrillation who have been compensated by all possible means except quinidine, have low resting and exercise cardiac output, but that after reversion to normal sinus rhythm the output is increased during rest and exercise. We believe that each patient must be considered individually, but in general, every patient should have the benefit of an attempt to return the atrial fibrillation to a normal sinus rhythm. Those opposed to this idea advance the argument that there is a great danger of mbo1isation with reversion as the atria are likely to detach portions of Intramural thrombi with the first forcible contractions, We feel that this danger Is more apparent than real because we have had many more episodes of embolisation occur in patients who remained In atrial fibrI1latIon,4 ‘urthermore, we cannot agree with the statement that atrlal fibrillation with a slow ventricular rate Is just as emcient as normal sinus rhythm, because congestive heart failure occurs earlier and more frequently in the former, It has been stated that no attempt to induce reversion should be made if atrial fibrillation has been present longer than a certain period time, This varies anywhere from two weeks to two years depending upon the authority quoted. We believe that the time interval is not