Intermittent Auricular Fibrillation

It has become recognized during the last few years that paroxysmal auricular fibrillation is a relatively common disorder, although probably not so frequent as chronic fibrillation. According to the published descriptions of cases, it would appear that the paroxysms usually last hours or days; nevertheless, all clinicians of experience must occasionally have encountered paroxysms lasting only a few minutes, particularly in cases of hyperthyroidism but also occasionally in other forms of cardiac involvement. Very brief paroxysms, not more than a few seconds in duration, have been very rarely observed. This may be due in part to the impossibility of recognizing the nature of such brief paroxysms by ordinary clinical methods and to the fact that unless they recur frequently they are recorded in electrocardiograms by mere chance. A careful search of the literature extending over the period of use of the electrocardiograph in clinical medicine for examples of such fleeting