[Spontaneous recovery of sinus rhythm in long-standing mitral fibrillation]

The case of a 73-year-old woman with a 10 year history of mitral valvulopathy in atrial fibrillation is reported. On two occasions spontaneous recovery of sinus rhythm occurred. The first, lasting about 48 hours, followed acute digitalis poisoning. On the second occasion there was a slight intermittent 1st degree A-V blockage, though no glucoside had been taken for about 5 months.