Auricular flutter is a relatively infrequent disorder of the heart beat. It very rarely lasts more than a year or two and when it is prolonged it tends to change to auricular fibrillation or to terminate fatally. A remarkable exception that has come to our notice is the reason for the present report. A suggestion of the incidence of auricular flutter may be gained by a comparison of the figures of the electrocardiograms taken in the cardiographic laboratory of the Massachusetts General Hospital during the past thirteen years. These comprise records taken on cardiac patients in the house and outpatient departments, research tracings, and those taken on private patients of our own and of other physicians. Up to Dec. 3, 1927, 13,978 electrocardiograms had been taken on 8,600 patients. Auricular flutter has been recorded in only seventy-two patients. During this period, 947 cases showed auricular fibrillation. Auricular flutter is sometimes