The occurrence of paroxysmal tachycardia in infancy and in childhood is extremely rare, and few authentic cases have been recorded in medical literature. The youngest patient in a reported case was an infant, aged 4 days, whose case was reported by Werley.1 The type of tachycardia was not identified because electrocardiograms were not taken, but polygraphic tracings showed the rate of the heart to be 307 a minute. Necropsy revealed a widely patent foramen ovale; distinctive microscopic changes were not evident.Colgate and McCulloch2 reported two cases of paroxysmal tachycardia in infancy; one occurred in a child, aged 21 days, and the other in a child, aged 24 days. In the first case the rate of the heart was 250 during a paroxysm, but since electrocardiograms were not obtained, the type of tachycardia was not determined. In the second case, electrocardiograms revealed changes that the authors concluded were paroxysms of auricular tachycardia; the rate was 291. The children in both cases recovered.A case of paroxysmal auricular flutter with a 1: 1 rhythm was observed by Lewis 3 in an infant aged 3 months. The rate varied from 270 to 290 a minute. The course of the disease was not reported. A case of auricular flutter with 2: 1 rhythm, and paroxysms in which the rate was 1:1, was seen by Poynton and Wyllie 4 in a male infant aged 4 months. The heart was enlarged, but the cause of the car-