Paroxysmal tachycardia in infancy was first described by Buckland1 in 1892. Since then, there have been numerous reports of its occurrence; several of these cases were in newborn infants.2 However, the present case is unique in that it appears to represent the third reported instance of paroxysmal supraventricular tachycardia other than atrial flutter in which the onset of the ectopic rhythm occurred in utero. We have preferred the more conventional restrictive classification of paroxysmal tachycardia of supraventricular origin to include only atrial, AV nodal, and (the theoretical sinus) paroxysmal tachycardias (P. D. White3 and Katz4); thus paroxysmal atrial flutter and paroxysmal atrial fibrillation are considered a distinct and second category of rapid heart action. The first case was reported by Garvin and Kline5 in 1947; the pacemaker in their patient was in the AV node and the heart rate was 200 to 250 per minute.
Wilburne M, Mack EG. PAROXYSMAL TACHYCARDIA IN THE NEWBORN WITH ONSET IN UTERO. JAMA. 1954;154(16):1337-1338. doi:10.1001/jama.1954.02940500017006