Paroxysmal supraventricular tachycardia in infancy. Report of a case treated with methacholine.

Abstract

Digitalis is usually so successful in the conversion of paroxysmal supraventricular tachycardia to normal sinus rhythm in infants that experience with other drugs is infrequently obtained. On rare occasions both digitalis and the subsequent administration of quinidine are ineffective. Not uncommonly so much time has then elapsed that the clinical condition has become critical, and thus need for rapid-acting parasympathomimetic drugs becomes imperative. Because of the infrequent necessity for its use and perhaps also because of its condemnation by several authorities, 1,2 experience with methacholine (Mecholyl) has been limited. Successful utilization in infancy has been recorded in only 7 previous cases 3,4 ; for this reason the following report is presented. Report of a Case A 6-month-old white female was admitted to Montefiore Hospital from another institution on Feb. 24, 1961, because of severe congestive heart failure and a respiratory infection. The weight was 4.8 kg. The characteristic thrills and machinery