Ivabradine is an effective antiarrhythmic therapy for congenital junctional ectopic tachycardia‐induced cardiomyopathy during infancy: Case studies

Abstract

Junctional ectopic tachycardia (JET) is a rare form of arrhythmia that is most commonly seen during infancy. JET is continuous and incessant, characterized by persistently high heart rates that may result in impaired cardiac function and tachycardia-induced cardiomyopathy. Despite the availability of multiple antiarrhythmic treatments, including flecainide and amiodarone, management of JET is generally very difficult. Catheter ablation has a high risk of atrioventricular block and it may require the placement of a pacemaker. Ivabradine, also known as a cardiac pacemaker cell inhibitor, is a new-generation antiarrhythmic used to treat sinus tachycardia and angina pectoris in adult patients. In this article, we present three cases of subjects with infantile congenital JET who were admitted to our clinic with a tachycardia-induced cardiomyopathy. The age of the subjects ranged from 52 days to 10 months. Although the cases of tachycardia could not be controlled by multiple antiarrhythmics, including a combination of amiodarone and flecainide combined with either propranolol or digoxin, they were rapidly converted into sinus rhythm with an ivabradine treatment of 0.1-0.2 mg/kg/day. No cardiac or other side effects were observed during ivabradine treatment, and left ventricular functions and rhythms improved within 24 hours. These three cases therefore provide hope that ivabradine may be a suitable standard initial treatment for congenital JET. However, additional research is needed to confirm the validity of these results in other circumstances.

Ivabradine use as an antiarrhythmic therapy in congenital junctional ectopic tachycardias

“…In this study, we presented successful management of congenital junctional ectopic tachycardia (JET)‐induced cardiomyopathy by ivabradine in three cases. Since there is a limited experience on ivabradine use in congenital JET, we wish to address this issue that merits more attention …”

“…Since there is a limited experience on ivabradine use in congenital JET, we wish to address this issue that merits more attention. 1 Ivabradine is a cardiac pacemaker cell inhibitor which is known as an I f channel. I f channel has a crucial physiological role in setting the heart rate and sensing its autonomic control.…”

Beneficial effects of ivabradine in atrial or ventricular arrhythmias

“…We read with interest the case report recently published by Ergul et al. concerning ivabradine use as an antiarrhythmic therapy in congenital junctional ectopic tachycardias . Although it is a novel concept, we wish to address some points that merit more attention.…”

“…In this context, successful management of congenital junctional ectopic tachycardia‐induced cardiomyopathy by ivabradine in three infants were very promising which supports the role of I f expression in ectopic automaticity. Furthermore, this work may widen a new clinical research avenue.…”

“…On the other hand, the authors’ statement in the discussion that ivabradine is used in adults to reduce the heart rate in atrial fibrillation should be revised because the I f current is mainly expressed in the sinus node and large trials just designed to detect the reduction of heart rate in patients with sinus rhythm. Hence, ivabradine use was exactly restricted to patients in sinus rhythm.…”