224 Ivabradine, a Safe and Effective Monotherapy in the Treatment of Congenital Junctional Tachycardia in Infancy

Abstract

Background: Congenital junctional ectopic tachycardia (JET) is a rare, drug resistant, incessant tachycardia with high morbidity and mortality in infancy [1,2]. Ivabradine, a new generation antiarrhythmic agent acting as a cardiac cell pacemaker inhibitor, has been effective both as a sole agent and as an adjuvant therapy with other older generation antiarrhythmics in controlling congenital junctional tachycardia (JET) as per a number of case reports [3,4]. Case: We report a case of a term infant born via emergency cesarean section secondary to foetal tachycardia with post-delivery ECG showing narrow complex tachycardia and evidence of atrioventricular dissociation confirming congenital JET with the initial echocardiogram revealing normal cardiac structure and function. Amiodarone, started once the infant reached our tertiary Centre, failed to achieve rate control. Subsequently, Flecainide was added at 48 hours of life, the infant remained in fast JET and developed haemodynamic instability requiring ventilation and inotropic support, with echocardiographic evidence of cardiomyopathy. Amiodarone was ceased and Ivabradine was then introduced at 0.1 mg/kg/day in two divided doses, following the second dose, rate control was successfully achieved and the cardiomyopathy resolved. The infant reverted to sinus rhythm a few hours after the second dose of Ivabradine and Flecainide was withdrawn successfully. The infant was discharged on monotherapy and remained in sinus rhythm upon follow-up at three months of age. Conclusion: JET in this case with resistance to Amiodarone and Flecainide would have most likely resulted in escalation of cardiac support. Ivabradine appears to have been safe and effective in this infant.L20085024942020-12-09 <br />