Ivabradine as an Adjunct for Refractory Junctional Ectopic Tachycardia Following Pediatric Cardiac Surgery: A Preliminary Study

Abstract

Objectives: Junctional ectopic tachycardia (JET) is a relatively common narrow complex rhythm typically characterized by atrioventricular dissociation or retrograde atrial conduction in a 1:1 pattern. Junctional ectopic tachycardia can be a life-threatening disorder, causing severe hemodynamic compromise and increased morbidity and mortality. The treatment of refractory JET can be very difficult, even with multimodal therapeutic interventions. The purpose of this study was to assess the role of ivabradine in cases of JET refractory to amiodarone and esmolol. Methods: A total of 480 congenital heart surgeries were carried out at our center in 2017. Twenty (4.16%) patients had postoperative JET. Among these, five infants, aged 7 to 12 months (median: 8 months), had refractory JET. These patients (three tetralogy of Fallot, one ventricular septal defect, one complete atrioventricular septal defect) were treated with oral ivabradine in the dose range of 0.1 to 0.2 mg/kg/12 h as an adjunct to amiodarone. Results: All five patients achieved rate reduction and eventual conversion to sinus rhythm. Mean duration to achieve heart rate of <140 bpm after initiation of ivabradine therapy was 16.8 hours (±7.2 hours), while mean duration to achieve sinus rhythm was 31.6 hours (±13.6 hours). No patient had any recurrence of JET. No patient exhibited any hemodynamic derangement nor side effects attributable to oral ivabradine. Conclusion: Oral ivabradine has the potential to be used as an adjunct to amiodarone in the treatment of JET in infants after surgery for congenital heart disease.

Ivabradine: A Potential Therapeutic for Children With Refractory SVT

“…In fact, the study is limited by (1) the small number of patients, (2) the short duration of follow-up, and (3) the lack of adequate assessment of ivabradine efficacy since it wasn't used as a single treatment in any of the patients. Furthermore, two retrospective studies, published in 2019, have tackled the use of ivabradine in treating post-operative pediatric JET (27,28). First, Krishna et al reported an adequate response to ivabradine in a cohort of eight patients with JET acquired after open-heart surgery.…”

“…Furthermore, two retrospective studies, published in 2019, have tackled the use of ivabradine in treating post-operative pediatric JET ( 27 , 28 ). First, Krishna et al reported an adequate response to ivabradine in a cohort of eight patients with JET acquired after open-heart surgery.…”

“…Second, Kumar et al conducted a retrospective review of the charts of congenital heart disease patients admitted for cardiac surgery over 1 year. Only 20 patients (of 480) had acquired JET post-operatively, five of them had refractory JET and were adequately treated with ivabradine and amiodarone ( 28 ). Together, Krishna et al and Kumar et al supported the use of ivabradine, as a single or adjunctive therapy, in treating refractory post-operative JET.…”

Diagnosis and management of junctional ectopic tachycardia in children

“…Thelatest tool in the armamentarium is ivabradine. [ 83 84 85 ] Ivabradine is recommended for select adults with chronic stable angina, heart failure, and inappropriate sinus tachycardia. Ivabradine acts through HCN channels which may play an important role in etiopathogenesis.…”

“…[ 86 ] In small case series, ivabradine has been found to be effective as an adjunct to amiodarone and as the sole agent. [ 83 84 85 ] Rate control is the initial response, followed by conversion to sinus rhythm. [ 84 ] Early administration before hemodynamic compromise ensues will be key as absorption will be affected once cardiac output is compromised.…”