Ectopic Atrial Tachycardia in a 12-Month-Old Girl Treated With Ivabradine and Beta-Blocker, a Case Report

Incessant Atrial Tachycardia From the Left Atrial Appendage Treated With Appendage Ligation

A previously healthy man presented in shock due to incessant tachycardia. He ultimately required extracorporeal membrane oxygenation for support and clipping of his appendage for arrhythmia control. This case highlights the importance of early recognition of cardiogenic shock, aggressive hemodynamic support, and a multidisciplinary approach to managing these challenging arrhythmias.

Ivabradine in a 15-day-old male neonate with refractory focal atrial tachycardia

Ivabradine is used to reduce heart rate in children with chronic heart failure and dilated cardiomyopathy, it has recently been used off-label to treat tachyarrhythmias such as ectopic atrial tachycardia and junctional ectopic tachycardia (JET) in children. We report a successful ivabradine experience in a male neonate with refractory focal atrial tachycardia (FAT).

Ivabradine monotherapy in pediatric patients with focal atrial tachycardia: a single-center study

This study investigated the efficacy of ivabradine monotherapy in pediatric patients with focal atrial tachycardia (FAT). We prospectively enrolled 12 pediatric patients (7.5 ± 4.5 years; six girls) with FAT who were resistant to conventional antiarrhythmics and received ivabradine as monotherapy. Patients were classified as having tachycardia-induced cardiomyopathy (TIC) if they had a left ventricular ejection fraction (LVEF) of < 50% and a left ventricular end-diastolic dimension (LVDD) z-score of > 2 due to tachycardia. Oral ivabradine was initiated at 0.1 mg/kg every 12 h, increased to 0.2 mg/kg every 12 h if no restoration of stable sinus rhythm was observed after two doses, and discontinued after 48 h if neither rhythm nor heart rate control was observed. Of these patients, six (50%) had incessant atrial tachycardia, and 6 had frequent short episodes of FAT. Six patients were diagnosed with TIC, and their mean LVEF and mean LVDD z-score were 36.2 ± 8.7% (range, 27-48%) and 4.2 ± 1.7 (range, 2.2-7.3), respectively. Finally, six patients achieved either rhythm (n = 3) or heart rate control (n = 3) within 48 h of ivabradine monotherapy. One patient achieved rhythm/heart rate control with ivabradine at a dose of 0.1 mg/kg every 12 h, while the others achieved rhythm/heart rate control at a dose of 0.2 mg/kg every 12 h. Five patients received ivabradine monotherapy for chronic therapy, one (20%) of whom had FAT breakthrough 1 month after discharge, and metoprolol was added. Neither FAT recurrence nor adverse effect (with or without beta-blocker) was observed during a median follow-up of 5 months.

CONCLUSION

Ivabradine is well-tolerated and may provide early heart rate control in pediatric FAT and can be considered early, especially in the presence of left ventricular dysfunction. Further investigations are deserved to confirm the optimal dose and long-term efficacy in this population.

WHAT IS KNOWN

• Focal atrial tachycardia (FAT) is the most common arrhythmia associated with tachycardia-induced cardiomyopathy (TIC) in children, and the efficacy of conventional antiarrhythmic medications in the treatment of FAT is poor. • Ivabradine is currently the only selective hyperpolarization-activated cyclic nucleotide-gated (HCN) inhibitor, which can effectively low HR without negative effect on blood pressure or inotropy.

WHAT IS NEW

• Ivabradine (0.1-0.2 mg/kg every 12 h) can effectively suppress focal atrial tachycardia in 50% of pediatric patients. • Ivabradine provides early control of heart rate and hemodynamic stabilization in children with severe left ventricular dysfunction due to atrial tachycardia within 48 h.

Treatment Strategy in Atrial Tachycardia Originating From the Atrial Appendage

Background: Atrial appendage tachycardia (AAT) originating from the atrial appendage (AA) is extremely difficult to eliminate using radiofrequency catheter ablation (RFCA). The optimal management strategy for AAT refractory to RFCA remains unclear.

Objective: This study aims to investigate the long-term result of ablative therapy and the optimal alternative management for AAT refractory to RFCA.

Methods: A total of 51 patients with AAT originating from the AA undergoing RFCA were recruited. Video-assisted atrial appendectomy and oral ivabradine were performed on those with AATs refractory to RFCA, and this study aimed to evaluate their safety and long-term efficacy.

Results: We included 51 patients (51/586, 8.7%) with AATs confirmed by activation mapping and contrast venography. Among them, there were 28 (54.9%) AATs originating from the distal AA. In total, 14 (27.4%) AATs were refractory to RFCA, including 13 originating from the distal AA and one arising from the proximal AA. Ten of 11 (90.9%) AATs originating from the distal AA were eliminated after an atrial appendectomy, and the other three AATs were suppressed using oral ivabradine. Origins from the distal AA refractory to RFCA and early age of AAT onset ≤26.5 years indicated the need for atrial appendectomy. No major complications occurred, and nine patients with tachycardia-induced cardiomyopathy fully recovered. Long-term success was achieved in 98.0% of patients with multiple treatment managements.

Conclusion: AATs originating from the distal AA were more refractory to RFCA. RFCA was the cornerstone of AAT catheter ablation. Video-assisted thoracoscopic atrial appendectomy was an effective strategy for those origins at the distal AA and the age of AAT onset ≤26.5 years. Ivabradine represents a promising treatment for AAT temporarily in pediatric and young adult patients.

Tachycardia-induced cardiomyopathy secondary to incessant ectopic atrial tachycardia in two infants: Potential new indication for early initiation of enteral ivabradine

This report describes two cases of tachycardia-induced cardiomyopathy secondary to incessant ectopic atrial tachycardia (EAT) in an infant presenting with severe left ventricular dysfunction and hemodynamic instability. The two cases were managed differently. The first required mechanical ventilation and was resistant to conventional antiarrhythmic drugs. After the initiation of enteral ivabradine (0.15mg/kg) the heart rate slowed with significant improvement in hemodynamics, peripheral perfusion and sinus rhythm was restored after 12 hours. Ivabradine was continued and the patient was discharged home after 10 days of hospitalization. The second case was managed by early initiation of ivabradine and resulted in restoration of sinus rhythm within 4 hours, thus avoiding trials of conventional anti-arrhythmic drugs with unstable hemodynamic profile. The infant was discharged after 5 days of hospitalization on ivabradine..

Ivabradine-sensitive incessant atrial tachycardia during pregnancy: a case report

Background 

Automaticity is the dominant mechanism in maternal focal atrial tachycardia (FAT) during pregnancy and if incessant, can cause tachycardia-induced cardiomyopathy. Medication failure for FATs is common, however, for the subgroup due to increased automaticity ivabradine sensitivity has been described and may represent a valuable treatment option. Little data are available regarding the safety profile of ivabradine during pregnancy.

Case Summary 

We report the case of a 38-year-old woman with background of peripartum cardiomyopathy and incessant atrial tachycardia with deteriorating ventricular function during her second pregnancy unresponsive to betablockade and demonstrating the immediate successful rate-controlling effect of ivabradine.

Discussion 

Early recognition of persistent maternal FAT is essential due to its frequent association with tachycardia-mediated cardiomyopathy. Our case report highlights the challenges of providing an equally safe and effective treatment of these notoriously difficult to treat arrhythmias during pregnancy. Ivabradine in combination with a betablocker can be effective for abnormal automaticity but its safety profile during pregnancy remains uncertain.

Ivabradine: A Potential Therapeutic for Children With Refractory SVT

Background: In April 2015, ivabradine was approved by the Food and Drug Administration for the treatment of patients with coronary artery disease and heart failure (HF). The use of this medication has been linked with improved clinical outcomes and reduced rates of hospitalization in patients with symptomatic HF and a baseline heart rate of 70 bpm and above. Nonetheless, little is known about the use of ivabradine in pediatric patients with supraventricular tachycardia (SVT). This use is not well-studied and is only endorsed by a few case reports and case series.

Aim: This study discusses the off-label utilization of ivabradine in pediatric patients with SVT, and highlights its efficacy in treating treatment-resistant (refractory) SVT.

Methods: We conducted a retrospective single-center observational study involving pediatric patients with SVT treated at our center between January 2016 and October 2020. We identified the total number of patients with SVT, and the number of patients with refractory SVT treated with Ivabradine. Similarly, we performed a thorough review of the databases of PubMed, Medline and Google Scholar to compare the clinical course of our patients to those described in the literature.

Results: Between January 2016 and October 2020, 79 pediatric patients with SVT were seen and treated at our center. A treatment-resistant SVT was noted only in three patients (4%). Ivabradine was used in these patients as a single or combined therapy. The rest (96%) were successfully treated with conventional anti-arrhythmics such as β-blockers, flecainide, and other approved medications. In the ivabradine group, successful reversal to sinus rhythm was achieved in two of the three patients (66%), one patient was treated with a combination therapy of amiodarone and ivabradine, and the other patient was treated only with ivabradine.

Conclusion: Overall, promissory results are associated with the use of ivabradine in pediatric patients with refractory SVT. Ivabradine appears to be a safe and well-tolerated medication that can induce adequate suppression of SVT, complete reversal to sinus rhythm, and effective enhancement of left ventricular function.

Use of ivabradine for treatment of junctional ectopic tachycardia in post congenital heart surgery

Cardiac surgeries especially involving crux of the heart as performed in tetralogy of Fallot (TOF) and pulmonary stenosis are mainly responsible for junctional ectopic tachycardia (JET). Diversified antiarrhythmic agents have been used in an impressive way to treat JET but showed suboptimal efficacy and varied associated adverse effects. But, ivabradine has proved as final crusader for its treatment. We report our initial experience of 4 cases in last 6 months with ivabradine in the management of postoperative JET. Encouraged by various reports and our increasing experience with ivabradine in heart failure population, we have moved to ivabradine as the first drug of choice for postoperative JET. Bradycardia was the only significant adverse effect in our series. The availability of atrial and ventricular pacing wires or at least transvenous temporary pacing should be ensured before starting ivabradine.