Sinus tachycardia due to hyperthyroidism is generally treated with beta-blockers. But some patients do not respond to beta-blockers or may have non-tolerable side effects or have contraindications. We presented a case with persistent sinus tachycardia secondary to hyperthyroidism refractory to maximal doses of propranolol. After ivabradine treatment, her heart rate was < 100 bpm within 24 hours. There were no electrocardiogram changes or side effects. The use of ivabradine is promising and can be considered in cases where tachycardia cannot be controlled in children with hyperthyroidism.

We encountered a paediatric case of graft failure due to antibody-mediated rejection after heart transplantation in which ivabradine was effective. Inappropriate sinus tachycardia in denervated transplanted hearts is a good indication for ivabradine administration as beta-blockers have a limited efficacy. To our knowledge, this is the first report on the effectiveness of ivabradine in a paediatric heart transplant rejection case.

Congenital junctional ectopic tachycardia is a rare but serious cardiac arrhythmia seen in neonates and young infants. It is frequently resistant and refractory to first-line treatment options such as cardioversion with adenosine and direct current shock, and it carries a high morbidity and mortality rate. The aim of this article is to present the case of congenital junctional ectopic tachycardia observed in a 14-day-old neonate, highlighting the role of ivabradine in the management, followed by a discussion about current approaches to treatment.

Multifocal atrial tachycardia has certain electrocardiographic similarities to atrial fibrillation. The mechanism of atrial fibrillation is heterogenous but in some cases may arise from a single ectopic driver with fibrillatory conduction to the rest of the atria. This has led to the speculation that multifocal atrial tachycardia may have a similar mechanistic unifocal site that disperses through the atrium in a fibrillatory pattern. Ivabradine has been reported to be efficacious in an adult with paroxysmal atrial fibrillation as well as in children with junctional or ectopic atrial tachycardias. This is the first report of successfully using ivabradine, a novel anti-arrhythmic If blocking agent, to convert multifocal atrial tachycardia in a 5-month-old critically ill infant to a pattern indicating a single ectopic atrial focus. This allowed the patient’s single atrial focus to be ablated with return to sinus rhythm and decannulation from ventriculoarterial extracorporeal membrane oxygenation. This case suggests that multifocal atrial tachycardia may arise from a single automatic focus with downstream fibrillatory conduction to the atria.