RESUMO
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..