Amiodarone and Catheter Ablation as Cardiac Resynchronization Therapy for Children with Dilated Cardiomyopathy and Wolff-Parkinson-White Syndrome
A previously healthy 3-month-old boy was presented with an abnormal electrocardiography (ECG) at a routine check-up for a hydrocele operation. His body weight was 5.5 kg, and his cardiac examination was notable for a normal S1 and a grade II/VI regurgitant systolic murmur heard at the apex. At admission, overt ventricular preexcitation was noted on 12-lead ECG. The vector of the AP suggested a right-sided pathway. A chest X-ray showed severe cardiomegaly with increased pulmonary vascular markings. Echocardiography revealed paradoxical septal motion, severe mitral regurgitation and global hypokinesia with a 22.9% of left ventricle ejection fraction (LVEF, normal range: 55-65% at his age) and dilated left ventricle, with an end-diastolic dimension (LVEDD) of 54.6 mm (normal range: 22-28 mm at his age). Digoxin, captopril, diuretics, and carvedilol were given, but cardiac function remained poor.\nAt five of his age, supraventricular tachycardia developed. Based on poor LVEF and tachycardia, a trial of amiodarone was administered. After amiodarone treatment, a shortening of the QRS duration (130 ms vs. 117 ms) and delta wave disappearance were noted on ECG, with improved general condition.\nThere was significant improvement of LVEF (27% vs. 39%, normal range: 55-65% at his age) and reduction of LVEDD (58 mm vs. 52 mm, normal range 30-38 mm). However, reduction of amiodarone dosage brought the increase of the QRS duration (117 ms vs. 126 ms), with deterioration of the LVEF ( and ). After confirming the effect of preexcitation on left ventricular function, RFCA of the right anterior AP was successfully performed, resulting in LVEF improvement (19% vs. 38%), reduction of LVEDD (58.3 mm vs. 54.6 mm), shortening of QRS duration (126 ms vs. 80 ms) and disappearance of preexcitation (). Echocardiography also showed disappearance of left ventricle dyssynchrony (). The patient is doing well with gradual improvement of left ventricular function.