Right-sided accessary pathways in patients with Wolff-Parkinson-White (WPW) syndrome may cause cardiac dyssynchrony and dilated cardiomyopathy, with a characteristic septal shape, irrespective of any supraventricular tachycardia episodes. We report on two infants (13 and 5 months), whose right-sided accessary pathway-induced dilated cardiomyopathy was successfully treated by flecainide for the first time. After the flecainide administration, an abnormal aneurysmal dilation of the basal interventricular septum was almost restored to normal, and the decreased ejection fraction recovered. Flecainide use may be an important therapeutic option for this entity to avoid catheter ablation during infancy.(Int Heart J 2019; 60: 1201-1205)

A 3-year-old boy was referred to our hospital for management of Kawasaki disease at 5 days of illness. Echocardiographic examination on admission suggested aneurysmal dilation of the right coronary artery and a possible aorta-left main trunk connection. However, detailed echocardiography at 12 days of illness revealed an abnormal bifurcation of the proximal right coronary artery and no real connection of the aorta-left main trunk, all of which indicated the presence of a single right coronary artery. These diagnoses were confirmed by selective coronary angiography, which was performed later. Considering the difficulties in diagnosing congenital coronary anomalies, which may increase the risk of future fatal events, knowing the disease entity of the congenital coronary arterial anomaly is important for the accurate evaluation of coronary arteries in patients with Kawasaki disease. To the best of our knowledge, this is the first case report of a patient with Kawasaki disease complicated by a single right coronary artery; however, following a search of the literature, we found a brief conference abstract written in Japanese relating to the same clinical condition.