PE3-034 A Case of Left Ventricular Noncompaction Accompanying Fasciculo-Ventricular Accessory Pathway and Atrial Flutter

Left ventricular hypertrabeculation/noncompaction(LVHT) is an uncommon type of genetic cardiomyopathy characterized by trabeculations and recesses within the ventricular myocardium. Frequently associated arrhythmias included atrial fibrillation, ventricular arrhythmias, atrioventricular block, and Wolff-Parkinson-White syndrome. A 29-year-old male presented with palpitations and shortness of breath. The ECG showed pre-excitation and anteroseptal accessory pathway was suspected. The echocardiogram revealed prominent trabeculations and deep recesses in the left ventricles. The recesses were perfused by intraventricular flow. During the echocardiographic examination, tachycardia developed spontaneously. The ECG showed wide complex tachycardia and the QRS morphology was similar to that of sinus rhythm. An electrophysiologic study was performed. Decremental atrial pacing caused prolongation of both AH and AV intervals in parallel. The HV interval and the degree of preexcitation remained unchanged from both right atrial and coronary sinus pacing with atrial extrastimuli. The His bundle pacing failed to normalize the QRS width. A diagnosis of fasciculo-ventricular accessory pathway was made. Decremental pacing on the proximal coronary sinus area induced typical atrial flutter, which was identical to the clinical tachycardia. A line of block was made across the cavo-tricuspid isthmus(CTI). A rare presentation of LVHT with fasciculo-ventricular accessory pathway and atrial flutter was successfully treated with conventional CTI block.