AV reentrant and idiopathic ventricular double tachycardias: complicated interactions between two tachycardias

An electrophysiological study was performed in a 61 year old man with Wolff -Parkinson-White (WPW) syndrome. At baseline, neither ventricular nor supra ventricular tachycardias could be induced. During isoprenaline infusion, ve ntricular tachycardia originating from the right ventricular outflow tract (RVOT) with a cycle length of 280 ms was induced and subsequently atriovent ricular reentrant tachycardia (AVRT) with a cycle length of 300 ms using an accessory pathway in the left free wall appeared, During these tachycardia s, AVRT was entrained by ventricular tachycardia. The earliest ventricular activation site during the ventricular tachycardia was determined to be the RVOT site and a radiofrequency current at 30 W successfully ablated the ve ntricular tachycardia at this site. The left free wall accessory pathway wa s also successfully ablated during right ventricular pacing. The coexistenc e of WPW syndrome and cathecolamine sensitive ventricular tachycardia origi nating from the RVOT has rarely been reported. Furthermore, the tachycardia s were triggered by previous tachycardias.