Successful catheter ablation of two types of ventricular tachycardias triggered by cardiac resynchronization therapy: a case report.

We report a case of a patient with nonischemic dilated cardiomyopathy and implantable cardioverter-defibrillator, in whom an upgrade to biventricular pacing triggered multiple episodes of ventricular tachycardias (VTs) of two morphologies. First VT presented as repetitive nonsustained arrhythmia of the same morphology as isolated ectopic beats, suggesting its focal origin. Second VT was reentrant and was triggered by the former ectopy, leading to a therapy from the device. Electroanatomical mapping of the left ventricle revealed relatively small low voltage area in the left ventricular outflow tract and identified both an arrhythmogenic focus as well as critical isthmus for reentrant VT. Radiofrequency catheter ablation successfully abolished both VTs. After the procedure, biventricular pacing was continued without any recurrences during a period of 24 months. The report emphasizes the role of catheter ablation in management of VTs triggered by cardiac resynchronization therapy.