Cardioverter-defibrillator oversensing due to double counting of ventricular tachycardia electrograms

We report a case of a patient with idiopathic dilated cardiomyopathy and recurrent ventricular tachycardias refractory to antiarrhythmic treatment with amiodarone. A cardioverter defibrillator implantation was performed by the transvenous technique, but ventricular tachycardia detection resulted to be inappropriate because of constant double sensing of ventricular tachycardia electrograms (QRS width=250 ms). Device programmability didnʹt allow a satisfactory solution to this problem, therefore a more appropriate sensing system was considered. Through an anterior thoracotomy two epicardial wires were positioned and sensing by these wires, placed closer to ventricular tachycardia origin, resulted appropriate. An electrophysiologic study and subsequent follow up confirmed appropriate ICD detection of ventricular tachycardias. This case emphasizes how in some cases sensing by epicardial wires may be a solution for QRS double counting occurring with endocardial leads during ventricular tachycardia.