Ablation of postinfarction ventricular tachycardia guided by isolated diastolic potentials.

Frequent recurrences of ventricular tachycardia (VT) despite implantable cardioverter-defibrillator (ICD) and antiarrhythmic drug therapy are a typical indication for catheter ablation. We performed endocardial mapping of an haemodynamically tolerated VT in a 67-year-old male patient. Isolated diastolic potentials (IDPs) of similar morphology were recorded during atrial paced rhythm at baseline and during monomorphic VT. The isolated potentials were required for initiation and maintenance of ventricular arrhythmia. These diastolic electrograms were considered to be part of the reentry circuit, as they remained constantly associated with VT during oscillations of cycle length and resetting. Validation of the ablation target was not performed by exact entrainment pacing in order to test the predictive value of the observed diagnostic phenomena. Radiofrequency (RF) energy applications were successful at the site where IDPs were recorded during atrial paced rhythm and VT. Ablation decreased the need for ICD therapies effectively in a patient with scar-related, slow VT.