Prospective and Randomized Study to Evaluate Efficacy and Safety of Epicardial Ventricular Tachycardia Ablation Using Contact Force Sensor Irrigated Tip Catheter - Pilot Study

Pilot Study Design The investigators will select 20 ischemic or non-ischemic cardiomyopathy patients with scar related Ventricular tachycardia with indication of VT ablation. After informed consent, these patients will be randomized to endocardial only (Control Group) or combined endocardial and epicardial ablation (Treatment Group).

Inclusion Criteria Patients with ischemic and non-ischemic cardiomyopathy and recurrent sustained monomorphic VT requiring cardioversion or antiarrhythmic drug administration with ≥4 episodes in the previous 6 months despite an ICD or antiarrhythmic drug therapy. Patients without ICD were eligible after 2 episodes of sustained VT.

Exclusion Criteria Creatinine level >2.5mg/dL; LV ejection fraction <10%; NYHA Class IV; mobile thrombus on LV; absence of vascular access to the LV; life-expectancy of less than 12 months; previous open-chest cardiac surgical procedure; unstable angina; myocardial infarction in the last 2 months; severe aortic stenosis; severe mitral regurgitation secondary to leaflet or chordae rupture; pregnancy and age of less than 18 years old.

Ablation Technique In the patients randomized for combined epicardial and endocardial ablation, subxyphoid puncture will be performed according to previously described technique. Following successful epicardial access on the combined epi and endocardial ablation and following the venous puncture on the endocardial only group, a puncture of femoral artery will be performed. If the patient has peripheral artery disease, the catheter will be positioned on the left ventricle through transeptal puncture.

Electroanatomic voltage map will be constructed of the endocardial and epicardial surface. After map construction, programmed ventricular stimulation of the apex of the RV with S4 extrastimuli will be performed aiming for VT inducibility. If the induced VT is well tolerated, activation mapping of the VT will be constructed in addition to entrainment mapping. If the VT is not hemodynamically tolerated, it will be reverted either by Burst or electrical cardioversion, than substrate modification in the scar combined with pace-mapping and local abnormal electrograms (late potentials) ablation will be performed. In the patients in the endocardial only group, only the endocardial surface of the right or left ventricle will be ablated.