Role of contact force in ischemic scar-related ventricular tachycardia ablation; optimal force required and impact of left ventricular access route

Background Contact force-sensing technology has become a widely used addition to catheter ablation procedures. Neither the optimal contact force required to achieve adequate lesion formation in the ventricle, nor the impact of left ventricular access route on contact force has been fully clarified. Patients and methods Consecutive patients ( n = 24) with ischemic cardiomyopathy who underwent ablation for scar-related ventricular tachycardia were included in the study. All ablations ( n = 25) were performed using irrigated contact force-sensing catheters (Smart Touch, Biosense Webster). Effective lesion formation was defined as electrical unexcitability post ablation at sites which were electrically excitable prior to ablation (unipolar pacing at 10 mA, 2 ms pulse width). We explored the contact force which achieved effective lesion formation and the impact of left ventricular access route (retrograde aortic or transseptal) on the contact force achieved in various segments of the left ventricle. Scar zone was defined as bipolar signal amplitude