Electroanatomical Mapping‐Guided Endocardial and Epicardial Ablation of Sustained Ventricular Tachycardia Originating From Alcohol Septal Ablation‐Induced Scar in a Patient With Hypertrophic Obstructive Cardiomyopathy

Ventricular Tachycardia After Alcohol Septal Ablation. A 76-year-old female developed 2 different ventricular tachycardias (VTs) 5 years after alcohol septal ablation (ASA) for symptomatic hypertrophic obstructive cardiomyopathy. VT#1 was a small macroreentry at the anterior border of the low-voltage zone, suggesting the ASA-scar and eliminated by endocardial ablation at a site recording fractionated potentials covering the mid-diastolic and presystolic periods. VT#2 was a focal VT and eliminated by epicardial cryoablation at the basal posterior left ventricle, suggesting the posterior border of the ASA-scar. Using the electroanatomical mapping, we demonstrated that the mechanism of the VTs was reentry at the edge of the ASA-scar.