Apical ventricular tachycardia morphology in left ventricular nonischemic cardiomyopathy predicts poor transplant-free survival

BACKGROUND The scar of patients with left ventricular (LV) nonischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) typically originates at or near the mitral annulus and extends a variable distance toward the apex. OBJECTIVE To determine whether electrocardiograms of VT with LV apical exit sites would identify patients with larger scars extending a greater distance from the base toward the apex and decreased heart transplant/left ventricular assist device (LVAD)-free survival. METHODS Consecutive patients with LV NICM undergoing VT ablation between May 2008 and April 2011 were studied. All electrocardiograms of spontaneous and induced VT were analyzed. Apical VT was defined as left bundle branch morphology with precordial transition >= V-5 or right bundle branch morphology with precordial transition <= V-3. Scar percentage was defined as the area of low voltage divided by the total surface area. RESULTS Thirty-two of 76 patients had 1 or more apical VTs. Those with apical VTs had larger percentage of endocardial and epicardial bipolar scars (14.9% vs 8.1%, P = .01, and 15.5% vs 5.5%, P = .03, respectively), scar that, although originating from the periannular region (94.7% of the patients), was more likely to extend apically beyond the basal half (48.3% vs 24.4%, P = .05 endocardial, and 85.7% vs 25.9%, P = .07 epicardial), and worse transplant/LVAD-free survival during a mean follow-up of 332 days (P = .006). CONCLUSIONS Patients with NICM and apical VTs have larger voltage abnormality extending as contiguous or patchy scar from the base further toward the apex and worse transplant/LVAD-free survival. Particular attention should be paid to optimal heart failure management in these patients, with more guarded prognosis