Abstract 15010: Prevalence Distribution and Response to Endocardial Ablation of Abnormal Epicardial Recordings in Patients with Ischemic Cardiomyopathy
Introduction: Endocardial catheter ablation for ventricular arrhythmias (VA) and electrical storm (ES) in patients with ischemic cardiomyopathy has shown moderate long term results. The reported need for epicardial ablation in these patients is around 12%. We investigated the impact of epicardial elimination of all abnormal potentials (AP) within the scar to increase the long-term ablation success rate.
Methods: Fifty-three consecutive patients with ischemic cardiomyopathy and VAs and or ES undergoing VAs ablation at our Institution were enrolled in this study. Epicardial access was obtained in all patients before ablation. All patients underwent endocardial and epicardial mapping and ablation of all AP within the scar in sinus rhythm.
Results: Before ablation, the clinical VT was inducible endocardially in 81% of the cases (43pts). Interestingly in 9% of the cases (5 patients), the clinical VT could be induced only from the epicardial scar containing APs and was not inducible in the remaining 5 cases. APs were present endocardially in all patients and epicardially in 45% of the cases (24 patients). The presence of epicardial APs reduced from 45% (24pts) to 32 % (17 pts) because in 9 cases endocardial ablation of APs was able to eliminate or modify epicardial APs within the scar. Interestingly, post ablation VT inducibility of all type was present almost in all cases when all APs were not completely eliminated endocardially and or epicardially. The overall agreement between VT inducibility and AP elimination was 58% ( 95% CI 0.38 - 0.96, p < 0.01 %), with a positive percent agreement of 64% (95% CI 0.51-0.82) and negative percent agreement of 28% (95% CI 0.18-0.47). During a mean follow-up of 29±18 months, the VAs recurrence rate of any ventricular tachycardia (VTs) was 19% (10/53) pts. One patient died at follow up for non cardiac reasons.
Conclusions: Endo-epicardial ablation of all abnormal potentials in patients with VAs increases the freedom from VAs at follow up. To render patients non-inducible, epicardial ablation was required in nearly 30% of cases. The elimination of epicardial potentials with endocardial ablation highlights the presence of mid-miocardial channels or connectiosn between the endocardial and the epicardial recordings.
- © 2012 by American Heart Association, Inc.