January 31, 2015
View Full PaperPercutaneous Epicardial Ablation of Ventricular Arrhythmias Arising From the Left Ventricular Summit
Key Result
Percutaneous epicardial ablation of left ventricular summit arrhythmias was successful in 22% of patients, with specific ECG criteria predicting success with 100% sensitivity and 72% specificity.
Study Design
Type
Observational (n=23)
Structured PICO
Does percutaneous epicardial ablation successfully treat ventricular arrhythmias arising from the left ventricular summit in patients with prior unsuccessful endocardial ablation?
P
Population
23 consecutive patients (mean age 49 ± 14 years; 39% men) with ventricular arrhythmias arising from the left ventricular summit who underwent percutaneous epicardial instrumentation for mapping and ablation because of unsuccessful ablation from the coronary venous system and multiple endocardial LV/right ventricular sites.
I
Intervention
Percutaneous epicardial mapping and ablation
O
Outcome
Successful epicardial ablation and ECG features associated with successful ablation
Epicardial ablation for LV summit ventricular arrhythmias has a low success rate due to anatomical constraints, but specific surface ECG criteria can accurately identify the subset of patients likely to have a successful procedure.
Abstract
BACKGROUND: Percutaneous epicardial ablation of ventricular arrhythmias arising from the left ventricular summit is limited by the presence of major coronary vessels and epicardial fat. We report the outcomes of percutaneous epicardial mapping and ablation of ventricular arrhythmias arising from the left ventricular summit and the ECG features associated with successful ablation. METHODS AND RESULTS: Between January 2003 and December 2012, a total of 23 consecutive patients (49 ± 14 years; 39% men) with ventricular arrhythmias arising from the left ventricular summit underwent percutaneous epicardial instrumentation for mapping and ablation because of unsuccessful ablation from the coronary venous system and multiple endocardial LV/right ventricular sites. Successful epicardial ablation was achieved in 5 (22%) patients. In the remaining 18 (78%) cases, ablation was aborted for either close proximity to major coronary arteries or poor energy delivery over epicardial fat. The Q-wave amplitude ratio in aVL/aVR was higher in the successful group, with a ratio of > 1.85 present in 4 (80%) patients in the successful group versus 2 (11%) in the unsuccessful group (P = 0.008). The ratio of R/S wave in V1 was greater in the successful group, with 4 (80%) patients in the successful group having a R/S ratio of > 2 in V1 versus 5 (28%) in the unsuccessful group (P = 0.056). None of the patients in the successful group had an initial q wave in lead V1, as opposed to 6 (33%) in the unsuccessful group. The presence of at least 2 of the 3 ECG criteria above predicted successful ablation with 100% sensitivity and 72% specificity. CONCLUSIONS: Epicardial instrumentation for mapping and ablation of ventricular arrhythmias arising from the left ventricular summit is successful only in a minority of patients because of close proximity to major coronary arteries and epicardial fat. A Q-wave ratio of > 1.85 in aVL/aVR, a R/S ratio of > 2 in V1, and absence of q waves in lead V1 help identify appropriate candidates for epicardial ablation.