Effect of Epicardial Fat on Electroanatomical Mapping and Epicardial Catheter Ablation

Self Cite

147

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.

Section: Ecg Features Associated With Successful Epicardial Ablationmentioning

confidence: 99%

Percutaneous Epicardial Ablation of Ventricular Arrhythmias Arising From the Left Ventricular Summit

Santangeli

Marchlinski

Zado

et al. 2015

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147

“…To minimize the effect of epicardial fat on low-voltage area measurements, the anterior interventricular sulcus and the AV grove (defined as the first centimeter from mitral and tricuspid annuli) were not considered for segmentation when contouring epicardial low-voltage areas. 23 The distribution of LAVA sites with respect to this substrate was analyzed, and the density of LAVA sites per centimeter square of substrate was assessed and compared between the RV and the LV. To avoid a double counting of LAVAs, 2 sites were considered different if the distance between both sites was >3 mm.…”

Section: Post Hoc Analysismentioning

confidence: 99%

Characterization of the Left-Sided Substrate in Arrhythmogenic Right Ventricular Cardiomyopathy

Berte

Denis

Amraoui

et al. 2015

Background-The correlates of left ventricular (LV) substrate in arrhythmogenic right ventricular (RV) cardiomyopathy are largely unknown. Methods and Results-Thirty-two patients with arrhythmogenic RV cardiomyopathy (47±14 years; 6 women) were included. RV and LV dysplasia were defined from multidetector computed tomography and cardiac magnetic resonance imaging. Arrhythmias were characterized as right-sided or left-sided on 12-lead ECG recordings at baseline and during isoproterenol testing. In 14 patients, the imaging substrate was compared with voltage mapping and local abnormal ventricular activity. Imaging abnormalities were found in 32 (100%) and 21 (66%) patients on the RV and LV, respectively, intramyocardial fat on multidetector computed tomography being the most sensitive feature. LV involvement related to none of the Task Force criteria. Right-sided arrhythmias were more frequent than left-sided arrhythmias (P=0.003) although the latter were more frequent in case of LV involvement (P=0.02). The agreement between low voltage and fat on multidetector computed tomography was high on the RV when using either endocardial unipolar or epicardial bipolar data (κ=0.82 and κ=0.78, respectively) but lower on the LV (κ=0.54 for epicardial bipolar). LV local abnormal ventricular activity was found in all patients with LV involvement, and none of the others. The density of local abnormal ventricular activity within fat areas was similar between the RV and LV (P=0.57). Conclusions-LV substrate is frequent in arrhythmogenic RV cardiomyopathy, but poorly identified by current diagnostic strategies. Left-sided arrhythmias are more frequent in case of LV involvement. LV fat hosts the same density of local abnormal ventricular activity as RV fat, but is less efficiently detected by voltage mapping. These results support the need for alternative diagnostic strategies to identify LV dysplasia. (Circ Arrhythm Electrophysiol.

“…This underscores the importance of identifying both structures and understanding their anatomic relationship with coronary arteries before and during epicardial mapping and ablation. 13 Currently there is no accepted strategy for this purpose. Additionally, it has been suggested that ablation from epicardial veins would be feasible, 12,14 but our results indicate that ablating in close proximity to the epicardial coronary arteries without venous structure interposed could potentially lead to more severe vessel injuries.…”

Section: Present Findingsmentioning

confidence: 99%

Acute and Chronic Effects of Epicardial Radiofrequency Applications Delivered on Epicardial Coronary Arteries

Viles-González

Miranda

Scanavacca

et al. 2011

Background-Epicardial coronary injury is by far the most feared complication of epicardial ablation. Little information is available regarding the chronic effects of delivering radiofrequency in the vicinity of large coronary vessels, and the long-term impact of this approach for mapping and ablation on epicardial vessel integrity is poorly understood. Therefore, the aim of this study was to characterize the acute and chronic histopathologic changes produced by in vivo epicardial pulses of radiofrequency ablation on coronary artery of porcine hearts. Methods and Results-Seven pigs underwent a left thoracotomy. The catheter was sutured adjacent to the left anterior descending artery and left circumflex artery, and 20 pulses of radiofrequency energy were applied. Radiofrequency lesions located no more than 1 mm of the vessel were used for this analysis. Three animals were euthanized 20 days (acute phase) after the procedure and 4 animals after 70 days (chronic phase). The following parameters were obtained in each vessel analyzed: (1) internal and external perimeter; (2) vessel wall thickness; (3) tunica media thickness, and (4) tunica intima thickness. The presence of adipose tissue around the coronary arteries, the distance between the artery and the epicardium, and the anatomic relationship of the artery with the coronary vein was also documented for each section. Sixteen of 20 (80%) sections analyzed, showed intimal thickening with a mean of 0.18Ϯ0.14 mm compared with 0.13Ϯ0.16 mm in the acute phase (Pϭ0.331). The mean tunica media thickness was 0.25Ϯ0.10 mm in the chronic phase animals compared with 0.18Ϯ0.03 mm in the acute phase animals (Pϭ0.021). A clear protective effect of pericardial fat and coronary veins was also present. A positive correlation between depth of radiofrequency lesion and the degree of vessel injury expressed as intimal and media thickening (Pϭ0.001) was present. A negative correlation was identified (rϭϪ0.83; Pϭ0.002) between intimal thickening and distance between epicardium and coronary artery. Conclusions-In this porcine model of in vivo epicardial radiofrequency ablation in proximity to coronary arteries leads to acute and chronic histopathologic changes characterized by tunica intima and media thickening, with replacement of smooth muscle cells with extracellular matrix, but no significant stenosis was observed up to 70 days after the ablation. The absence of acute coronary occlusion or injury does not preclude subsequent significant arterial damage, which frequently occurs when epicardial radiofrequency applications are delivered in close vicinity to the vessels. (Circ Arrhythm Electrophysiol. 2011;4:526-531.)