Combined epicardial and transapical endocardial radiofrequency ablation for ventricular tachycardia with ventricular aneurysm in a porcine model

Objective To evaluate the feasibility and validity of combined directly epicardial and transapical endocardial substrate ablation guided by Carto mapping for ventricular tachycardia(VT) with left ventricular aneurysm(LVA) intra-operation in a swine model. Methods Twenty-four swine models with sustained VT and LVA were randomly divided into study group(radiofrequency ablation, RFCA, from epicardium via direct-view and endocardium via transapical access, 12 cases) and control group(endocardial RFCA via retrograde transaortic access, 12 cases). Substrate mapping for captured abnormal potentials via endocardium and epicardium was used to precisely locate the low-voltage areas. After ablation in two groups, VT was induced again to compare the effectiveness of different RFCA strategies. Results Three dimensional electro-anatomic mapping was implemented successfully in two groups under open chest. And VT substrates were largely located in the border zone of LVA. All objects in the study group underwent endocardial ablation via transapical access smoothly without operative failure. When VT inducing again, 2 cases of study group was with inducible VT, however, VT recurrence in control group was 5 cases, P=0.04. Conclusion Combined direct epicardial and transapical endocardial substrate mapping and ablation appeared to be feasible and effective for treating VT with LVA under thoracotomy. Key words: Tachycardia, ventricular; Ventricular aneurysm; Radiofrequency ablation; Animal model