Feasibility of the epicardial approach to the Bachman’s bundle
In each patient, we evaluated the technical feasibility of different approaches to the roof of the LA, where the fibers of BB connecting right and left atria in the epicardium can be found and ablated. The roof of the LA represents the floor of the transverse sinus, a tubular structure enveloped by pericardium which forms during organogenesis.15
In all but two cases (n=23, 92%), the transverse sinus could be reached from the left, advancing the catheter anteriorly to the lateral ridge (Figure 5). A rightward approach to the transverse sinus was feasible in 12 patients (48%) by passing close to the septal portion of right atrial appendage (Supplemental Figure 1a), and in seven patients passing laterally to the right atrial appendage (28%, Supplemental Figure 1b). The leftward approach proved to be significantly more feasible than other rightward approaches (Fisher’s test p = 0.019).