Using preoperative cardiac computed tomographic conduction axis prediction to avoid damage in congenital left ventricular outflow tract and aortic valve surgery.

OBJECTIVE: Postoperative high-grade atrioventricular block is prevalent following congenital aortic valve, root and left ventricular outflow tract (LVOT) surgery. We aimed to evaluate the application of presurgical cardiac computed tomography (CT) estimation of the conduction axis in mitigating this issue.

METHODS: Patients with congenital aortic valve, root and LVOT disease evaluated and operated in our center from February 2022 to August 2025 who underwent presurgical CT with intact central fibrous body were included. Anatomical landmarks were used to estimate the atrioventricular node (point A), His bundle course (point B), and left bundle branch origin (point C) relative to the aortic virtual basal ring plane, and guide avoidance during cardiac surgery.

RESULTS: Fifty-three patients were included (mean age, 32 years [range, 2-68 years]; 72% male). The most common diagnoses were bileaflet (70%) and unileaflet (10%) aortic valves, and LVOT obstruction (7%). Points A, B, and C were located at a mean depth of +11.8 ± 4.8 mm, +3.3 ± 3.2 mm, and +1.5 ± 2.7 mm inferior to the aortic virtual basal ring plane, respectively. Some form of aortic valve repair was performed in 38 patients (72%). The remaining 15 patients (28%) underwent some form of aortic valve replacement. One patient (1.9%) developed high-grade atrioventricular block with permanent pacemaker insertion, with subsequent spontaneous resolution. This incidence compared favorably to our prior report of 10% in a similar cohort without pre-surgical CT conduction system estimation.

CONCLUSIONS: This CT-based conduction axis estimation may mitigate conduction damage risk during congenital LVOT, aortic valve, and root surgery. Further prospective multisurgeon, multicenter studies are necessary to validate this approach.