The impact of aortic root rotation on the position of the fibrous trigones on the mitral annulus.

Abstract

Objectives: Aortic root (AoR) rotation is a significant factor influencing the structures around the aortic valve and the atrioventricular conduction system. However, its relationship with the mitral valve remains unexplored. The goal of this study was to investigate the impact of AoR rotation on the mitral annulus, particularly the fibrous trigones, and on the atrioventricular conduction system following mitral valve surgery.

Methods: We retrospectively reviewed 100 patients who underwent mitral valve surgery in which electrocardiography-gated computed tomography angiography scans were used to identify rotational variants of the AoR. AoR rotation was classified as clockwise, central or counterclockwise relative to the atrial septum. The positions of the fibrous trigones and postoperative atrioventricular conduction disturbances were analysed.

Results: The distance from the right fibrous trigone to the right edge of the mitral annulus was shortest in the clockwise group and longest in the counterclockwise group (clockwise vs central vs counterclockwise: 6.1 ± 2.0 mm vs 7.4 ± 1.9 mm vs 8.7 ± 1.5 mm, P < 0.001). The incidence of new-onset atrioventricular and bundle branch blocks was significantly higher in patients with AoR rotation (clockwise vs central vs counterclockwise: 63.2% vs 4.1% vs 21.9%, P < 0.001).

Conclusions: AoR rotation influences the position of the fibrous trigone and is a risk factor for postoperative atrioventricular conduction disturbances. Computed tomography is a valuable tool for assessing AoR rotation and mitral annulus morphology.