Análisis de los factores anatómicos que pueden determinar que se afecte el sistema de conducción av durante el reemplazo transcatéter de la válvula aórtica

Abstract

Transcatheter aortic valve implantation is the chosen treatment in inoperable patients with aortic stenosis. Due to the close anatomical relation between the atrioventricular conduction system and the aortic valve, the expansion of a valvular prosthesis against the aortic valve may lead to conduction abnormalities, resulting in partial or complete heart block and the need to implant a permanent pacemaker. There are some variants in which the conduction system is exposed, being susceptible to injuries, such as: the variable position of the atrioventricular node and the His bundle, the membranous septum length, the presence of calcifications in the aortic leaflets, the interventricular septum thickness and the prosthesis depth. In our research, we studied 57 hearts with macroscopic and optical microscopy techniques, observing these variations and finding possible risk of injury during percutaneous valve implantation due to: a shorter membranous septum in length in 17.5% of the cases; a deviation toward the left side of the division of the His bundle in 22 hearts; 10 hearts have a membranous septum with a thickness ≥11 mm, 6 mm from the crest of the muscular interventricular septum; the presence of calcifications in the central fibrous body, membranous septum and non-coronary sinus of the aortic valve in 47% of the cases; and a fragmentation of the atrioventricular node in islands of conduction tissue in 9% of the cases.