Transcatheter aortic valve implantation-induced left bundle branch block: causes and consequences

Transcatheter aortic valve implantation (TAVI) is an alternative treatment option for patients with severe aortic valve stenosis who do not qualify for surgical aortic valve replacement (AVR). Besides its proven clinical benefits, one of the complications of TAVI is the creation of conduction abnormalities, like left bundle branch block (LBBB). New LBBB occurs between 7 and 65% of cases, numbers that differ considerably between devices. In this review, we discuss the possible causes and the clinical significance of TAVI-induced LBBB. Several device- and procedural-related factors seem responsible for the development of LBBB, of which depth of implantation and balloon-annulus diameter ratio are the most important ones. TAVI-induced LBBB negatively affects cardiac function and hospitalization, but its impact on mortality is subject of debate. Future research and registries should implement strict diagnostic criteria for LBBB together with recording of its timing and persistence.