Conduction Abnormalities after Transcatheter Aortic Valve Replacement: Pretty Common, Fairly Predictable, Barely Avoidable

The cardiac conduction system is commonly diseased in patients with aortic valve disease, and the site of conduction defect in those with severe calcific aortic valve stenosis is most commonly the His bundle or infra-Hisian.^, The bundle of His traverses the membranous septum towards the left ventricular outflow tract (LVOT) running superficially over the crest of the ventricular septum, originating the left bundle branch. This anatomical course makes the His bundle and its left branch susceptible to mechanical injury during transcatheter aortic valve replacement (TAVR), which involves multiple mechanical manipulations with wires, catheters, balloons, and the transcatheter heart valve (THV) inflow within that vicinity. Atrioventricular and intra-ventricular conduction abnormalities are indeed a common finding in patients with severe aortic valve stenosis referred to TAVR and new onset persistent conduction abnormalities (NOPCAs) are a common complication arising during/after TAVR.

Unlike other periprocedural complications of TAVR, whose incidence has decreased over time, a regression in the incidence of NOPCAs after TAVR was neither seen with the introduction of new TAVR technologies/techniques nor it is foreseeable in the near future.

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