A total of 181 patients with severe aortic stenosis treated with this prosthesis and studied by electrocardiography between April 2008 and December 2013 were selected. A subgroup of 137 (75.7%) consecutive patients was studied by intracardiac electrocardiogram before and after prosthesis implantation. The primary endpoint of the study was the need for a permanent pacemaker within 72 hours after prosthesis implantation. Numerous variables to predict this possibility were analyzed.
Following implantation, PR and QRS intervals were increased from 173 ± 47 ms to 190 ± 52 ms (P < .01) and from 98 ± 22 ms to 129 ± 24 ms (P < .01), whereas the A-H and H-V intervals were prolonged from 95 ± 39 ms to 108 ± 41 ms (P < .01) and from 54 ± 10 ms to 66 ± 23 ms (P < .01). A total of 89 (49%) patients had new-onset left bundle-branch block, and 33 (25%) required a pacemaker within the first 72 hours. The independent predictors for a pacemaker were baseline right bundle-branch block and prosthetic depth. Intracardiac intervals had no predictive value. In addition, 13 patients required a pacemaker after 72 hours.
CoreValve prosthesis implantation has a high incidence of conduction disturbance, with left bundle-branch block being the most common. A total of 25% of patients required a permanent pacemaker. The need for a pacemaker was related to baseline right bundle-branch block and prosthetic depth.