[Cardiac permanent pacemaker after transcatheter aortic valve implantation: A predictive and scientific review]

Evaluation of Conduction Disorders after Aortic Valve Replacement with Rapid Deployment Bioprostheses

Objective

The aim of this retrospective, single-center study was to evaluate the occurrence of conduction disorders after rapid deployment aortic bioprosthesis implantation.

Methods

Electrocardiograms of patients undergoing INTUITY (Edwards Lifesciences, Irvine, CA USA) bioprosthesis implantation were collected at admission, during postoperative course, and at discharge. Primary end point was the occurrence of new-onset conduction disorders, defined as complete left bundle branch block, complete right bundle branch block, permanent pacemaker implantation, and worsening of pre-existing rhythm abnormalities. Secondary end points were the assessment of preoperative and postoperative QRS duration and the identification of transitory conduction disorders.

Results

Forty-four patients (July 2015–December 2016) were included in the analysis. Preoperatively, patients with normal conduction and with already existing disorders were 25 (56.8%) and 19 (43.2%), respectively. Primary end point occurred in 14 patients (31.8%). Two patients (4.5%) received pacemaker implantation. In patients with normal preoperative conduction, new abnormalities were found in eight cases (32%): all left bundle branch blocks with one pacemaker implantation. Worsening of pre-existing conduction disorders was found in six patients (31.6%) with one pacemaker implantation. QRS duration increased in 20 patients (45.4%), and average increase was 37 milliseconds. Overall, we observed a significant increase of QRS (96 ± 21 milliseconds vs. 111 ± 28 milliseconds, P < 0.001). Three patients experienced a new-onset temporary left bundle branch block.

Conclusions

New-onset conduction disorders or worsening of pre-existing rhythm abnormalities occur in one third of patients after rapid deployment aortic bioprosthesis implantation. Although the incidence of postoperative pacemaker implantation before discharge is low, strict follow-up is mandatory to identify a potential need for pacemaker implantation in a timely manner.

Transient left anterior and septal fascicular blocks after self-expandable percutaneous transcatheter aortic valve implantation

Transcatheter aortic valve implantation (TAVI) is indicated in severe symptomatic aortic stenosis, when there is intermediate-high surgical risk, or a condition considered inoperable, as in the case of "porcelain aorta" that could turn clamping or cannulation of the ascending aorta hazardous in open-heart surgery. Among the complications of this less invasive procedure, intraventricular conduction disorders subsequent to the procedure stand out. TAVI causes worsening of intraventricular dromotropic disorders in more than 75% of the cases, with the presence of preexisting right bundle branch block and first-degree atrioventricular block, deep prosthesis implant, male gender, size of the aortic annulus smaller than the prosthesis, and porcelain aorta being predictive of requirement for permanent pacemaker implant.