Single Versus Dual Lead Atrioventricular Sequential Pacing for Acquired Atrioventricular Block During Transcatheter Aortic Valve Implantation Procedures

Cellular regeneration as a potential strategy to treat cardiac conduction disorders

Loss of atrioventricular conduction system (AVCS) cells due to either inherited or acquired deficits leads to conduction diseases, which can deteriorate into fatal cardiac arrhythmias and sudden death. In this issue of the JCI, Wang et al. constructed a mouse model of atrioventricular block (AVB) by inducing AVCS cell-specific injury using the Cx30.2 enhancer to drive expression of diphtheria toxin fragment A. AVCS cell ablation in adult mice led to irreversible AVB. jkjkIn contrast, AVCS cell injury in neonatal mice was followed by spontaneous recovery in a subset of mice, revealing a limited postnatal time window during which the regeneration of AVCS cells can occur as a result of cellular plasticity. This exciting study paves the way for future research into biological or cellular treatment approaches for cardiac conduction diseases by exploiting the regenerative potential of AVCS cells.

One-year pacing dependency after pacemaker implantation in patients undergoing transcatheter aortic valve implantation: Systematic review and meta-analysis

Objectives

Atrioventricular conductions disturbances, requiring permanent pacemaker implantation (PPI), represent a potential complication after transcatheter aortic valve implantation (TAVI), However, little is known about the pacemaker dependency after PPI in this patient setting. This systematic review analyses the incidence of PPI, the short-term (1-year) pacing dependency, and predictors for such a state after TAVI.

Methods

We performed a systematic search in PUBMED, EMBASE, and MEDLINE to identify potentially relevant literature investigating PPI requirement and dependency after TAVI. Study data, patients, and procedural characteristics were extracted. Odds ratio (OR) with 95% confidence intervals were extracted.

Results

Data from 23 studies were obtained that included 18,610 patients. The crude incidence of PPI after TAVI was 17% (range, 8.8%-32%). PPI occurred at a median time of 3.2 days (range, 0-30 days). Pacing dependency at 1-year was 47.5% (range, 7%-89%). Self-expandable prosthesis (pooled OR was 2.14 [1.15-3.96]) and baseline right bundle branch block (pooled OR was 2.01 [1.06-3.83]) showed 2-fold greater risk to maintain PPI dependency at 1 year after TAVI.

Conclusions

Although PPI represents a rather frequent event after TAVI, conduction disorders have a temporary nature in almost 50% of the cases with recovery and stabilization after discharge. Preoperative conduction abnormality and type of TAVI are associated with higher PPI dependency at short term.