not-yet-known not-yet-known not-yet-known unknown Introduction: Transcatheter aortic valve implantation (TAVI) is a treatment for severe aortic stenosis in high-risk and intermediate-risk patients unsuitable for surgery. Despite its minimally invasive nature, TAVI often leads to complications, including de novo left bundle branch block (LBBB), which increases the risk of complete atrioventricular (AV) block, heart failure, and sudden cardiac death. Current guidelines provide ambiguous recommendations for permanent pacemaker (PPM) implantation for patients with LBBB post-TAVI. This report aims to reevaluate the HV interval cutoff and explore alternative predictors for PPM decisions in patients with LBBB after TAVI. Case Description: A 79-year-old female with non-obstructive coronary artery disease and severe symptomatic aortic stenosis underwent TAVI with a 26 mm Edwards Resilia balloon-expandable valve. Pre-TAVI electrocardiography (ECG) showed sinus rhythm with a QRS duration of 98 ms. Post-TAVI, the patient developed a first-degree AV delay and new-onset LBBB. An electrophysiological study (EPS) performed 48 hours post-TAVI showed an HV interval of 61 ms. Despite this, the patient developed symptomatic complete heart block hours later, necessitating urgent PPM implantation. Discussion: This case questions the reliability of the HV interval as a standalone marker for pacemaker decisions in LBBB post-TAVI patients. The occurrence of complete heart block despite an HV interval below predictive values raises concerns about this parameter’s accuracy. Alternative predictors such as the delta HV interval and AH interval may provide better insights. Delayed EPS assessment might be more appropriate. Conclusion: Managing LBBB after TAVI is complex. Reevaluation of HV interval reliability and larger trials to establish accurate predictors and refine PPM implantation criteria post-TAVI are needed to improve patient outcomes.

The HD-grid multipolar mapping catheter has emerged as an invaluable tool for greater effectiveness of pulmonary vein isolation (PVI). In the cases described below, fractionated signals seen with the HD-grid catheter at the LAA and LSPV junction were ablated. These signals likely would not be visualized with conventional catheters and may cause recurrences due to incomplete PVI. The directional sensitivity limitations of bipolar electrogram recordings and the unique anatomy of the LAA-LSPV ridge further contribute to the challenge of evaluating pulmonary vein isolation. The HD-grid catheter’s ability to record bipoles parallel and perpendicular to the catheter splines and its high-density mapping capabilities provide a superior means of identifying gaps in ablation and detecting the low-voltage isthmus. Furthermore, factors such as ablation quality, catheter stability, and the thickness of the LAA-LSPV ridge influence the presence of fractionated signals and the success of PVI. Incorporating pre-procedure imaging modalities such as CT or MRI and real-time intracardiac echocardiography could enhance the tailored approach to address these challenges. Future developments in HD-grid technology, including contact force measurement during mapping, may offer additional insights into the nature of these signals. This case series highlights the significance of utilizing the HD-grid catheter for detailed interrogation of the LAA-LSPV ridge, ultimately leading to more effective PVI and improved outcomes in patients with afib

The Left bundle branch area pacing (LBBAP) is a novel pacing strategy that utilizes the conduction system distal to the left bundle branch block level for direct activation of the left bundle and the right ventricular myocardium. Our meta-analysis compared the structural, electrophysiological, clinical, and procedural outcomes of LBBAP and Bi-ventricular pacing (BVP). The meta-analysis included two randomized control trials and showed significant reductions in left ventricular systolic and diastolic volumes with LBBAP compared to BVP, along with a statistically significant decrease in QRS duration, NYHA class, and heart failure hospitalizations. Fluoroscopic time was also significantly shorter in the LBBAP group. However, no significant change in LV ejection fraction was noted. Although not statistically significant, procedural complications were slightly higher in the LBBAP group. Our findings suggest that LBBAP may be a superior alternative to standard BVP in improving structural and electrophysiological components and clinical components of cardiomyopathy, including NYHA class and heart failure hospitalizations. LBBAP is a more physiological pacing strategy that results in normal ventricular activation and may be a viable alternative to BVP for cardiac synchronization therapy.