Loss of Septal Q Waves Is Associated With QRS Widening After Transcatheter Aortic Valve Implantation

ABSTRACT Background Conduction disturbances remain a common complication following transcatheter aortic valve implantation (TAVI). While baseline conduction abnormalities are well‐established predictors of post‐procedural conduction disease or permanent pacemaker implantation, risk stratification in patients without baseline PR or QRS prolongation remains limited. Loss of septal Q waves (LSQ) may reflect underlying conduction system vulnerability but has not been systematically evaluated in this setting. Methods We conducted a retrospective observational study of consecutive patients undergoing TAVI at a single tertiary center between 2018 and 2024. Patients without baseline PR or QRS prolongation were included. LSQ was defined as the absence of Q waves in leads I, V5, and V6. The primary outcome was an increase in QRS duration ≥ 20 ms. Results Among 87 patients without baseline PR or QRS prolongation, 86 were evaluable for the primary outcome and QRS widening ≥20 ms occurred in 31 patients (36.0%). LSQ was present in 40.2% of patients. LSQ was associated with increased odds of QRS widening in unadjusted analysis (OR 2.71, 95% CI 1.09‐6.74; p = 0.031). The association remained significant after adjustment for AF (adjusted OR 2.76, 95% CI 1.07‐7.11; p = 0.035) (Table 2). AF was also independently associated with QRS widening (adjusted OR 3.79, 95% CI 1.10‐13.08; p = 0.035). Conclusion LSQ on pre‐procedural ECG was independently associated with post‐procedural QRS widening in patients undergoing TAVI without baseline PR or QRS prolongation. LSQ may serve as a simple, non‐invasive marker of conduction system vulnerability with potential utility in risk stratification and post‐procedural monitoring. These findings are hypothesis generating and warrant validation in larger prospective cohorts.