Data collection
Baseline patient characteristics, ECG features and pacing indications were collected. Pacing thresholds, R-wave sensing amplitudes and lead impedances were measured both during uni- and bipolar pacing at implant and follow-up. Paced QRS morphology and duration were measured from stimulus to end-QRS. The stimulus to peak LVAT was measured from pacing stimulus to peak of the R wave in leads V5-V6 during LBBAP. Number of screw-in attempts, procedural and fluoroscopy times and acute procedure-related complications were recorded. All patients underwent post-procedural transthoracic echocardiographic evaluation to assess potential LBBAP implant-related complications.