Background Functional tricuspid regurgitation (FTR) is correlated with more symptoms and higher mortality. The purpose of this study was to analyze the effect of left bundle branch area pacing (LBBAP) on FTR in patients with persistent atrial fibrillation (AF) and bradycardia. Methods Consecutive patients with a pacemaker indication who underwent successful LBBAP were identified between July 2018 and March 2023. Patients who met the following criteria were included: 1) persistent AF; 2) mean heart rate (HR) < 60 bpm; 3) moderate or severe FTR. The severity of FTR was graded qualitatively with a multi-integrative approach, classified into three grades: mild = 1, moderate = 2, and severe = 3. FTR improvement was defined as adding at least one grade of FTR level. Echocardiographic parameters were followed up for one week and 6 months. Results There were 29 patients enrolled. 17 (59%) patients were moderate FTR and 12 (41%) patients were severe FTR at baseline. The paced QRS duration showed no difference compared to baseline (112.9 ± 13.9 vs 113.8 ± 29.1 ms, P=0.856). The paced HR was 65.4 ± 6.9 bpm, was significantly higher than that of baseline (46.7 ± 8.0 bpm) (P <0.001). The VP percentage at one week was 85.9 ± 20.6%, and remained stable during 6 months follow-up (81.0 ± 19.2%) (P=0.159). One week after LBBAP, 15 (52%) patients had FTR improvement. The mean FTR degree was decreased from 2.4 ± 0.5 to 1.9 ± 0.7, P<0.001. Six months after LBBAP, 13 (45%) patients remained with FTR improvement. The mean FTR degree was decreased from 2.4 ± 0.5 to 2.0 ± 0.8, P<0.001. Conclusion LBBAP was able to improve FTR in persistent AF patients with bradycardia.

Background: The electrical activation patterns in pacemaker rhythm, type B Wolff-Parkinson-White syndrome, and premature ventricular complexes originating from the right ventricular outflow tract are similar to those of the complete left bundle branch block and can be considered as LBBB patterns. Methods: Two-dimensional speckle tracking was used to evaluate peak value and time to peak value of the LV twist, LV apex rotation, and LV base rotation in patients with PM, B-WPW, RVOT-PVC, CLBBB, and in age-matched control subjects. The apical-basal rotation delay was calculated as the index of LV dyssynchrony. Results: The LV motion patterns were altered in all patients compared to the control groups. Patients with PM and CLBBB had a similar LV motion pattern with a reduced peak value of LV apex rotation and LV twist. Patients with B-WPW demonstrated the opposite trend in the reduction of LV rotation peak value, which was more dominant in the basal layer. The most impairment in the LV twist/rotation peak value was identified in patients with RVOT-PVC. Compared to the control group, the apical-basal rotation delay was prolonged in patients with CLBBB, followed by those with B-WPW, RVAP, and RVOT-PVC. Conclusions: The LV motion patterns were different among patients with different patterns of LBBB. CLBBB and PM demonstrated a reduction in LV twist/rotation that was pronounced in the apical layer, B-WPW showed a reduction in the basal layer, and RVOT-PVC in both layers. CLBBB had the most pronounced LV apical-basal rotation dyssynchrony.

Background: We aimed to evaluate the effect of Bachmann bundle (BB) impairment on electrical and mechanical function of the left atrium (LA), as well as the long-term clinical impact of such impairment. Design: We measured activation time in the five LA walls in 56 patients with atrial fibrillation. LA reservoir, conduit, and contractile function were also evaluated. Patients were divided into two groups based on ablation strategy: the circumferential pulmonary vein isolation (CPVI) group and CPVI with anterior wall linear ablation (LAWA) group. Patients in the CPVI+LAWA group were divided into two sub-groups based on ECG differences following ablation: the BB impairment group and intact BB group. LA activation time and function were then compared between the ablation strategy groups and the CPVI+LAWA subgroups. Results: Patients in the CPVI+LAWA group exhibited longer activation times in the anterior and lateral walls of the LA, poorer LA synchrony, and reduced LA contractile and reservoir function when compared with those in the CPVI group. In the BB impairment subgroup, we observed a discrepancy between electrical/mechanical remodeling. Among five walls, activation time was longest in this region. BB impairment was also associated with reduced LA function. Conclusion: Significant changes in LA function and conductibility were observed in patients with anterior wall ablation, especially those with iatrogenic BB impairment.