Background: Little is known about the efficacy of permanent left bundle branch area pacing (LBBAP) in delivering cardiac resynchronization therapy (CRT). This study aimed to evaluate the effect of LBBAP on mechanical synchronization and myocardial work (MW) in heart failure (HF) patients and to compare LBBAP with biventricular pacing (BVP).Methods: This is a multicenter, prospective cohort study. From February 2018 to January 2021, 62 consecutive HF patients with reduced ejection fraction (LVEF ≤ 35%) and complete left bundle branch block (CLBBB) who underwent LBBAP or BVP were enrolled in this study. Echocardiograms and electrocardiograms and were conducted before and 3–6 months after implantation. Intra- and interventricular synchronization were assessed using two-dimensional speckle tracking imaging (2D-STI). The left ventricular pressure-strain loop was obtained by combining left ventricular strain with non-invasive blood pressure to evaluate mechanical efficiency.Results: The echocardiographic response rates were 68.6 and 88.9% in the BVP and LBBAP groups, respectively. Left bundle branch area pacing resulted in significant QRS narrowing (from 177.1 ± 16.7 to 113.0 ± 18.4 ms, P < 0.001) and improvement in LVEF (from 29.9 ± 4.8 to 47.1 ± 8.3%, P < 0.001). The global wasted work (GWW) (410.3 ± 166.6 vs. 283.0 ± 129.6 mmHg%, P = 0.001) and global work efficiency (GWE) (64.6 ± 7.8 vs. 80.5 ± 5.7%, P < 0.001) were significantly improved along with shorter peak strain dispersion (PSD) (143.4 ± 45.2 vs. 92.6 ± 35.1 ms, P < 0.001) and interventricular mechanical delay (IVMD) (56.4 ± 28.5 vs. 28.9 ± 19.0 ms, P < 0.001), indicating its efficiency in improving mechanical synchronization. In comparison with BVP, LBBAP delivered greater improvement of QRS narrowing (−64.1 ± 18.9 vs. −32.5 ± 22.3 ms, P < 0.001) and better mechanical synchronization and efficiency.Conclusions: Left bundle branch area pacing was effective in improving cardiac function, mechanical synchronization, and mechanical efficiency and may be a promising alternative cardiac resynchronization therapy.

Background Multiple studies illustrated that mitral valve (MV) leaflet presented variations, and there is little known about the posterior mitral leaflet (PML) anatomical variation affecting residual MR in interventional mitral valve edge-to-edge repair (TEER) with the ValveClamp system in patients with degenerative mitral regurgitation (DMR) using three-dimensional transesophageal echocardiography (3D TEE). Method Fifty-five DMR patients treated with TEER were included and performed 3D TEE pre- and post-procedure immediately. 3D TEE images were proceeded to characterize the posterior mitral leaflet anatomy and investigate the relationship between variations and residual mitral regurgitation (MR). Results Variations in PML were found in 16 patients (32%) of this series, including 3 cases (6%) of one scallop, 8 cases (16%) of two scallops, and 5 cases (10%) of four scallops. Residual MR ≥ 2+ were found in 3 patients with variant PML and 8 patients with classical PML post procedures, while other patients were all < 2+. The Chi-square test results showed no correlation between residual MR and PML variants (18.8% vs. 23.5, ᵪ = 0, p = 0.988). Of the 5 patients with 4 scallops, 3 had poor clinical outcomes. Two patients were converted to surgical mitral valve repair and one died 1 month after implantation. Conclusions 3D TEE provides a novel and non-invasive method to characterize and classify PML variations. Variations in PML are relatively common and not associated with residual MR 2+.

BackgroundThe purpose of the study was to determine the association between vena contracta area (VCA) and secondary leaflet tethering among mitral valve prolapse (MVP) patients, and thus to further identify and characterize an MVP with pathological leaflet tethering (MVPt+) phenotype.MethodsWe prospectively evaluated 94 consecutive MVP patients with significant mitral regurgitation (MR) and 21 healthy controls. MVPt+ group was defined as tenting volume index (TVi) > .7 mL/m2. The three‐dimensional (3D) geometry of mitral valve apparatus and VCA was measured with dedicated quantification software.ResultsOf the 94 patients with MVP and significant MR, 31 patients showed a TVi > .7 mL/m2 and entered the MVP with leaflet tethering (MVPt+) group. In stepwise multivariate analysis, only prolapse volume index and TVi were independently associated with 3D VCA. 3D VCA, annular area index, and plasma levels of NT‐proBNP were independently correlated with the severity of leaflet tethering. ROC curve revealed that a 3D VCA ≥ .55 cm2 is the optimal cutoff point to predict MVPt+ phenotype.ConclusionsSecondary leaflet tethering is a significant mechanism behind severe degenerative MR, resulting in an MVPt+ phenotype featuring more advanced morphological and hemodynamical characteristics.