Title : Hemodynamic force analysis as a novel marker for evaluating left bundle branch area pacing: A case report
Abstract:
Background: Conventional Right Ventricular Pacing (RVP) induces electrical and mechanical dyssynchrony, potentially leading to pacing-induced cardiomyopathy, reduced Left Ventricular Ejection Fraction (LVEF), and progression of heart failure. Left Bundle Branch Area Pacing (LBBAP) offers a more physiological activation of the ventricles by engaging the intrinsic conduction system, preserving synchrony, and maintaining ventricular function. However, traditional parameters such as QRS duration and LVEF may not fully reflect mechanical efficiency or predict response. Hemodynamic Force (HDF) analysis, a novel echocardiographic tool, quantifies intraventricular flow dynamics and may serve as a sensitive marker for assessing resynchronization.
Objective: To evaluate the changes in intraventricular hemodynamic forces following LBBAP implantation and explore their potential value in assessing pacing efficacy.
Methods: This case report presents a patient with atrioventricular conduction disturbance and moderately reduced LVEF who underwent LBBAP implantation. The evaluation included pre- and post-implant 12-lead ECG, conventional 2D echocardiography, and HDF analysis using QStrain Echo v4.2 (Medis). Assessed HDF parameters included longitudinal Apex–Base and transverse Latero–Septal forces, the net force directional angle, and the Apex–Base/Lateral force ratio.
Results: A 66-year-old female presented with exertional dyspnea and fatigue. Her history included coronary artery disease and NYHA class II heart failure. ECG revealed second-degree AV block (Mobitz II) and right bundle branch block. Baseline echocardiography showed a moderately reduced LVEF of 48.1%. Following LBBAP implantation, LVEF increased to 53.2%. Apex–Base hemodynamic force rose from 10.21% to 16.97%, and Latero–Septal force slightly increased from 1.69% to 2.20%. The directional angle shifted from 74° to 77°, reflecting improved alignment of intraventricular forces along the physiological axis. The force ratio decreased from 16.60 to 13.00, indicating a more balanced force distribution and enhanced mechanical coordination.
Conclusion: LBBAP successfully improved electromechanical synchrony and intraventricular flow dynamics in this patient. HDF analysis emerged as a sensitive and non-invasive tool for evaluating pacing effectiveness. This case supports further investigation of HDF parameters in larger cohorts to refine patient selection and optimize pacing strategies.
