Left ventricular systolic motion pattern differs among patients with left bundle branch block patterns.

Yan Chen,Chun Chen,Huan Tang,Beibei Ge,Jing Yao,Yan Shen,Changqing Miao,Di Xu,Yanjuan Zhang

doi:10.1007/s10554-022-02528-9

Abstract

The study aimed to investigate left ventricular (LV) motion pattern in patients with LBBB patterns including patients with pacemaker rhythm (PM), type B Wolff-Parkinson-White syndrome (B-WPW), premature ventricular complexes originating from the right ventricular outflow tract (RVOT-PVC), and complete left bundle branch block (CLBBB). 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, and CLBBB with normal LV ejection fraction, and in age-matched control subjects. 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, PM, and RVOT-PVC. 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.

Highlights

Left bundle branch block (LBBB) is a common cardiac arrhythmia
It has been reported that approximately 90% of LBBB cases are associated with cardiovascular disease[1], and about 25% of heart failure patients have a history of LBBB[2]
There are three other types of conduction disorders with a similar electricity conduction pattern —pacemaker rhythm (PM), type B Wolff-Parkinson-White syndrome (B-WPW), and premature ventricular complexes originating from the right ventricle (RVOT-PVC)

Summary

Introduction

Left bundle branch block (LBBB) is a common cardiac arrhythmia. Wide QRS complex duration and deterioration of left ventricular (LV) systolic and diastolic functions occurring due to LBBB are risk factors for the development and progression of heart failure. The alterations in LV mechanical activation sequences in LBBB patients are attributed to abnormal electrical activation. Due to the blockage of the left bundle branch, electricity is conducted through normal cardiac myocytes in the LV free wall instead of Purkinje fibers. There are three other types of conduction disorders with a similar electricity conduction pattern —pacemaker rhythm (PM), type B Wolff-Parkinson-White syndrome (B-WPW), and premature ventricular complexes originating from the right ventricle (RVOT-PVC). All four abnormal conditions were defined as LBBB pattern conduction disorders in the present study

Methods

Results

Discussion

Conclusion