Analysis of global and regional right ventricular strain in patients with left bundle branch block using cardiac MRI

Abstract

Left bundle branch block (LBBB) is a common conduction disorder leading to typical morphological phenomena. The aim of the following study is to measure right ventricular (RV) functional and strain parameters in patients with LBBB using cardiac magnetic resonance imaging (cMRI) and compare them with those of a healthy control group. 41 patients (median age 57 years) and 41 healthy controls (median age 38 years, 18 female each), who underwent comprehensive cMRI, were retrospectively included. Right ventricle CINE-sequences were analysed by semi-automated segmentation using CVI42 (Circle Cardiovascular Imaging, Calgary, Canada) for functional, and Segment (Medviso, Lund, Sweden) for strain analysis. All parameters were tested for statistically significant differences using Wilcoxon test followed by Bonferoni-Holm correction. Patients had statistically significant impaired RV global longitudinal strain (LS) (median, − 15.40%[IQR, − 18.40 to − 10.97%] vs. − 18.40% [IQR, − 20.85 to − 16.50%]; p < 0.001), RV global circumferential strain (CS) (median, − 9.40% [IQR, − 12.90 to − 5.00%] vs. − 13.60% [IQR, − 15.35 to − 12.03%]; p < 0.001) and RV mid-ventricular CS (median, − 8.42% [IQR, − 10.83 to − 4.95%] vs. − 11.34% [IQR, − 14.58 to − 8.72%]; p < 0.001) compared to controls. Subdividing the RV into lateral and septal segments showed significant differences in septal LS, septal CS and septal mid-ventricular CS in patients with LBBB compared to controls. All RV strain parameters were impaired in patients with LBBB compared to healthy controls with the septum being the driving differentiator.