# Study on the ultrasonic myocardial mechanics of left atrioventricular coupling in IBSH patients

## TL;DR

This study uses ultrasound to examine heart mechanics in patients with isolated basal septal hypertrophy, finding specific regions of strain and compensatory mechanisms.

## Contribution

The study identifies the basal septal segment as the most impaired region in IBSH and reveals compensatory redistribution in myocardial mechanics.

## Key findings

- IBSH patients showed increased global radial strain and reduced strain in the basal anterior and inferior septum.
- Left atrioventricular coupling index increased in IBSH and LVH groups, with marked changes in left atrial contraction strain in IBSH.
- LVMI negatively correlated with LVEF and strain parameters in IBSH patients.

## Abstract

This study aimed to evaluate the myocardial mechanical properties of the left atrium, left ventricle, and left atrioventricular coupling using ultrasound in patients with isolated basal septal hypertrophy (IBSH) caused by primary hypertension.

This retrospective study enrolled 210 participants [140 hypertensive patients subdivided into IBSH and left ventricular hypertrophy (LVH) groups (n = 70 each) and 70 controls]. Speckle-tracking echocardiography was used to analyze left atrium (LA)/left ventricle (LV) strain parameters and atrioventricular coupling.

(1) The IBSH group demonstrated higher adherence to antihypertensive medication than the LVH group (P < 0.05). (2) Both the IBSH and LVH groups showed reduced global longitudinal strain (GLS) and global circumferential strain (GCS) (more severe in LVH) but increased global radial strain (GRS) (more prominent in IBSH) (P < 0.05). The 18-segment LV strain analysis revealed significantly reduced strain in the basal anterior and inferior septum (P < 0.05), while compensatory increased strain in all apical segments (P < 0.05) in the IBSH group. (3) Left atrioventricular coupling index (LACI) increased in both groups (P < 0.01), while left atrial reservoir strain (LASR) and left atrial conduit strain (LASCD) decreased (more in LVH), yet left atrial contraction strain (LASCT) markedly rose in IBSH (P < 0.01). (4) Correlation analysis in the IBSH group showed the following results: Left ventricular mass index (LVMI) negatively correlated with left ventricular ejection fraction (LVEF), GRS, and GCS (P < 0.05); LACI positively correlated with left atrial volume index(LAVI) (r = 0.73); LASR positively correlated with GLS and E/A but negatively with E/e′ (all P < 0.05).

This study elucidates the potential association between regular antihypertensive medication use and cardiac remodeling in patients with IBSH. Through a comprehensive analysis of global and regional left atrioventricular myocardial function, we identified the basal septal segment as the most significantly impaired myocardial region. Furthermore, the study demonstrated the existence of a compensatory redistribution mechanism in myocardial mechanics.