CORRELATES OF LEFT ATRIAL RESERVOIR STRAIN IN A NIGERIAN HYPERTENSIVE COHORT

Background Left atrial (LA) reservoir strain (LARS), measured by four-dimensional automated LA quantification (4D Auto LAQ), reflects dynamic LA deformation during ventricular systole. Its physiological correlates in African hypertensives, a population with a high burden of hypertensive heart disease, have not been characterised.

Methods 101 consecutive hypertensives (57 male; mean age 52±12 years; BMI 30±7 kg/m²; SBP 130±13 mmHg) underwent comprehensive 3D echocardiography with 4D Auto LAQ software. LARS (longitudinal component) was correlated with age, BMI, SBP, DBP, LVMI, LAEF, E/e', GLS, biplane LAVI, and 3D LAVI using Pearson and Spearman analyses. Independent predictors were identified by multivariable linear regression.

Results Mean LARS was 22.9±7.7% (range 10.0–56.0%). On univariable analysis, LARS correlated significantly with age (r=−0.398; p<0.001), LAEF (r=+0.379; p<0.001), LVMI (r=−0.221; p=0.026), biplane LAVI (r=−0.196; p=0.049), and LV GLS (ρ=−0.211; p=0.034). Left atrial reservoir strain did not correlate with SBP, DBP, E/e', or 3D LAVI. On multivariable regression (R²=0.282; adjusted R²=0.220), only age (β=−0.190; 95% CI −0.305 to −0.076; p=0.001) and LAEF (β=+0.299; 95% CI +0.130 to +0.468; p=0.001) were independent predictors of LARS. Sex did not significantly influence LARS (p=0.165).

Conclusions In Nigerian hypertensives, 4D LARS is principally determined by age-related LA mechanical decline and LA ejection function, independent of loading conditions or LV geometry.