Left atrial mechanics evaluated by two-dimensional strain analysis: alterations in essential hypertension

Abstract

BACKGROUND: Hypertension is a cardiovascular risk factor that predisposes to cardiac structural alterations namely increased left ventricular (LV) wall thickness, reduced LV compliance and diastolic dysfunction, with consequent left atrial (LA) dilation and functional impairment. In this article, we evaluated differences in left atrial structure and function using two-dimensional speckle tracking echocardiography in patients with hypertension compared with controls. METHODS: This was a retrospective cross-sectional study of 208 hypertensive patients and 157 controls who underwent a comprehensive transthoracic echocardiogram. Patients with hypertension were stratified by the presence of left ventricular hypertrophy (LVH). RESULTS: Non-LVH hypertension patients had lower left atrial reservoir strain (LAS RES ) (34.78 +/- 29.78 vs. 29.78 +/- 6.08; P = 0.022) and conduit strain (LAS CD ) (19.66 +/- 7.29 vs. 14.23 +/- 4.59; P = 0.014) vs. controls despite similar left atrial volumes (LAV) . Left atrial contractile strain (LAS CT ) was not significantly different between non-LVH hypertension patients and controls (15.12 +/- 3.77 vs. 15.56 +/- 3.79; P = 0.601). Left atrial mechanical dispersion was significantly higher in the LVH group compared with the non-LVH hypertension group (42.26 +/- 13.01 vs. 50.06 +/- 14.95; P = 0.009). In multivariate regression analysis, LVH correlated with left atrial mechanical dispersion ( P = 0.016). An age-hypertension interaction independently correlated with LAS CT ( P < 0.001). CONCLUSION: Hypertension results in functional left atrial changes even before development of LV hypertrophy and structural left atrial changes with increased left atrial volume. We demonstrate both a likely hypertension-associated left atrial myopathy that prevents age-related compensatory increase in left atrial contractile function, and impact of LVH in hypertension on left atrial dyssynchrony.