Layer-specific quantification of myocardial deformation may disclose the subclinical systolic dysfunction and the mechanism of preserved ejection fraction in patients with hypertension

Background Systemic hypertension (HTN) leads to left ventricular (LV) remodeling, which results in diastolic dysfunction in the presence of preserved ejection fraction (EF). The goal of this study was to explore subclinical LV systolic dysfunction and the mechanism of preserved EF using layer-specific quantification of myocardial deformation in HTN patients. Methods One hundred and twenty HTN patients (mean blood pressure (BP) 165 ± 20/ 96 ± 16 mmHg) and 120 age and gender matched volunteers (mean BP 120 ± 10/76 ± 8 mmHg) were studied. Left ventricular echocardiographic parameters including LV ejection fraction (LVEF), global and regional peak longitudinal, circumferential 2D systolic layer strain and LV twist were measured. The associations between these parameters were studied against LV relative wall thickness (RWT) and LV mass index. Results LVEF was normal in all HTN patients. The RWT and LV mass index were higher in HTN group (0.40 ± 0.06 vs 0.35 ± 0.03, p < 0.0001; 84 ± 24 vs 63 ± 11 g/m2, p < 0.0001). The absolute value of layer and global longitudinal strain was significantly lower in HTN group (−24 ± 3 vs −26 ± 3%, p < 0.0001;. 21 ± 3 vs −23 ± 3%, p < 0.0001, respectively). Global circumferential strain (−40 ± 6 vs −35 ± 5%, −31 ± 7 vs −27 ± 4% respectively, p < 0.0001), and the LV twist (23 ± 5 vs 18 ± 6 degree, p < 0.0001) were higher in HTN group. Conclusions This study revealed that hypertension resulted in increased RWT and LV mass. Impairment in layer and global longitudinal strain found in HTN patients may indicate early systolic dysfunction due to impaired endomyocardial function. Enhancement of circumferential strain and LV twist may be a compensatory mechanism to maintain LVEF in these patients.