INTRODUCTION
Among several risk factors, hypertension remains the leading cause of cardiovascular mortality among several risk factors (1). Myocardial structural and geometrical changes (i.e., left ventricular concentric remodeling and eccentric and concentric left ventricular hypertrophy) are accompanied by altered systolic and diastolic function (2). Thus, current guidelines have primarily implemented geometrical measurements of the left ventricle (LV) for cardiovascular risk management in the hypertensive population. However, previous studies on systolic and diastolic functional markers of the LV have indicated an even higher potential for risk stratification (Kuznetsova 2016).
Speckle-tracking echocardiography provides a comprehensive assessment of the global and segmental myocardial mechanics. Global longitudinal strain (GLS) is more sensitive than LV ejection fraction in detecting subtle systolic dysfunction even in the absence of overt heart failure (3). In addition, GLS is a more sensitive marker and robust predictor of cardiovascular events (4, 5). Segmental strain and strain rate (S/SR) reflect altered global and regional functions owing to geometrical changes in hypertensive hearts (6). However, only a limited number of studies have focused on segmental strain in hypertensive populations, and only a few studies have compared global longitudinal or regional myocardial function between patients with hypertension and those with normal cardiac function (7-10). The strain values of different myocardial layers have been reported to be of potential clinical interest (4, 5, 11) but have not been specifically described in subjects with hypertension. Segmental diastolic strain rates in early diastole and atrial contraction (SR E and SR A) have not been previously described in hypertensive populations.
The aim of this study was to investigate the S/SR-based characteristics of the LV in hypertensive subjects and to compare segmental layer S/SR with normal subjects. Patients with hypertension vary from those with accidentally measured high blood pressure to those with well or insufficiently regulated blood pressure under medication. To gain more knowledge about the effect of high blood pressure or well-regulated hypertension on cardiac global and segmental function, this study also aimed to investigate functional differences between groups graded by antihypertensive treatment and the degree of BP elevation. Higher basal-apical gradients due to high afterload in the healthy hypertensive population may be confused with pathological changes. Therefore, this study further aimed to determine the expected segmental S/SR values in an otherwise healthy hypertensive population.