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.