Vol.:(0123456789) 1 3
The International Journal of Cardiovascular Imaging
https://doi.org/10.1007/s10554-020-01947-w
ORIGINAL PAPER
Myocardial strain indices and coronary fow reserve are only mildly
afected in healthy hypertensive patients
Dimitrios Evangelou
1
· Aris Bechlioulis
1
· Georgios Tzeltzes
1
· Lampros Lakkas
1
· Ioanna Theodorou
2
·
Rigas Kalaitzidis
2
· Evangelia Dounousi
2
· Lampros K. Michalis
1
· Katerina K. Naka
1
Received: 29 March 2020 / Accepted: 20 July 2020
© Springer Nature B.V. 2020
Abstract
To investigate changes in two-dimensional myocardial strain echocardiography (2DSTE) indices following a dipyridamole
stress test (DIPSE) in relatively healthy hypertensive patients and healthy controls. Forty-seven male hypertensive patients
(aged 57±9 years) with normal ejection fraction and without left ventricular (LV) hypertrophy and 20 healthy male subjects
were studied with conventional and 2DSTE echocardiography at rest and post DIPSE. Coronary fow reserve (CFR) in the left
anterior descending artery following DIPSE was also evaluated. Global longitudinal strain (GLS) and TWIST were higher
while UNTWIST rate was lower in hypertensives versus controls (p < 0.05 for all); TWIST remained higher in hypertensives
(p = 0.021) after adjustment for diferences in age and body mass index (BMI) between the groups. CFR was higher in con-
trols compared to hypertensives even after adjustment for confounders (4.14 vs. 2.53, p = 0.001). DIPSE-induced changes
did not difer between the groups after adjustment for age and BMI (p > 0.05 for all). DIPSE–induced improvement in GLS
was associated with higher CFR only in hypertensive patients (r − 0.372, p = 0.010). The current study showed that well
controlled hypertensive patients have only mild echocardiographic diferences compared to controls; some of these difer-
ences appear to depend on age and BMI. A ‘hyper-rotation’ phenomenon (i.e. higher TWIST) early in hypertension may be
a compensatory mechanism to preserve global systolic LV function. Coronary microcirculatory function was impaired in
hypertensive patients, albeit within normal range, and was associated with DIPSE-induced changes in myocardial long-axis
systolic function.
Keywords Arterial hypertension · Myocardial strain · Speckle tracking · Dipyridamole stress test · Coronary fow reserve
Introduction
Arterial hypertension (AH) is a major risk factor for cardio-
vascular disease and is associated with functional and struc-
tural changes in the heart and the vasculature. AH promotes
myocardial hypertrophy, cardiomyocyte apoptosis and myo-
cardial fbrosis through various mechanical (wall tension,
volume load, blood viscosity) and neurohormonal patho-
physiological pathways (activation of sympathetic and renin
angiotensin aldosterone system, activation or inhibition of
several humoral and genetic factors and other intracellular
signals) [1]. These alterations may lead to impaired dias-
tolic flling and systolic contraction of the left ventricle (LV)
associated with clinical or subclinical cardiac dysfunction.
AH also afects the peripheral vasculature causing arte-
rial endothelial dysfunction, accelerated vascular stifening,
increased progression of interstitial and perivascular fbro-
sis [2], vascular remodeling and reduction in the number of
small arterioles (i.e. microangiopathy) [3]. Coronary micro-
circulation may be damaged either directly from vascular
changes [2] or through the elevation of the LV diastolic pres-
sure causing increased extravascular compression leading
to impaired coronary fow reserve (CFR). Previous clinical
studies have shown that impaired CFR may lead to exercise-
induced myocardial ischaemia and to exercise-induced LV
Dimitrios Evangelou and Aris Bechlioulis have contributed
equally to this work.
* Katerina K. Naka
anaka@uoi.gr; drkknaka@gmail.com
1
2nd Department of Cardiology, University of Ioannina
Medical School, University Campus, 45110 Ioannina,
Greece
2
Department of Nephrology, University Hospital of Ioannina,
Ioannina, Greece