C. Palombo et al., Early impairment of coronary flow reserve and increase in minimum coronaryresistance in borderline hypertensive patients, J HYPERTENS, 18(4), 2000, pp. 453-459
Citations number
27
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
Objective To evaluate relations between coronary flow velocity and myocardi
al oxygen demand at rest, as well as coronary vasodilator capacity and flow
reserve, in asymptomatic subjects with borderline hypertension as compared
to normotensive controls and patients with sustained high blood pressure (
HBP) and without left ventricular hypertrophy (LVH).
Subjects and methods Forty-two asymptomatic males were studied: 13 healthy
normotensive volunteers; 12 subjects with borderline HBP and 17 asymptomati
c subjects with sustained systemic hypertension. Coronary flow velocity in
left anterior descending artery and coronary flow reserve were assessed by
transesophageal echo-doppler at baseline and during intravenous adenosine i
nfusion. Left ventricular mass, peak systolic wall stress (PSWS; Pa), and m
idwall fractional shortening (MFS; %) were obtained from M-mode images of t
he left ventricle in transthoracic long-axis view and in transesophageal tr
ansgastric view.
Results Coronary flow velocity at baseline was not significantly different
in the three groups, despite significantly higher rate-pressure product (RP
P) in the hypertensive groups as compared with controls. Only in control su
bjects, was resting coronary flow velocity significantly correlated with RP
P (y = 4279 + 200x, r = + 0.58, P < 0.05) and PSWS (y = 17.2 + 5.1x, r = 0.62, P < 0.05). Coronary reserve was 3.5 +/- 0.65 in controls and signific
antly lower (P < 0.05) in borderline hypertensive (2.87 +/- 0.46) and in su
stained hypertensive subjects (2.66 +/- 0.56). Minimum coronary resistance
was significantly increased in both hypertensive groups (1.30 +/- 0.29 and
1.39 +/- 0.48 mmHg/s per cm) as compared to normotensive controls (0.93 +/-
0.20 mmHg/s per cm, P < 0.01).
Conclusions In asymptomatic subjects with borderline hypertension and witho
ut LVH, a significant reduction in coronary flow reserve is already detecta
ble and appears almost entirely related to an impaired coronary vasodilator
capacity rather than to an increased myocardial oxygen demand. J Hypertens
2000, 18:453-459 (C) Lippincott Williams & Wilkins.