Coronary flow velocity reserve in hypertensive patients with left ventricular systolic dysfunction.
BACKGROUND
Hypertensive microvascular disease is speculated to be a limiting factor for the ability of left ventricular (LV) hypertrophy to maintain LV systolic function in systemic hypertension. The role of coronary reserve, which may be affected by microvascular disease, remains uncertain in the pathophysiology of hypertensive heart disease.


OBJECTIVE
A progressive impairment of coronary flow velocity reserve (CFVR) according to the presence and severity of LV systolic dysfunction is anticipated to occur in hypertension.


METHODS
According to the absence or presence of LV dysfunction (LV fractional shortening - FS% < 30), two groups of hypertensive patients were investigated: HP1 (n = 9, FS% = 36+/-6) and HP2 (n = 13, FS% = 18+/-6). Eight normal subjects (NL) served as controls (LVFS% = 35+/-3). Doppler blood flow velocity was obtained from the left anterior descending coronary artery using transesophageal echocardiography before, and during 6-min continuous adenosine infusion (140 microg x kg(-1) x min(-1) intravenous). The CFVR was calculated as the ratio of maximal to baseline peak diastolic flow velocities.


RESULTS
The comparison among NL, HP1, and HP2 groups showed statistically different (p < 0.05) mass index (101+/-18, 172+/-46, and 257+/-54 g x m(-2)), end-systolic wall stress (76.9+/-14.4, 78.4+/-23.9, and 174.5+/-43.0 10(3) x dyn x cm(-2)), and CFVR (3.5+/-0.6, 3.2+/-0.4, and 2.6+/-0.8), respectively. The CFVR correlated significantly and directly with LVFS% (r = 0.40) and correlated inversely with both mass index (r = -0.54) and end-systolic stress (r = -0.40).


CONCLUSIONS
These results indicate that CFVR impairment is weakly related to LV dysfunction in hypertension.
Pereira
ValériaFontenelleAngelim
V
Heart Institute (InCor), University of São Paulo Medical School, São Paulo, Brazil.
de
CarvalhoFrimmClovis
C
Rodrigues
AnaClaraTude
A
Tsutsui
Jeane Mike
JM
Cúri
Mariana
M
Mady
Charles
C
Ramires
JoséAnonioFranchini
J
D000328:Adult; D000704:Analysis of Variance; D001783:Blood Flow Velocity / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D017548:Echocardiography, Transesophageal; D004562:Electrocardiography; D005260:Female; D006801:Humans; D006973:Hypertension / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D013599:Systole / Q000502:physiology; D014665:Vasodilator Agents / Q000627:therapeutic use; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology*
D014665:Vasodilator Agents