Effects of Coronary Blood Flow on Left Ventricular Function in Essential Hypertensive Patients.

Abstract

To elucidate the mechanism of left ventricular dysfunction associated with left ventricular hypertrophy in hypertension, coronary blood flow (CBF) and left ventricular mass (LVM) were measured in 62 patients with essential hypertension (mean age, 54 ± 13 years) and 22 normotensive control subjects (mean age, 57 + 13 years). According to the indicator fractionation principle, CBF/cardiac output (CO), estimated on the basis of the ratio of myocardial uptake/total injected dose of thallium-201 (% cardiac uptake), was measured. CBF and CBF per 100 g of myocardium (unit CBF) were calculated according to the following formulas: CBF=% cardiac uptake XCO, and unit CBF = (CBF/LVM) X 1 00, where CO and LVM are echocardiographically determined. Midwall fractional shortening (FS) and isovolumic relaxation time (IRT) were calculated as the indices of systolic and diastolic functions. CBF was greater in hypertensives than in controls (218.2+74.0 vs. 187.4+40.4 ml/min, p<0.05), though unit CBF was smaller in hypertensives than in controls (99.1 ±22.0 vs. 141.2±31.6 ml/min/100 g, p< 0.0001). Multiple regression analyses showed that unit CBF was the most potent predictor of both midwall FS and IRT. A positive correlation was found between midwall FS and unit CBF (r=0.669, p<0.0001), and a negative correlation between IRT and unit CBF (r= -0 .579, p < 0.0001). In conclusion, myocardial ischemia reflected by the decrease in unit CBF may be closely related to left ventricular dysfunction in patients with essential hypertension. (Hypertens Res 2000; 23: 239-245)

Carotid Intima-Media Thickness Is Correlated with Impairment of Coronary Flow Reserve in Hypertensive Patients without Coronary Artery Disease

“…In our study, RWT was significantly correlated with-and LVMI tended to correlate with-the CFR, and the basal coronary flow in hypertensive patients was increased to the same degree as in previous studies (10,25). It has been suggested that remodeling of the coronary arterioles, an increase in the extracellular matrix, and increased oxygen demand following established LVH are all strong contributors to the impairment of CFR in patients with hypertension (26,27). However, when the analysis was limited to hypertensive patients in our study, CFR did not correlate with LVMI or RWT.…”

Relations of left ventricular mass and systolic function to endothelial function and coronary flow reserve in healthy, new discovered hypertensive subjects

“…2.7 Our findings showed that lower CFR was significantly and independently associated with lower resting stress-corrected MWS, a measure of myocardial contractility. Previously, it was reported an association of lower MWS with lower resting myocardial blood flow assessed by SPECT, 35 but CFR was not tested. Lower myocardial contractility may be associated with lower coronary blood flow; however, the association of lower resting myocardial contractility to lower CFR by dipyridamole stress testing is new.…”

Effects of Angiotensin II Type 1 Receptor Antagonist on Smooth Muscle Cell Phenotype in Intramyocardial Arteries from Spontaneously Hypertensive Rats

“…Myocardial ischemia reflected by the decrease in unit coronary blood flow might be closely related to LV dysfunction in patients with essential hypertension (3). Angiotensin (Ang) II cardial ischemia (6), and decreasing coronary artery periarteriolar collagen deposition in hypertension (7,8).…”