Abstract
This study was conducted to quantify coronary blood flow (CBF) noninvasively according to the fractionation principle and to elucidate the relation between CBF and left ventricular hypertrophy. CBF/cardiac output (CO), estimated on the basis of the ratio of myocardial uptake/total injected dose of thallium-201(% cardiac uptake), was determined in 14 control subjects and 40 patients with essential hypertension. CBF and CBF per 100g of myocardium (unit CBF) were calculated according to the following formulas: CBF=% cardiac uptake×CO, and unit CBF=(CBF/LVM)×100, where CO and left ventricular mass (LVM) are echocardiographically determined. There was good reproducibility of % cardiac uptake (r=0.983, p<0.0001). Percent cardiac uptake was greater in hypertensive patients (4.65±1.44%) than in control subjects (3.64±0.64%), and there was a positive correlation between % cardiac uptake and LVM. CBF (ml/min) was greater in hypertensive patients (240.7±80.5) than in control subjects (194.9±36.9), but unit CBF (ml/min/100g) was less in hypertensive patients (102.2± 26.7) than in control subjects (150.3±30.5). Multiple regression analyses showed that LVM was the most potent independent predictor of resting CBF in hypertension. Our results indicate that CBF, determined by thallium-201 myocardial scintigraphy, increases parallel to the increase in LVM, but unit CBF decreases even in the resting condition in patients with essential hypertension. (Hypertens Res 1998; 21: 227-234)
