Background: Although a reduction in myocardial blood volume (MBV), an in vivo index of the myocardial microvasculature, measured by myocardial contrast echocardiography in patients with hypertension (HT), can be demonstrated, it is still unknown whether a decreased MBV can be improved by antihypertensive treatment.
Methods and results: Eleven HT patients (mean age 58 years, 7 men) with left ventricular hypertrophy (LVH) and 10 age- and sex-matched normal controls were studied. Harmonic power Doppler images were acquired at end-diastole of every 6(th) beat and MBV was calculated as 10(X/10)x100%, where X (dB) is myocardial contrast intensity minus the contrast intensity of the adjacent intracavity blood pool. Baseline blood pressure (BP) and left ventricular mass index (LVMI) in the HT patients were higher and MBV was lower than in the controls (2.52 +/-0.37% vs 3.31 +/-0.61%, P<0.01). MBV did not correlate with mean BP, but was inversely correlated with LVMI (r=0.61, P<0.01). After treatment with valsartan for 6 months, LVMI significantly decreased and MBV increased (2.72 +/-0.26%, P<0.05 vs baseline) in the patients with HT. There was a significant inverse correlation between the changes in MBV and those of LVMI (r=0.62, P<0.05), but not between MBV and mean BP.
Conclusions: Valsartan, an angiotensin II receptor blocker, corrected the decreased MBV in association with regression of LVH in patients with HT.