Decreased left ventricular contractility reserve in patients with never-treated essential hypertension

1. Left ventricular diastolic dysfunction is often present in patients with essential hypertension. To determine whether left ventricular systolic fun ction is normal or subnormal, we evaluated the global left ventricular cont ractile reserve in patients with untreated essential hypertension. 2. Thirty-one untreated men with essential hypertension and 12 normotensive healthy men were evaluated. Hypertensives were divided into two groups bas ed on the presence (group Hc; n = 21) or absence (group Hn; n = 10) of conc entric left ventricular geometric remodelling, which was defined as a relat ive wall thickness greater than or equal to 0.45 on M-mode echocardiography . We compared echocardiographic data of left ventricular function in hypert ensive men with those in healthy men under beta-adrenoreceptor activation b y up to 10 mu g/kg per min dobutamine infusion. 3. At baseline, endocardial (eFS) and midwall fractional shortening of the left ventricle, the early peak filling velocity (E), the peak late filling velocity (A) and the ratio E/A were similar in the three groups. During dob utamine infusion, eFS was significantly lower in groups Hc and Hn (54.1 +/- 9.2 and 54.1 +/- 7.9%, respectively) than that observed in group N (61.7 /- 7.4%). In addition, eFS was highly correlated with circumferential end-s ystolic wall stress (ESS) during dobutamine infusion in the three groups. I n 11 subjects in group Hc (52%), the eFS-ESS relationship was lower than th e 95% confidence limit of the normal regression. Comparing group Hc with gr oups N and Hn, it was found that E (0.52 +/- 0.12, 0.71 +/- 0.16 and 0.63 /- 0.15 m/s, respectively) and E/A (0.74 +/- 0.23, 1.24 +/- 0.53 and 0.98 /- 0.37, respectively) were significantly lower. 4. Our results suggest that, in addition to diastolic dysfunction, the rese rve of systolic function decreased under beta-adrenoceptor activation in pa tients with essential hypertension.