1. Doppler echocardiographic indices of diastolic function and systemic haemodynamics were studied in response to infusions of angiotensin II (1, 2, 5 and 10 ng min−1 kg−1), D-aldosterone (2, 4, 10 and 20 ng min−1 kg−1) and placebo [0.9% (w/v) NaCl] in ten normal male subjects.
2. Dose-related increases in systolic and diastolic blood pressure were observed with angiotensin II infusion at rates of 2 ng min−1 kg−1 and above, whereas no changes in blood pressure occurred with D-aldosterone. No changes in aortic stroke distance or heart rate were seen with either angiotensin II or aldosterone infusion.
3. Compared with placebo, angiotensin II infusion produced a dose-related prolongation of the isovolumic relaxation time [mean and 95% confidence intervals 12.0 (8.2–15.8) ms, P < 0.001] at 10 ng min−1 kg−1, and a significant reduction in the ratio between early and late transmitral flow velocity integrals at 2 ng min−1 kg−1, [−0.84 (−1.63 to −0.05), P < 0.05] and 5 ng min−1 kg−1 [−0.76 (−1.47 to −0.05), P < 0.05]. No changes in Doppler echocardiographic indices of diastolic function were observed with D-aldosterone infusion.
4. These data suggest that angiotension II, even at a sub-pressor concentration, produces an impairment of left ventricular diastolic filling, which occurs independently of its effect on aldosterone release.
