Haemodynamic and pulse wave responses to intravenous infusions of angiotensin II during chronic telmisartan therapy in normal volunteers

Abstract

This study investigated the central haemodynamic, blood pressure (BP) and pulse wave responses to progressively increasing infusion rates of intravenous angiotensin II (Ang II) in normal volunteers during chronic therapy with telmisartan or placebo. Ten normal volunteers, aged 21 33 years, completed a randomised, double-blind crossover study. Ang II was infused intravenously at increasing infusion rates (0 512 ng/minute) at the end of one week of telmisartan therapy (40 80 mg/day) and one week of placebo therapy. BP, central haemodynamics and pulse wave parameters were monitored continuously using a CardioDynamics Recorder, a Pulse Tracer Recorder and a Finipress Recorder. Baseline diastolic BP (57+12 vs. 67+13 mmHg) and pulse wave reflection index (RI) (38.4+18.6 vs. 60.6+12.5%) were significantly lower on telmisartan than on placebo therapy. Cardiac index (CI), systolic BP, systemic vascular resistance index (SVRI), RI and pulse wave stiffness index (SI) were all significantly increased in a dose-dependent manner by Ang II on placebo therapy. Telmisartan significantly (p<0.05) attenuated all of these responses to Ang II. Increases in BP during Ang II infusion were associated with increases in SVRI and CI. Telmisartan effectively blocked the effects of intravenous Ang II on CI, BP, RI and SI in healthy volunteers. Changes in CI make a major contribution to increase in BP response to intravenous Ang II in normal volunteers.