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

Abstract

Introduction

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.

Materials and methods

Ten normal volunteers, aged 21—33 years, completed a ramdomised, 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 continuous using a CardioDynamics Recorder, a Pulse Tracer Recorder and a Finipress Recorder.

Results

Baseline diastolic BP (5712 v G s. 67±13 mmHg) and pulse wave reflection ndex (RI) (38.4±18.6 vs. 60.6±12.5%) were significantly lower U 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.

Conclusions

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.

Keywords

telmisartan angiotensin II haemodynamics pulse wave CardioDynamics Recorder Pulse Tracer recorder

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References

Omvik P. , Gerdts E. , Myking OL , Lund-Johansen P. Long term central hemodynamic effects at rest and during exercise in essential hypertension. Am Heart J 2000 ;140:624-30.

Grossman E. , Peleg E. , Carroll J. , Shamiss A. , Rosenthal T. Hemodynamic and humoral effects of the angiotensin II antagonist losartan in hypertension. Am J Hypertens 1994;7:1041-4.

Rehman A. , Rahman AR , Rasool AH Effect of angiotensin II on pulse wave velocity in humans is mediated through angiotensin type 2 receptors. J Human Hypertens 2002;16: 261-6.

Sageman WS , Riffenburgh RH , Spiess BD Equivalence of bioimpedance and thermodilution in measuring cardiac index after cardiac surgery. J Cardiothorac Vasc Anesthes 2002;16:8-14.

Albert NM , Hail MD , Young JB Equivalence of bioimpedance and thermodilution in measuring cardiac output and index in patients with advanced, decompensated chronic heart failure hospitalized in critical care (abstract). J Am Coll Cardiol 2003;41(suppl):211A.

Verhoeve PE , Cadwell CA , Tsadok S. Reproducibility of ioninvasive bioimpedance measurements of cardiac function (abstract). J Card Fail 1998:4(suppl):53.

Millasseau SC , Kelly RP , Ritter JM , Chowienczyk PJ Determination of age-related increases in large artery stiffness by digital pulse contour analysis. Clin Sci 2002;103:371-7.

Chowienczyk PJ , Kelly RP , MacCallum H. et al. Photoplethysmographic assessment of pulse wave reflection. Blunted response to endothelium dependant beta2 adrenergic vasodilation in type II diabetes mellitus. J Am Coll Cardiol 1999;34:2007-14.

Lokhandwala MF , Amelang E. , Buckley JP Facilitation of cardiac sympathetic function by angiotensin II: role of pre-synaptic angiotensin receptors . Eur J Pharmacol 1978; 52:40509.

10.

ScottAL , Chang RS , Lotti VJ , Siegl PK Cardiac angiotensin receptors: effects of selective angiotensin II receptor antagonists, DUP 753 and PD 121981, in rabbit heart. J Pharmacol Exp Ther 1992;261:931-5.

11.

Feolde E. , Vigni P. , Frelin C. Angiotensin AT1 receptors mediate a positive inotropic effort of angiotensin II in guinea pig atria.EurJPharmacol 1993;245:63-6.

12.

Holubarsch C. , Hasenfuss G. , Schmidt-Schweda S. et al. Angiotensin I and II exert inotropic effects in atrial but not ventricular human myocardium. An in vitro study under physiological study conditions. Circulation 1993;88:1228-37.

13.

Holubarsch C. , Schmidt-Schweda S. , Knorr A. et al. Functional significance of angiotensin receptors in human myocardium. Significant differences between atrial and ventricular myocardium. Eur Heart J 1994;15(suppl D):88-91.