ACUTE EFFECTS OF URAPIDIL ON LEFT-VENTRICULAR FUNCTION IN HYPERTENSIVE PATIENTS - COMPARISON WITH CLONIDINE USING RADIONUCLIDE ANGIOGRAPHY

We have studied the effects of urapidil 0.4 mg kg(-1) iv. and clonidin e 2.5 mu g kg(-1) iv. on left ventricular volume and function in 20 pa tients with chronic coronary artery disease and essential hypertension . Patients were studied using (99m)technetium radio nuclide angiograph y with first-pass and ECG-gated equilibrium blood-pool techniques and non-invasive sphygmomanometry. Administration of both urapidil and clo nidine caused a similar decrease in mean arterial pressure (20%), asso ciated with an equivalent reduction in systemic vascular resistance. D espite the decrease in mean arterial pressure, heart rate did nor chan ge after administration of clonidine, but there was an early and trans ient increase of 13% after urapidil There were no changes in cardiac i ndex, but in contrast with clonidine, urapidil caused a decrease in st roke index. in both groups, global left ventricular ejection fraction did not change. Urapidil produced a mean decrease in end-diastolic vol ume of 8% and a mean decrease in end-systolic volume of 13%, in contra st with clonidine which caused little change. Reduced arterial pressur e, systemic vascular resistance and preload after urapidil 0.4 mg kg(- 1) iv., associated with lack of prolonged tachycardia and preserved gl obal left ventricular performance, may have obvious clinical implicati ons in anaesthesia.