CHRONIC HEMODYNAMIC-EFFECTS OF CARVEDILOL IN ESSENTIAL-HYPERTENSION AT REST AND DURING EXERCISE

Nineteen men (mean age 44 years) with essential hypertension, WHO stage I, were studied invasively at rest and during exercise. Blood pressure was recorded in intra-arterially (brachial artery), cardiac output by dye dilution method and heart rate by electrocardiography. After initial pre-drug recordings, the patients received 25 mg carvedilol orally and central haemodynamics at rest and during exercise were recorded 1 and 2 h after tablet in take to evaluate the immediate effects of curvedilol. The results indicated a combined β-blocking and vasodilating effect. After 6-9 months of treatment, supine haemodynamics were recorded 12-24 h after the last dose and then 1 and 2 h after an additional 25 mg dose. During chronic treatment (2 h after last dose at rest supine) mean arterial pressure was reduced by 17% (P <0.001) and total peripheral resistance index by 6% (NS) while heart rate and cardiac index were reduced by 12%. Exercise haemodynamics demonstratedafall in bloodpressure of 17% (P <0.001). Exercise stroke index increased by 5% (NS), partly compensatingfor the reduction in heart rate of 17%. Total peripheral resistance index was reduced by 5% (NS). It is concluded that carvedilol is an effective anti-hypertensive agent in a large proportion of patients with essential hypertension. The haemodynamic mode of action reflects an a1-blocking activity, particularly in situations with low sympathetic tone. During exercise the β1-blocking activity (demonstrated by the reduction in heart rate) is more prominent. © 1992 The European Society of Cardiology.