1. Twelve hypertensive patients with cardiomegaly were treated with equivalent antihypertensive doses of prazosin (11 weeks) and β-adrenoceptor-blocking drug (9 weeks) in random crossover fashion. 2. At the end of each treatment period haemodynamic assessment included the response to isometric handgrip exercise (4 min at 30% of maximum voluntary contraction). 3. Resting cardiac index and heart rate were higher on prasozin although the latter was only 65 beats/min. Systemic vascular resistance and left ventricular filling pressure were insignificantly higher on β-adrenoceptor-blocking drug. 4. During isometric handgrip the blood pressure rise was similar on the two regimens, but the mechanism whereby it was achieved was quite different. On prazosin an increase in cardiac output accounted for the pressor response with virtually no change in systemic vascular resistance, whereas on β blockade there was a flat cardiac output response with a marked increase in the systemic vascular resistance. 5. Ventricular function curves indicated a predominant utilization of the Frank-Starling mechanism during β blockade, whereas enhanced contractility played a major role during prazosin treatment. 6. The isometric exercise response pattern during prazosin treatment resembles that in normal subjects whereas in the β blockade phase it corresponded to that in untreated hypertensive patients with left ventricular hypertrophy or cardiomegaly or to that in congestive heart failure patients. 7. There was no evidence of harmful effects of combined pre- and after-load reduction in hypertensive patients with cardiomegaly and normal filling pressure, even under conditions of moderately severe cardiac loading with isometric exercise.
1. Haemodynamic and left ventricular variables were determined by M-mode echocardiography in 21 normotensive and 36 hypertensive patients during the last trimester of pregnancy. 2. Blood pressure of hypertensive patients was lowered by bed rest only, or by oxprenolol or methyldopa, but remained elevated. 3. Cardiac output was raised in the last trimester of pregnancy in both normotensive and hypertensive patients. 4. Left ventricular mass was increased in normal pregnancy, but displayed an exaggerated increase in hypertensive patients. 5. Total peripheral resistance was inappropriately elevated in hypertensive pregnancy, except in the oxprenolol-treated group. 6. There was no reduction in heart rate or cardiac output in the group treated with β - adrenoreceptor blocking agents. These factors, in combination with normal peripheral resistance, may contribute to the improvement in foetal outcome described in maternal hypertension of pregnancy treated with oxprenolol.
1. A comparison of direct measurement and M-mode echocardiography in the determination of posterior left ventricular wall thickness was performed in 26 subjects, of whom 21 underwent cardiac bypass surgery; the remainder came to necropsy. 2. In the surgical group a close correlation was demonstrated between direct measurement of posterior wall thickness and the echocardiographic end-diastolic dimension ( r = 0·76, P < 0·001). 3. The necropsy measurement of posterior wall thickness correlated with the echocardiographic end-systolic dimension ( r = 0·99, P < 0·001). 4. These findings confirm that the echocardiographic measurement of posterior wall thickness accurately reflects the anatomical dimension.
1. The haemodynamic response to antagonistic (10 μg min −1 kg −1 ) and agonistic (40 μg min −1 kg −1 ) doses of saralasin was studied in young essential hypertensive patients. Blood pressure behaviour alone was thought to be inadequate to describe the response pattern. 2. Pre-saralasin setting of the renin-angiotensin axis was varied with salt intake (15 and 290 mmol of Na + /day) each for 10 days. This failed to influence blood pressure or plasma volume. 3. Antagonist blockade after low salt lowered blood pressure in three patients with the highest plasma renin values. Cardiac output rose in two of these, but it dropped in all others. 4. Decreases in cardiac output occurred with both doses of saralasin and even with suppression of the renin-angiotensin axis. This response is therefore unlikely to be due to removal of myocardial or venous angiotensin effects. 5. The renin-angiotensin system played a part in maintenance of blood pressure only with severe salt restriction and in a small proportion of cases. 6. No heart rate effect was seen with saralasin. 7. Blood pressure and total peripheral resistance responses were dependent on pre-(antagonist/ agonist) setting, but heart rate and cardiac output were not influenced by this factor.
1. A questionnaire, modified from Bulpitt & Dollery (1973), inquired about 20 symptoms commonly associated with hypertension or its drug therapy in 1017 subjects (age 30–69 years). Groups consisted of ( a ) active therapy, ( b ) placebo, ( c ) no tablets, and ( d ) a non-study control group. The response rate was 96% in the first three groups and 92% in group ( d ). 2. The subjects in groups ( a ), ( b ) and ( c ) constituted part of a placebo-controlled, patient-blind intervention study in the treatment of mild hypertension (The Australian National Blood Pressure Study). 3. After age/sex adjustment of the data, only sleepiness and self-assessed depression were found to be more common in the actively treated group. Impotence, failure of ejaculation and nocturia were age-related symptoms. Generally, complaint rate was higher in females. 4. The knowledge of a mild hypertensive condition or its modern drug therapy lead to very few symptoms in a non-hospital population who already have a fairly high ‘complaint level’.
1. A highly significant inverse relationship was found between blood pressure in untreated hypertensive subjects in late pregnancy and birth weight. 2. Reversal of this intrauterine growth retardation was achieved in 19 patients by treatment of hypertension with oxprenolol. 3. No adverse effects from oxprenolol were found in the patients or in their babies.