Predictive value of sympathetic cardiovascular reflexes and urinary catecholamines when selecting patients for antihypertensive treatment with beta-adrenergic blocking drugs.

Two different sympathetic cardiovascular reflexes and the urinary catecholamines were studied to try to predict which patients would respond best to antihypertensive treatment with alprenolol, a beta-adrenergic blocking drug. The antihypertensive effect of sustained release tablets of alprenolol (200 mg twice daily) in 19 young patients with labile hypertension was confirmed. The treatment effectively reduced the tachycardia produced by the Valsalva manoeuvre and by nitroglycerin, and reduced the rise in systolic blood pressure after the Valsalva manoeuvre. The excretion of catecholamines was not affected. Neither the sympathetic cardiovascular reflexes produced by the Valsalva manoeuvre and nitroglycerin nor the excretion of catecholamines revealed which patients would respond best to alprenolol.