Haemodynamic studies in hypertensive patients treated by oral proranolol

Haemodynamic studies have been performed in 9 patients whose blood pressures had been satisfactorily controlled with oral propranolol for 7 to 29 months. A postural drop of blood pressure or a fall of blood pressure on exercise did not occur. Pulse rate and cardiac output were below normal at rest and on exercise; peripheral resistance was high. The results are similar to those obtained in a comparable group of hypertensives after acute administration of propranolol. These findings are discussed in relation to the mode of action of propranolol in hypertension.