The development of coronary insufficiency during prolonged treatment of essential hypertension.

The occurrence of signs of coronary insufficiency during prolonged combined treatment of essential hypertension was analysed in a selected group of 42 patients with left ventricular myocardial hypertrophy. During a four-year antihypertensive therapy 17% of patients developed angina pectoris on effort myocardial infarction occurred in 7%, and ischaemic ECG changes during bicycle ergometry or transoesophageal atrial pacing were detected in 36%. In the subgroup with an insufficient hypotensive effect and sustained severe myocardial hypertrophy the signs of coronary insufficiency occurred in 53%. Nevertheless, the attainment of a stable pressure normalization and regression of myocardial hypertrophy does not exclude the development of coronary insufficiency, even in patients treated with beta-adrenoblocking drugs.

Haemodynamic resistance of forearm vessels during prolonged drug treatment of essential hypertension.

In 40 patients with essential hypertension, the authors studied the haemodynamic resistance in forearm vessels before and after 15-min arterial occlusion, and changes in this parameter during a three-year combined antihypertensive treatment. The study revealed that the 15-min occlusion did not entirely suppress the contractile activity of vascular smooth muscles. Under these conditions, the minimum vascular resistance reflects the sum of structural and functional alterations. The character of change in minimal haemodynamic vascular resistance depends on the mechanism of action of the antihypertensive drugs. Administration of the post-synaptic alpha-adrenergic blocker Pratsiol produces a decrease in the minimal haemodynamic vascular resistance.