Blood pressure during exercise and the effect of hexamethonium.

This paper is concerned with the effect of exercise on the blood pressure and the modification of this effect by hexamethonium bromide. It is well known that the methonium compounds can produce a fall in the blood pressure ofmany hypertensive subjects when lying down. This fall, however, is variable and inconstant. In normal persons, the methonium compounds do not produce a fall in the basal blood pressure taken in the supine position (Conway, 1953). In all persons, normal and hypertensive, methonium compounds produce a postural fall in the blood pressure. This postural hypotension has, for the most part, been regarded as an undesirable side-effect ofmethonium therapy but some have attempted to turn it to good account; for example, the head of the bed has been raised on blocks as a routine part of hexamethonium treatment of hypertension (Shirley Smith, 1953). By taking blood pressure recordings in the lying and standing positions, it was found that hexamethonium bromide had, in many subjects, only a postural effect. If this postural effect was only present when the person was standing still and passed off on exercise-and this seemed a likely a priori supposition-then the postural hypotension would obviously be of no value but merely an unpleasant side-effect likely to cause fainting in the erect position, or even to precipitate thrombosis. If, however, a hypotensive effect persisted on exercise-that is when the patient was upright and about his daily work-then this so-called side-action should constitute a most significant factor in the treatment of hypertension by the methonium compounds. It, therefore, seemed logical to study the effect of exercise on the blood pressure of hypertensive persons before and after treatment with methonium compounds.