[Importance of measuring blood volume by an isotope method in essential hypertension].

Measurement of the blood volume in cases of essential hypertension has shown a negative correlation with increase in blood pressure. We have been able to distinguish a group of moderate hypertensives who are hypervolemic, and whose systemic effect is more marked than in the moderate hypovolemic type. Such cases respond poorly to single drug therapy with beta blockers, but well to diuretics. The authors propose a general treatment scheme for essential hypertension: single therapy (beta blockers or diuretics) in mild cases of hypertension; single therapy by diuretics in the moderate types with the increased volume; single therapy by beta blockers in the moderate types with low volume, multiple treatment with the drugs together in cases of severe hypertension.