Hypertension of Renal Origin in Childhood.

A persistently raised blood pressure is uncommon in children. Essential hypertension is rare, only a few cases having been recorded (Court, 1941). Endocrine causes, such as the hyperadrenalism of phaeochromocytomata (Snyder and Vick, 1947) are also uncommon. Elevation of the systolic pressure occurs in diseases of the heart and great vessels, being most notable in coarctation of the aorta and in severe degrees of aortic incompetence. The majority of cases of hypertension, however, are associated with renal disease. It had been realized for many years that some connexion existed between renal disease and hypertension. Bright noted the cardiac hypertrophy of renal disease in 1838. How renal disease could affect the blood pressure was not apparent until Goldblatt et al. (1934) showed that in rabbits a pressor substance is liberated from kidneys to which the blood supply has been reduced. This work has since been developed and extended to other animals, and it is thought probable that the findings are applicable also to man, although this has not been proved conclusively. Butler (1937) was the first to employ nephrectomy deliberately for the relief of hypertension in a child, although Quinby in 1923 found a fall of blood pressure in a case from which a diseased kidney had been removed. Since then many similar operations have been undertaken. Recently Trueta et al. (1947) have put forward their views on the possible role of the kidney in essential hypertension and in the hypertension of chronic renal disease. The experiments of Goldblatt et al. and their subsequent elaboration by others have shown the probable mode of production of hypertension in many cases in which there is an organic cause, whereas Trueta and his colleagues describe a possible mechanism in cases in which organic change is absent at the onset of hypertension and only develops later in the disease.