[Diagnosis of primary hyperaldosteronism. Apropos of 3 cases].

Primary hyperaldosteronism (HA1) represent a rare etiology of arterial hypertension (less than 1%). It concerns, most of the time, aldosterone-producing adenomas or bilateral adrenal hyperplasias although intermediate forms have been reported. The diagnosis of HA1 is based on simple examinations, especially systematic measurement of kaliemia in every hypertensive patient with a normal sodium diet before treatment. The elevation of aldosterone blood levels associated with a low plasma renin activity confirms the autonomous nature of the hormonal secretion which is dissociated from the renin-angiotensin system. Study of the ratio aldosterone blood level/ARP and the captopril test are particularly useful in borderline cases. Once the diagnosis of HA1 is made, a topographic analysis may be undertaken; tomodensitometry and adrenal scintigraphy are currently the examinations of choice in the diagnosis of adrenal tumors. Due to biological, morphological and topographic factors, aldosterone-producing adenomas may be identified with a great deal of certainty: surgical excision ensures a cure in a large majority of cases. The treatment of bilateral hyperplasias remains medical.