Part of “CHAPTER 80 – HYPERALDOSTERONISM“

A variety of disorders of the kidney, heart, liver, and gastrointestinal tract may lead to hyperreninemia and, in turn, to hyperaldosteronism and hypokalemia. Because the blood pressure may be either normal or high, the disorders may be grouped on the basis of blood pressure.

Disorders that may give rise to hypertension with secondary hyperaldosteronism are renal artery stenosis (see Chap. 82), renin-secreting tumor (see Chap. 219), malignant hypertension, and chronic renal disease (see Table 80-1). Occasionally, the renal disorder may not be apparent clinically, and the hypertension and hypokalemia may be mistaken for primary aldosteronism. Determination of plasma renin activity after overnight bedrest and after ambulation for 2 hours should demonstrate whether this hormone is suppressed or stimulated and make the distinction between primary and secondary hyperaldosteronism. In chronic renal disease with renal insufficiency, plasma renin activity may be increased or suppressed. If it is suppressed, aldosterone also tends to be suppressed, except when the potassium concentration is high. Patients with hyperreninemia, hyperaldosteronism, and hypertension should be evaluated carefully for renal artery stenosis or renin-secreting tumor because these causes of hypertension may be curable.61,62 Sampling of renal venous blood for the determination of plasma renin activity usually indicates whether the increase in renin release is bilateral or unilateral and, if it is unilateral, which kidney is the source.61 Arteriography then can be performed to identify the nature of the disorder and confirm its location.