Secondary Hyperaldosteronism

Secondary hyperaldosteronism is aldosterone excess driven by raised renin and angiotensin II.

• Causes with hypertension: renal artery stenosis, renin secreting tumours (reninoma), malignant hypertension.
• Causes without hypertension: heart failure, cirrhosis with ascites, nephrotic syndrome, Bartter and Gitelman syndromes, diuretic use, volume depletion, pregnancy.
• Consequences: sodium and water retention, potassium loss, metabolic alkalosis.

• Features of the primary condition: oedema, ascites, resistant hypertension, abdominal bruit.
• Hypokalaemia symptoms, hypertension in renovascular disease.
• Normal or low blood pressure in cirrhosis, heart failure, tubulopathies.

• High renin and high aldosterone (ARR low); potassium low, bicarbonate high.
• Search for cause: renal duplex or CT angiography, echocardiography, liver evaluation, urinary protein, urinary electrolytes, diuretic screen.
• Selective renal vein renin sampling for reninoma or functional renal artery stenosis.

• Treat the underlying cause (renal artery angioplasty, heart failure therapy, resection of reninoma).
• Mineralocorticoid antagonists: spironolactone 25 to 100 mg daily (up to 400 mg in cirrhotic ascites), eplerenone, with potassium monitoring.
• ACE inhibitors/ARBs in renovascular hypertension with caution; potassium supplements or amiloride for hypokalaemia.
• Sodium restriction in oedematous states.
• Monitor electrolytes, renal function.