iatroX Rounds #1
The clues
- 1
A 48-year-old man is reviewed in the hypertension clinic for persistently high blood pressure readings despite regular medication.
- 2
He notes increasing fatigue and episodes of muscle weakness over the past few months.
- 3
There is no significant past medical history, but his blood pressure remains uncontrolled on three antihypertensive agents including an ACE inhibitor, a calcium channel blocker and a thiazide diuretic.
- 4
On examination, he is hypertensive (BP 172/106 mmHg) but has no peripheral oedema or clinical features of Cushing's syndrome.
- 5
Blood tests show a plasma potassium of 2.7 mmol/L, normal renal function and bicarbonate of 30 mmol/L.
- 6
Plasma aldosterone is raised with suppressed renin activity, and the aldosterone:renin ratio is markedly elevated.
Primary hyperaldosteronism (Conn’s syndrome) is due to excessive secretion of aldosterone, usually from an adrenal adenoma or bilateral adrenal hyperplasia, leading to hypertension and hypokalaemia.
- Resistant hypertension, often in younger adults
- Unexplained hypokalaemia on routine bloods
- Elevated bicarbonate (metabolic alkalosis)
- Suppressed renin with high aldosterone (elevated ARR)
for education and entertainment. not medical advice.