Conn's Syndrome
Key Facts
Symptoms
Diagnosis
Treatment
Primary hyperaldosteronism - excess production of aldosterone, independent of the renin-angiotensin system
- Results in increased sodium and thus water retention (resulting in increased BP) and decreased renin release
- K loss
- Combination of hypokalaemia and hypertension
Conn’s syndrome is due to a adrenal adenoma that secretes aldosterone
Often asymptomatic
Hypertension
- Due to an increase in blood volume
- Can be severe and is associated with renal, cardiac and retinal change
- May not always be present
Hypokalaemia
- Weakness/cramps
- Paraesthesia
- Polyuria
- Polydipsia
Hypokalaemic ECG
- Flat T waves
- ST depression
- Long QT
Serum hypokalaemia
- Not always present
Plasma aldosterone: renin ratio (ARR)
- Initial screening test
- Spirolactone and epiereone should be stopped 6 weeks before test
- Aldosterone is much higher - NOT DIAGNOSTIC, used mainly for screening
CT or MRI adrenals to differentiate adenomas from hyperplasia
Laparoscopic adrenalectomy
Aldosterone antagonist e.g. ORAL SPIRONOLACTONE for 4 weeks pre-op to control BP and K
Epidemiology
Rare condition accounting for <1% of all hypertension
Aetiology
2/3rds - adrenal adenoma that secretes aldosterone - Conn's syndrome
1/3rd - bilateral adrenocortical hyperplasia
Risk Factors
Pathophysiology
Hypertension in patients
With hypokalaemia before diuretic therapy
Resistant to conventional antihypertensive therapy e.g. more than 3 drugs
With accelerated (malignant) hypertension
With unusual symptoms e.g. sweating attacks or weakness
Under 35yrs with no family history of hypertension
Disorder of the adrenal cortex characterised by excess aldosterone production leading to Na and water retention and K loss, and the combination of hypokalaemia and hypertension due to aldosterone producing carcinoma
Differential Diagnosis
Must be differentiated from secondary hyperaldosteronsim which arises when there is EXCESS RENIN which stimulates aldosterone release
Caused by reduced renal perfusion which can be due to:
Diuretics
Congestive cardiac failure
Accelerated hypertension
Hepatic failure
Renal artery stenosis
Increased plasma aldosterone levels that are not suppressed with 0.9% saline infusion - DIAGNOSTIC