Endocrine - Hyperaldosteronism Flashcards
What is the difference between hyperaldosteronism and Conn’s syndrome?
Hyperaldosteronism
- Refers to high levels of aldosterone
Conn’s syndrome
- Adrenal adenoma too much aldosterone
Outline RAAS
Renin produced by juxtaglomerular cells in afferent arterioles in response to low BP
Renin converts angiotensinogen to angiotensin I in the liver
Angiotensin I converted to angiotensin II in the lungs aided by ACE (can still convert without ACE)
Angiotensin II stimulates aldosterone release
What is primary hyperaldosteronism?
Adrenals glands produce too much aldosterone
Low serum renin as high BP supresses
Give 3 causes of hyperaldosteronism
- Bilateral adrenal hyperplasia (most common)
- Adrenal adenoma (Conn’s syndrome)
- Familial hyperaldosteronism
What is secondary hyperaldosteronism?
Excessive renin causing excessive aldosterone production
Renin released due to disproportionately lower BP in kidneys due to:
- Renal artery stenosis
- Heart failure
- Liver cirrhosis and ascites
How is renal artery stenosis diagnosis confirmed?
Doppler ultrasound
CT angiogram
MRA
What investigations are used for hyperaldosteronism?
Aldosterone-to-renin ratio (ARR)
Primary hyperaldosteronism
High aldosterone and low renin
Secondary hyperaldosteronism
High aldosterone and high renin
What investigations should be done to identify the underlying cause of hyperaldosteronism?
- CT or MRI to look for adrenal tumour or adrenal hyperplasia
- Renal artery imaging for renal artery stenosis
- Adrenal vein sampling to locate which gland is producing more aldosterone
How is hyperaldosteronism managed?
Aldosterone antagonists
- Eplerenone
- Spironolactone
Underlying cause
- Surgical removal of adrenal adenoma
- Percutaneous renal artery angioplasty
What is the most common cause of secondary hypertension?
Hyperaldosteronism
Younger patients
Failure to respond to treatment
Low potassium (can be normal in hyperaldosteronism)
