Hyperaldosteronism Flashcards
What is hyperaldosteronism?
Hyperaldosteronism refers to high levels of aldosterone in the body.
What is Conn’s syndrome?
Conn’s syndrome refers to an adrenal adenoma producing too much aldosterone.
How common is hyperaldosteronism in patients with hypertension?
Hyperaldosteronism may be present in 5-10% of patients with hypertension.
What are the key symptoms of hyperaldosteronism?
The key presenting feature is hypertension, with other non-specific symptoms like headaches, muscle weakness, and fatigue.
What is the Renin-Angiotensin-Aldosterone System (RAAS)?
The RAAS regulates blood pressure by releasing renin, which converts angiotensinogen into angiotensin I, which then becomes angiotensin II in the lungs. Angiotensin II stimulates aldosterone release from the adrenal glands.
How does aldosterone affect the kidneys?
Aldosterone increases sodium reabsorption, potassium secretion, and hydrogen secretion in the kidneys’ distal tubules and collecting ducts.
What is primary hyperaldosteronism?
Primary hyperaldosteronism is when the adrenal glands are directly responsible for producing too much aldosterone, leading to low serum renin levels.
What are the causes of primary hyperaldosteronism?
The causes include:
* Bilateral adrenal hyperplasia (most common)
* Adrenal adenoma (Conn’s syndrome)
* Familial hyperaldosteronism (rare)
What is secondary hyperaldosteronism?
Secondary hyperaldosteronism is caused by excessive renin, often due to conditions that lower kidney blood pressure, such as renal artery stenosis, heart failure, or liver cirrhosis.
How is renal artery stenosis confirmed?
Renal artery stenosis can be confirmed with:
* Doppler ultrasound
* CT angiogram
* Magnetic resonance angiography (MRA)
What is the aldosterone-to-renin ratio (ARR)?
The ARR is a screening test for hyperaldosteronism.
* High aldosterone and low renin suggest primary hyperaldosteronism.
* High aldosterone and high renin suggest secondary hyperaldosteronism.
What other investigations are used to diagnose hyperaldosteronism?
Other investigations include:
* Raised blood pressure (hypertension)
* Low potassium (hypokalaemia)
* Blood gas analysis (alkalosis)
* Imaging (CT/MRI) for adrenal tumors or hyperplasia
* Renal artery imaging for renal artery stenosis
What is adrenal vein sampling?
Adrenal vein sampling involves drawing blood from both adrenal veins to locate which gland is producing more aldosterone.
What is the medical treatment for hyperaldosteronism?
The medical treatment includes aldosterone antagonists such as:
* Eplerenone
* Spironolactone
What treatments are available for the underlying cause of hyperaldosteronism?
Treatments include:
* Surgical removal of an adrenal adenoma
* Percutaneous renal artery angioplasty to treat renal artery stenosis
What is an important tip for recognizing hyperaldosteronism?
Hyperaldosteronism is the most common cause of secondary hypertension. It should be tested for in patients who are younger, fail to respond to treatment, or have low potassium, though potassium levels can sometimes be normal.
