Secondary Hypertension

Causes of Secondary Hypertension (the other 5%):

• Renal:
  • Renovascular disease
  • Renal Parenchymal Disease
• Endocrine:
  •  Primary aldosteronism
  • Pheochromocytoma
  • Chronic steroid therapy and Cushing’s syndrome
  • Thyroid or parathyroid disease
• Coarctation of the aorta: narrowing of aorta; mechanical disorder that can be corrected.
• Sleep apnea: blocking of air passages (obesity, etc.) when in a supine position; another mechanical disorder that can be corrected.
• Drug Induced: birth control and chronic use of NSAID’s, Decongestants

Renovascular Disease:

• 1-2% of Hypertension
• Kidneys blood supply is interrupted by narrowing of the renal arteries (stenosis of the arteries)
•  Kidney interprets it as a decrease in cardiac function and releases rennin in an attempt to raise the BP.
•   Renin release leads to the elevation of Aldosterone so that water and sodium are retained.
• This leads to an increase in blood pressure
• Remember the characteristics of this disorder are  increased renin and increased aldosterone.
   

• Mostly seen in old people due to atherosclerosis. 
• When seen in young people it is usually due to thickening of the muscular walls of the vessels.
• Clues to people you might find this disorder in:
  •  People who are resistant to multiple drugs.
  •  People who after many years of controlled Hypertension experience a severe increase in BP.
    •  The old guy who underwent angioplasty who begins to experience uncontrolled Hypertension.
  •  People in which an abdominal bruit is heard. 
  • People that are suffering from renal insufficiency.

Hyperaldosteronism:

• In this case there is no increase in Renin.
• The problem lies with the adrenal.
  • There may be a tumor on the gland that causes an increase in the release of aldosterone.
• The increase in aldosterone causes an increase in sodium level and a decrease in potassium levels.
  • Edema may result (due to water retention)
  • Muscle cramps and palpitations may be seen due to the effects of the ion imbalance
  • BP increases.
• Clues for detection: 
  • Young people with high BP
  •  People with multiple drug resistance
• Test that may confirm suspicions:
  • serum renin/aldosterone
  • CT scan of abdomen to demonstrate adrenal adenoma
• Treatments:
  • Spironolactone: blocks receptors for aldosterone.
  • Removal of the adrenal

Pheochromocytoma:

·         A rare catecholamine producing tumor of  the chromaffin tissues.  Results in release of Norepinephrine and epinephrine.

·         Secretion of the catecholamine is sporadic, so the symptoms seen are very paroxysmal.

• Patient may seem like they are having a panic attack because they suddenly experience increased heart rate , headaches, and flushing.

·         Labs will show increased vanillyl-mandelic acid or metanephrines (metabolites of Norepinephrine and epinephrine.)

·         Treat with alpha and beta blockers

Back to the Circulatory System Index