Endocrine HTN (DJ) Flashcards
HTN increases the risk of:
stroke, heart failure, MI, renal failure
Why do we treat essential HTN?
lowering BP = lower risk of diseases associated with HTN
CVA, CHF, MI, RF
How is pre-HTN defined?
SBP = 120-139 DBP = 80-89
*note: these people progress to HTN at a rate of 10%/yr
CV risk is greater in patients with high levels of:
renin
compared to patients with low-renin HTN
BP response to diuretics and CCB’s is better in patients with what type of HTN?
low-renin
BP response to ACEI’s is better in patients with what type of HTN?
high-renin
T/F: Successful trx of essential HTN can be curative
F, trx of the underlying cause of secondary HTN*
What 3 endocrine diseases cause HTN in the majority of patients?
primary hypoaldosteronism
pheochromocytoma
Cushing’s
What are the 2 components of the sympathochromaffin system?
- sympathetic NS (NE)
2. chromaffin tissues, e.g. adrenal medulla (epi)
What is the major end product of catecholamine metabolism? What enzyme produces this?
vanillymandelic acid (VMA) MAO
Because there is a steep concentration gradient for ___, typical plasma levels must be substantially increased to affect BP.
NE
What are pheochromocytoma?
catecholamine-producing tumors comprised of chromaffin cells, which produce labile HTN and paroxysmal symptoms
Why is it important to detect pheochromocytoma?
1) usually curable
2) untreated patients are at risk for a lethal HTN paroxysm
3) 5-10% of them are malignant
4) may be a clue to a familial autosomal dominant syndrome
What malignancies are associated with pheochromocytoma?
multiple endocrine neoplasia:
- -type 2A (hyperparathy + medullary carcinoma of the thyroid)
- -type 2B (multiple mucosal neuromas + medullary carcinoma of the thyroid)
What are 2 conditions that may occur with familial pheochromocytoma?
- von Hippel-Lindau (abn tumor suppression)
2. neurofibromatosis (uncommon)
What clinical symptoms are associated with pheochromocytoma?
- paroxysmal symptoms (HA, diaphoresis, palpitations)
- labile HTN
- family hx
What stimuli may elicit pheochromocytoma symptoms?
positional changes stress abd pressure meds direct pressure applied to tumor
What metabolic features are associated with pheochromocytoma?
increased metabolism
profuse sweating
hyperglycemia
wt loss
What causes glucosuria associated with pheochromocytoma?
catecholamines stimulate hepatic glucose production and inhibition of insulin secretion/action
What hematologic and hemodynamic features are associated with pheochromocytoma?
catecholamine-induced vasoconstriction and plasma volume reduction cause:
- orthostatic hypotension
- elevated hct (volume contraction)
What labs are performed to diagnose pheochromocytoma?
What drug should you use to treat HTN for these labs?
- 24h urine catecholamine (preferred)
- total metanepherines
- plasma catecholamine (but short t1/2)
clonidine–avoid false positives
Where are most pheochromocytoma located?
abdomen (99%) adrenal medulla (90%)
Where are familial pheochromocytoma located?
bilateral adrenals
Treatment of pheochromocytoma?
surgery with pre-op trx with alpha-antagonists (to prevent BP increases during surgery)
