Hypertension (Week 11) Flashcards
Blood pressure categories (new guidlines)
what is Essential Hypertension?
hypertension of unknown cause; diagnosis of exclusion
most common form of HTN
40-60 yo
Causes of Secondary Hypertension (that we need to know)
primary hyperaldosteronism
pheochromocytoma
renovascular (renal artery stenosis, fibromuscular dysplasia)
coarctation of aorta
genetics
drugs
approach to essential hypertension
since cause is unknown can’t address the cause; approach is to address lifestyle changes
Medicationts to Use in Hypertension
Start with step 1 and add as needed
- ACE inhib/ARB, Thiazide, and/or Ca2+ channel blocker
- beta blocker
- Thiazide –> Loop Diuretic
- add alpha blocker
- minoxide, clonidine, hydralazine
examples of calcium channel blockers
Nifedipine, Amlodipine
normal kidney size
10 - 12 cm
renin and aldosterone levels in hyperaldosteronism
renin is normal and aldosterone is high
plasma aldosterone >15
ratio of aldosterone:renin >20
testing for primary hyperaldosteronism
aldosterone:renin ratio
correct potassium levels (can skew aldosterone)
imaging to look for mass on adrenal gland or bilateral hyperplasia
treatment of primary hyperaldosteronism
spironolactone, eplerenonne, amiloride (blocks enac), ACE inhib
effects of B Blockers (B1)
- decrease HR
- decrease contractility
- decrease renin production (binds JG apparatus)
- decrease sympathetic outflow
what does carvedilol block?
both alpha and beta receptor
What is Minoxidil?
potent vasodilator
activates K+ channels to cause K+ efflux – hyperpolarization and relaxation of smooth muscles
side effects of Minoxidil
edema – must be on diuretic when taking minoxidil
hair growth
What is Renal Artery Stenosis (RAS)?
narrowed artery causes decreased flow; kidney thinks theres less volume and increases renin release
RAAS –> sodium retention
causes of secondary hypertension
differential for atherosclerotic renal artery stenosis
- Age >50 years
- Other cardiovascular risk factors
- May have a decrease in renal function
- Absent Pulses
- Abdominal Bruit
- US shows unequal kidney size
- Bland urinalysis
- Flash pulmonary edema
Treatment for RAS (renal artery stenosis)
ACE inhibitor or ARB (also helps with cardio risk)
could use angioplasty – unsure of effectiveness
could use antiplatelet drugs, lower lipid
effects of ACE inhibitor
vasodiltion of efferent arteriole = decreased GFR
stops aldosterone cascade
increase in K+ and creatine (need to check that these don’t get too high)
breaks down bradykinin into metabolite that can cause cough and angioedema
at what BP is there end organ damage present
>180/120
Assessment of hypertensive emergency
CNS: Encephalopathy or stroke with deficits. Headaches, nausea, vomiting
CVS: Pulmonary edema, aortic dissection, MI, or angina
Kidney: AKI
Liver: Elevated enzymes
Eyes: blindness
emergency treatment of hypertensive emergency
give rapid vasodilators
goal: decrease blood pressure by 25% to avoid ischemia
(body is adjusted to the high blood pressure; need to decrease gradually to avoid ischemia)
fibromuscular dysplasia as cause of hypertension
- Carotid and renal arteries affected
- Medial layer with dysplasia
treatment of fibromuscular dysplasia causing hypertension
ACE inhibitor / ARB
angioplasty
What is Pheochromocytoma
Secretory tumor of Neurochromaffin cells in adrenal medulla
–> Catecholamine hypersecretion
Symptoms of Pheochromocytoma
Headache, sweating, tachycardia, paroxysmal hypertension, orthostatic hypotension
Screening for Pheochromocytoma
Urine and plasma catecholamine levels
testing for Metanephrine/ Normetanephrine levels
(most stable than epi and norepi and represent epi and norepi levels)
Do Clonidine Suppression Test
Clonidine Suppression Test
Hold antihypertensives
Give clonidine
catecholamine levels should fall
Imaging and Treatment of Pheochromocytoma
Imaging: give epinephrine analog MIBG that can light up tumor
Treatment: surgical removal of the tumor
Mechanism and Effect of Clonidine
Mechanism: Stimulate the central postsynaptic alpha2 receptor in brainstem – decreasing peripheral SNS activity
Effect: Lower norepinephrine levels § Vasodilation
Side Effects of Clonidine
Fatigue/sedation
Dry Mouth
Rebound Hypertension (Wean this to off when stopping)
Lower lipids
Lower glucose levels
disadvantages of taking Clonidine
short-acting so patient has to take a few per day; can’t miss pills or patient can get rebound hypertension
Coarctation of Aorta as cause of hypertension
- congential narrowing of aorta
- diagnosis before age 40
- patient shows hypertension in arms but not legs
diagnosis of coarctation of aorta
aortic imaging – looks like backwards 3 and could see rib notching from increased pressure in internal intercostal artieries
Treatment of Coarctation of Aorta
surgery
good job! you’re done :]
yay hypertension
