Orthostatic Hypotension

Question 1

What is the definition of orthostatic HOTN?

Answer 1

Drop in SBP of at least 20 OR
Drop in DBP of at least 10
Within THREE minutes of standing

If symptoms but no drop = orthostatic intolerance

Question 2

What are the two categories of causes of orthostatic HOTN based on HR?

Answer 2

Non neurogenic = inc HR
Neurogenic = no inc HR

Question 3

What are 6 primary causes of orthostatic HOTN?

Answer 3

Idiopathic
Parkinson’s
MSA
LBD
PSP
Pure autonomic failure

Question 4

What are secondary causes of orthostatic HOTN?

Answer 4

Iatrogenic (drugs)
DM
CVD (AS, CHF, AV block, PHTN, HTN)
CKD
Autoimmune
Endocrine (adrenal insufficiency, thyroid)
Volume depletion
Alcoholic polyneuropathy
Multiple myeloma
Amyloidosis
Multiple sclerosis

Question 5

Causes of non neurogenic orthostatic HOTN

Answer 5

(inc HR)
4 D’s
1. Deconditioning
2. Dysfunctional heart (low EF, AS)
3. Dehydration (disease, dialysis, diuretics, narcotics, digoxin, ABx, CHEI)
4. Drugs (6 antis)
a. AntiHTN
b. Anti ANGINAL
c. Anti PARKINSONIAN
d. Anti DEPRESSANTS
e. Anti PSYCHOTICS
f. Anti BPH (terazosin, tamsulosin)

Question 6

Causes of neurogenic orthostatic HOTN

Answer 6

1. Autonomic dysfunction
   a. Diabetic autonomic neuropathy
   b. Low B12
   c. HypoTSH
   d. Alcohol abuse
   e. Parkinsonism
   f. Amyloid
2. Idiopathic (depleted NE)
3. Drugs (beta blockers)

Question 7

What are the 4 subtypes of OH?

Answer 7

1. Initial - drop >40 with rapid recovery
2. Delayed BP recovery- drop >20 , recovery around 30 seconds
3. Classic - drop >20, no recovery
4. Delayed OH - drop >20 but doesn’t start until 3+ mins

Question 8

What 9 outcomes are OH associated with?

Answer 8

1. Falls
2. Fractures
3. Frailty
4. Syncope
5. Dementia
6. Depression
7. Stroke
8. CVD
9. Mortality

Question 9

Further testing for possible OHOTN or unknown mechanism

Answer 9

Ambulatory BP monitor
Tilt table testing
Active standing test
Autonomic function test

Question 9

Non Pharm management of OHOTN

Answer 9

1. Education - warnings, day schedule, raise HOB, shower chair
2. Medication review
3. Counter maneuvers - cross leg stand/sit, squat stand
4. Drink 500 mL water in 2 mins
5. Frequent small meals
6. Reduce alcohol
7. Salt 10 g/d, fluids 2-3 L
8. Exercise
9. Abdominal binders
10. Avoid heat (day, bath)

Question 10

Pharmacologic tx for OHOTN

Answer 10

1. Fludrocortisone (synthetic mineralocorticoid)
2. Midodrine (direct alpha 1 adrenergic R agonist)
3. Atomoxetine (NE reuptake inh)
4. Pyridostigmine (peripheral CHI)
5. Acarbose (alpha glucosidase inh for post prandial)
6. Caffeine (for post prandial)
7. Droxidopa (synthetic NE precursor)
8. Domperidone (dopamine agonist)

Question 11

What ways can normal aging cause orthostatic HOTN?

Answer 11

1. Decreased baroreceptor sensitivity
2. Diminished thirst response
3. Increased vascular stiffness
4. Decreased vasoconstrictor response to adrenergic stimulation
5. More prone to hypovolemia = unable to conserve water and salt from dec RAAS and impaired skin barrier
6. Relatively fixed heart rate

Question 12

How prevalent is OHOTN?

Answer 12

Community dwelling 60+ = 22.2%
LTC 60+ = 24%

Question 13

Side effects of fludrocortisone

Answer 13

1. CHF
2. Edema
3. HypoK
4. Supine HTN

Question 14

Side effects of midodrine

Answer 14

Supine HTN

Question 15

Side effects of pyridostigmine

Answer 15

N/V
Urinary urgency

Question 16

Side effects of domperidone

Answer 16

Dry mouth
Diarrhea

Question 17

3 clinical features of autonomic failure aside from OHOTN

Answer 17

1. GI - constipation, siallorhea
2. GU - OAB, retention, ED
3. Derm - hypohydrosis