light headedness and syncope Flashcards
echocardiogram with evidence of right heart strain is ____ but not _____ for PE
suggestive but not definitive
types of orthostatic hypotension syncope
- drug induced
- postural tachycardia syndrome (POTS)
* common in young female assoc with chronic fatigue syndrome and MVP. sx: severe orthostatic intolerance with marked tachycardia - autonomic failure (primary or secondary)
- volume depletion
- sx: hypotension, tachycardia, hx of volume/blood loss, dehydration on exam
most VTE arise from
lower extremity proximal veins (iliac, femoral, popliteal)
unusual causes of nephrogenic diabetes insidious
-hereditary (seen in kids)
-lithium toxicity
-hypercalcemia
(thiazides are a risk)
when to use tilt-table test to assess syncope
- dx vasovagal syncope, or orthostatic hypotension syncope
- avoid in pts with heart DZ
3 types of reflex syncope
- carotid sinus syndrome
- common in elderly male with CAD; brought on by turning head, shaving tight shirt collar; test with carotid massage - situational (brought on by defecation, coughing, GI stimulation, urination, after meals, after exercise)
* will have hx of similar episodes - vasovagal - (brought on by fear, heat, noxious stimuli, pain, stress, i.e SNS)
- prodromal sx (diaphoresis, dizziness, nausea), precipitating factors
tx for hypernatremia
replace free water deficit (encourage water to pt or give IV D5W)
AND failure pts ten to have ____ HTN but ____ when upright
supine HTN , upright hypotension
risk factors for orthostatic hypotension syncope
- elderly
- carotid stenosis
- certain meds (BB, narcotics, alcohol, antidepressants, directics, PDE-I)
how to dx Diabetes insipidus
24 hour urine volume collection confirms presence of polyuria
-usirne osm <300 suggest DI (can’t concentrate it)
-water deprivation test with vasopressin administration
(should increase urine OSM in NL pts or those with central DI, but little/no change if neprhogenic DI)
tilt table testing POTS results
- sustained increased heart rate
- NO hypotension present (no drop in BP)
hypothesized pathophysiology of POTS
1. impaired SNS vasoconstriction --> to venous pooling leading to: -hypovolemia -deconditioning -hyperadrenergic state
T/F compression socks can be used as tx for reflex and orthostatic syncope
yes
three major types of syncope
- cardiac syncope (HIGHEST in SCD)
- reflex syncope (neural mediated- vasovagal)
- orthostatic hypotension syncope
how to tx HCM
-asx pts don’t need tx
-sx patients:
1. BB, or non-dihydropyridine CCB (decrease O2 demand)
2 direuctics (fluid retention)
3. ICD (implantable cardioverter defibrillator) if high risk for SCD
4. severe cases - surgery (septal myomectomy or septal alcohol ablation; mitral valve replacement)
causes of cardiac syncope
structural cardiac dz (AS, HCM, tampondpe, tumor) vascular dz (pulmonary embolism, severe pulm HTN, aortic dissection)
ADH is released in response to
osmotic and non osmotic stimuli
- serum osmolality detected by osmoreceptors in anterior hypothalamus
- decreases in BP or increase in BV detected by baroreceptors in atrium
ADH binds to ___ in the collecting duct and has what effect
binds to V2 receptors and increases cAMP which leads to insertion of AQP2 and urea transporters (INCREASE WATER AND UREA REABSORPTION)
-this is why urea levels go up in dehydration
important questions to ask after a syncope episode
did you have nay jerking? head turning? tongue bitting? post-ictla confusion ? (seizure)
did you have any slurred speech, weakness, difficulty swallowing after? (stroke)
PMH? PSH ?
current meds?
DM? check BG after? (hypo/hyperglycemic)
BP before and after?
PFH?
pharmologic tx for orthostatic hypotension syncope
flurocortisone (aldosterone agonist )
midodrine (alpha Agonist)
caffeine, etc
what causes orthostatic hypotension syncope
NL when standing the decrease preload (degreased BP) to the heart triggers baroreceptor reflex to increase PVR and venous return to increase BP - no syncope
in OHS- autonomic reflex failure or severe intravascular depletion leads to significant drop in BP with postural changes and no reflex increase
tx for DI
central -vasopressin nephrogenic -thiazides -NSAIDS -Vasopressin (bc incomplete resistance)
