Lecture 6: Syncope Flashcards
How long does syncope typically last?
< 1 minute, with full recovery after.
What are the 4 MCC of syncope?
- Reflex syncope
- Orthostatic syncope
- Cardiac arrhythmias
- Structural cardiopulmonary disease
What is reflex syncope?
Upright position resulting in vasodilation.
MC after exercise, defecation/urination, coughing, etc
What can help differentiate a seizure from syncope physically?
Seizures tend to have their eyes open
What is a long QTc?
> = 440ms in men, 460 in women
> 500 is risk of torsades
General rule of thumb: Less than half of preceding RR interval
What drug classes are common for QT prolongation?
- Zofran
- Macrolides
- FQs
What is the exclusion criteria for Canadian Head CT?
- Age > 16
- Pt not on blood thinners
- No seizure after injury
When can you NOT use the canadian syncope risk score?
- LOC > 5 min
- AMS
- Seizure
- Head trauma with LOC
- Intoxication
- Language barrier
San Francisco Syncope Mnemonic
- CHF history
- Hct < 30%
- EKG abnormal
- SOB hx
- SBP < 90 at triage
What makes cardiac syncope more likely?
- Lack of prodrome
- Happens without precipitating event?
- Underlying heart disease
What falls under reflex syncope?
- Vasovagal
- Situational
- Carotid Sinus Syncope
Features of vasovagal syncope
- MC type of syncope overall
- Prodrome usually present
- Occurs either sitting or standing
- Classic: donating blood or emotionally upset
- After vigorous exercise
- Usually a dx of exclusion
What is the underlying pathology of trigger reflex syncope?
Increased parasympathetic activity, slowing the heart.
What is the underlying pathology of orthostatic syncope?
- Change in position causes BP change
- Sympathetic is impaired, so there is a reflexive tachycardic response
Define orthostatic hypotension
Greater than 20 SBP or 10 DBP drop from supine to standing.
Often accompanied by 20 BPM increase as well.
MCC of orthostatic hypotension
- Neurodegenerative
- Neuropathies
- Autoimmune disorder
- Volume depletion
- Medications
- DM
What meds can contribute to orthostatic hypotension?
- Loop diuretics
- alpha-1 adrenergics
- beta-adrenergics
- alpha-2 adrenergics
- Nitric oxide vasodilators
- RAS inhibitors
- CCBs (Non-DHP)
- Dopamine antagonists
- Antidepressants
- SSRIs
- SGLT2i
Who is carotid sinus hypersensitvity MC in?
Older males with atherosclerosis
What is positive carotid syncope?
> 50 SBP drop or symptomatic upon massage
What are the indications for aortic stenosis valve replacement?
- Severe AS with symptomatic
- Severe AS undergoing CABG, aortic, or valve sx
- Severe AS with LVEF < 50%
What must you avoid in the ED for aortic stenosis?
- Non-DHP CCBs
- Preload reducers (Nitro)
What is subclavian steal syndrome?
- Stenosis of subclavian artery
- Decreased perfusion pressure to distal subclavian, so retrograde flow goes into ipsilateral vertebral artery
- Summary: Arm steals blood flow from vertebrobasilar system, causing neurologic and UE symptoms due to arterial insufficiency
What suggest subclavian steal syndrome?
- BP is much lower in the ipsilateral arm
- UE pain, fatigue, coolness, paresthesia
- Right is much more common
Dx of subclavian steal syndrome
- Arterial US or CTA with contrast
Maybe arm, chest, and head
Tx of subclavian steal syndrome
- Statins
- AP/AC therapy
- Smoking cessation
- BP management
Presentation of basilar artery insufficiency
- Head position change can cause symptoms
- Syncope if contralateral side is stenotic
- N/V
- Weakness
- Numbness
- Dysphagia
- Dysarthria
- Syncope
- Vision changes
V similar to stroke
Dx of basilar artery insufficiency
- Glucose
- CT brain w/o con
- CTA Head & neck w/ con
- Full neuro
- HINTS exam (distinguish between central vs peripheral vertigo)
What is the HINTS exam?
- Horizontal Head Impulse Test
- Nystagmus in eccentric gaze
- Test of Skew (Vertical Skew)
when you suspect a posterior stroke
