Lecture 6: Syncope

Question 1

How long does syncope typically last?

Answer 1

< 1 minute, with full recovery after.

Question 2

What are the 4 MCC of syncope?

Answer 2

1. Reflex syncope
2. Orthostatic syncope
3. Cardiac arrhythmias
4. Structural cardiopulmonary disease

Question 3

What is reflex syncope?

Answer 3

Upright position resulting in vasodilation.

MC after exercise, defecation/urination, coughing, etc

Question 4

What can help differentiate a seizure from syncope physically?

Answer 4

Seizures tend to have their eyes open

Question 5

What is a long QTc?

Answer 5

> = 440ms in men, 460 in women

> 500 is risk of torsades

General rule of thumb: Less than half of preceding RR interval

Question 6

What drug classes are common for QT prolongation?

Answer 6

• Zofran
• Macrolides
• FQs

Question 7

What is the exclusion criteria for Canadian Head CT?

Answer 7

1. Age < 16
2. Pt on blood thinners
3. Seizure after injury

Question 8

When can you NOT use the canadian syncope risk score?

Answer 8

• LOC > 5 min
• AMS
• Seizure
• Head trauma with LOC
• Intoxication
• Language barrier

Question 9

San Francisco Syncope Mnemonic

Answer 9

• CHF history
• Hct < 30%
• EKG abnormal
• SOB hx
• SBP < 90 at triage

CHESS

Question 10

What makes cardiac syncope more likely?

Answer 10

• Lack of prodrome
• Happens without precipitating event
• Underlying heart disease

Question 11

What falls under reflex syncope?

Answer 11

• Vasovagal
• Situational
• Carotid Sinus Syncope

Question 12

Features of vasovagal syncope

Answer 12

• 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

Question 13

What is the underlying pathology of trigger reflex syncope?

Answer 13

Increased parasympathetic activity, slowing the heart.

Question 14

What is the underlying pathology of orthostatic syncope?

Answer 14

• Change in position causes BP change
• Sympathetic is impaired, so there is a reflexive tachycardic response

Question 15

Define orthostatic hypotension

Answer 15

Greater than 20 SBP or 10 DBP drop from supine to standing.

Often accompanied by 20 BPM increase as well.

Question 16

MCC of orthostatic hypotension

Answer 16

• Neurodegenerative
• Neuropathies
• Autoimmune disorder
• Volume depletion
• Medications
• DM

Question 17

What meds can contribute to orthostatic hypotension?

Answer 17

• Loop diuretics
• alpha-1 adrenergics
• beta-adrenergics
• alpha-2 adrenergics
• Nitric oxide vasodilators
• RAS inhibitors
• CCBs (Non-DHP)
• Dopamine antagonists
• Antidepressants
• SSRIs
• SGLT2i

Things that vasodilate or lower volume

Question 18

Who is carotid sinus hypersensitivity MC in?

Answer 18

Older males with atherosclerosis

Secondary: neck abnormalities or tumors in the carotid sinuses

Question 19

What is positive carotid syncope?

Answer 19

> 50 SBP drop or symptomatic upon carotid massage

Question 20

What are the indications for aortic stenosis valve replacement?

Answer 20

• Severe AS with symptomatic
• Severe AS undergoing CABG, aortic, or valve sx
• Severe AS with LVEF < 50%

Question 21

What must you avoid in the ED for aortic stenosis?

Answer 21

• Non-DHP CCBs
• Preload reducers (Nitro)
• BBs

Question 22

What is subclavian steal syndrome?

Answer 22

• 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

Question 23

What presentation suggests subclavian steal syndrome?

Answer 23

• BP is much lower in the ipsilateral arm
• UE pain, fatigue, coolness, paresthesia
• Right is much more common

Question 24

Dx of subclavian steal syndrome

Answer 24

• Arterial US or CTA with contrast

Maybe arm, chest, and head

Question 25

Tx of subclavian steal syndrome

Answer 25

* Statins * AP/AC therapy * Smoking cessation * BP management | Tx of stenosis

Question 26

Presentation of basilar artery insufficiency

Answer 26

* **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

Question 27

Dx of basilar artery insufficiency

Answer 27

* Glucose * CT brain w/o con * CTA Head & neck w/ con * Full neuro * **HINTS exam (distinguish between central vs peripheral vertigo)** ## Footnote HI abnormal = peripheral N unidirectional horizontally = peripheral TS no skew = peripheral

Question 28

What is the HINTS exam?

Answer 28

* Horizontal Head Impulse Test * Nystagmus in eccentric gaze * Test of Skew (Vertical Skew) | when you suspect a posterior stroke ## Footnote This differentiates between central and peripheral vertigo, since central vertigo etiologies are much worse.