Syncope

Question 1

Syncope
Definition

Answer 1

sudden and transient loss of consciousness and loss of postural
tone accompanied by a rapid return to baseline

Question 2

Syncope
Pathophysiology

Answer 2

dysfunction of both cerebral hemispheres or the
brainstem (reticular activating system) usually from hypo-perfusion

Question 3

Syncope
Differential Diagnosis Cardiac

Answer 3

Rhythm Disturbances: dysrhythmias, pacemaker issues
Structural: outflow obstruction (aortic stenosis, HOCM), MI
Other CV diseases: dissection, cardiomyopathy, PE

Question 4

Syncope
Differential Diagnosis Non Cardiac Reflex (neurally mediated)

Answer 4

Vasovagal: sensory or emotional
reactions
Orthostatic: postural, dehydration
Situational: coughing, straining
Carotid sinus pressure: shaving
Subclavian steal: arm exercises

Question 5

Syncope
Differential Diagnosis Non Cardiac Medications

Answer 5

CCBs, β-blockers, digoxin, insulin
QT prolonging meds
Drugs of abuse

Question 6

Syncope
Differential Diagnosis Non Cardiac Focal CNS Hypoperfusion

Answer 6

Hypoxia
Epilepsy
Dysfunctional brainstem

Question 7

Syncope
Investigations
Labs

Answer 7

CBC
CMP
Glucose
BUN/Cr
CK/TnI
β-hCG

Question 8

Syncope
Investigations
HEARTS

Answer 8

Heart rate/rhythm: Tachyarrhythmia, bradyarrhythmia

Electrical conduction: PR (WPW, AV block), BBB and bifasicular block, long QT

Axis: Bifasicular block, new right axis from PE

R-wave progression: Early from WPW type A, late from cardiomyopathy

Tall/small voltages: Small (pericardial effusion), large (HCM, AS)

ST/T changes:PE, STEMI, Brugada, ARVD

Question 9

Syncope
Management
General

Answer 9

ABCs, monitors, oxygen, IV access

Question 10

Syncope
Management
Cardiogenic

Answer 10

Consult cardiology for workup +/- permanent pacemaker

Question 11

Syncope
Management
Non-Cardiogenic

Answer 11

Benign causes or low-risk syncope: discharge with GP follow-up
Consider outpatient cardiac workup