1. UCI Internal Medicine Core Curriculum – Mini Lecture Asad Qasim – PGY3
Syncope
UCI Internal Medicine Core Curriculum – Mini Lecture
Asad Qasim – PGY3

2. Learning Objectives Understand the Definition of Syncope
Know the Basic Etiologies of Syncope
Know how to Work-up High vs Low Risk Syncope

3. What is Syncope?
Syncope is the abrupt and transient loss of consciousness associated with absence of postural tone, followed by complete and usually rapid spontaneous recovery. The underlying mechanism is global hypoperfusion of both the cerebral cortices or focal hypoperfusion of the reticular activating system.

4. What is Syncope?
It is important to distinguish Syncope from other causes of T-LOC (Transient Loss of Consciousness)
Pre-Syncope: lightheadedness without LOC
Drop Attack: loss of posture without LOC
Coma: LOC without spontaneous recovery
Seizure: Tonic-Clonic Movements that start WITH LOC (vs hypoxic myoclonus which can occur with syncope), post- ictal recovery period
Hypoglycemia
Hypoxia
TIA
Cardiac Arrest
Go through this quickly.
Important point to make is that most of these entities can be differentiated from true syncope based on history from the patient

5. Etiologies of Syncope Neurocardiogenic / Vasovagal Cardiovascular
Most Common
Pain/Noxious Stimuli
Situational (micturation, cough, defecation)
Carotid Sinus Hypersensitivity (CSH)
Fear
Prolonged standing / heat exposure
Cardiovascular
Most Dangerous
Arrhythmia – Tachy or Brady
Valve Stenosis (outflow obstruction)
HOCM (outflow obstruction)
Orthostatic Hypotension
“ D A A D “
Drugs: BP meds, Diuretics, TCAs
Autonomic Insufficiency (Parkinsons, Shy-Dragger, DM, Adrenal Insufficiency)
Alcohol
Dehydration
Neuro / Functional / Psychiatric - <5%
Psuedosyncope
TIA or Vertibro-basilar Insufficiency
Most Common – Reflex Syncope (neurocardiogenic/vasovagal)
Most Dangerous – Cardiovascular
Neurological causes of T-LOC are technically not syncope, but may be on the differential if the presentation is unclear

6. Work-up and Risk Stratification
The syncope work-up should determine who is at HIGH RISK for a dangerous short-term cardiac event.
All patient should get basic Work-up Including
History/Physical including Orthostatics
Medication Review
ECG.
If age >40, consider Carotid Sinus Massage to assess for Carotid Sinus Hypersensitivity
CONTRAINDICATED if carotid bruit present or recent TIA/Stroke
+ Test = bradycardia, hypotension, transient pause/asystole, or prodrome symptoms
All patients should then be Risk Stratified
Adapted from AHA/ACCF Scientific Statement on the Evaluation of Syncope. (Circulation.2006;113: )
Adapted from AHA/ACCF Scientific Statement on the Evaluation of Syncope. (Circulation.2006;113: )

7. Work-up and Risk Stratification
High Risk: These patients are at high risk for short term cardiac mortality and need appropriate cardiac work-up as an INPATIENT
Evidence of significant heart disease (such as heart failure, low left ventricular ejection fraction, structural abnormality, or previous myocardial infarction).
Clinical (eg palpitations) or ECG features suggesting arrhythmia
Comorbidities such as severe anemia or electrolyte disturbance.
High Risk Work-Up
Echo, Stress test, and/or Ischemic Evaluation
Check for recent Echo and/or TMST before ordering a new one!
Consider Posterior Circulation imaging of the brain if suspect Neurological “syncope”
Carotid Ultrasound has POOR utility in the workup of Syncope and should not be ordered routinely.
Identify patients at high risk for short term events, these patient's should be hospitalized and monitored on telemetry while you continue your cardiac workup
Low risk patients do not need emergent hospitalization or work-up. (next slide)

8. Work-up and Risk Stratification
Low Risk: Patient’s with no High risk characteristics and/or with highly suspected Vasovagal or Neurocardiogenic Etiology
Single Episode: No further workup indicated
Multiple Episodes: Can workup as outpatient
Patient having FREQUENT Episodes: Holter Monitor or Event Monitor
Patient having INFREQUENT Episodes: Implantable Loop Recorder
These patients DO NOT need “ACS Rule Out” or Imaging (including Head CT or Carotid Ultrasound)
Tilt Table Testing is optional for difficult to diagnose orthostasis but is falling out of favor due to poor reproducibility and low Sen/Spec
EP Studies are also an option for rare or difficult to diagnose cardiac syndromes

9. Imaging in the Workup of Syncope
So When do I get Brain Imaging?
Neurological Causes of true Syncope are RARE
Bilateral Carotid or Basilar Artery Disease
Non-convulsive Seizure
Head CT is indicated ONLY if the patient has or experienced focal neurological deficits or they experienced head trauma from the event.
Carotid Ultrasound has LOW utility and should NOT be ordered routinely.
Posterior Circulation evaluation with CTA/MRA or Ultrasound is useful only if Vertibro-basilar insufficiency is suspected
Typically present with Dizziness, gait instability, blurry vision, nystagmus, or frank Coma.
CNS imaging is of low utility in the work-up of syncope and should be used only the situations noted above. This is also the recommendations of the ACC/AHA Scientific Statement on the Evaluation of Syncope. (Circulation.2006;113: )
Next slides are a few cases to practice

10. “Hey its Triage, have this syncope admit”
71y/o M presents after he passed out while walking up the stairs. He felt slightly lightheaded just prior to the event. Wife saw him fall but was able to quickly arouse him. He had no incontinence or tongue biting. Similar event occurred 2 weeks prior while he was doing yard-work for which he did not seek medical care. He has a long history of DM, and hypertension for which he takes Glipizide, Amlodipine, Lisinopril, and HCTZ. He does not drink. Vitals, orthostatics, and blood sugar are unremarkable. ECG shows left axis deviation and LVH. Exam shows 1+ bilateral edema and 4/6 ejection murmur radiating to the carotids.
What risk category is this patient and how would you proceed with workup?
High risk patient with recurrent episodes of syncope and H/P suspicious for Aortic Stenosis.
Needs admission, telemetry, Echo

11. “Hey its Triage, have this syncope admit”
H/P, Orthostatics, ECG, Meds
ECG shows evidence of structural heart disease and exam shows murmur. No orthostasis or suspicious history of vasovagal syncope. Patient has had multiple episodes.
Based on initial workup, patient is High Risk
Needs Admission and Cardiac Work-up including Echocardiogram and Stress Test
Dx: Aortic Stenosis
Click again for Diagnosis

12. “Last admit of the day!”
35y/o healthy M presents with an episode of syncope while standing. He did not experience any prodrome symptoms. This has never happened before. He has no medical history and uses no medications, drugs, or EtoH. Physical exam and ECG are normal. No orthostasis. Carotid massage is negative. Routine labs are unremarkable.
What risk category is this patient and how would you proceed with workup?
Low Risk patient with single episode of syncope with negative initial (step 1- H&P, orthostatics, EKG) evaluation - NO FURTHER WORKUP

13. Last admit of the day!
H/P, Orthostatics, ECG, Meds - normal with no obvious cause of syncope
Patient is Low Risk and has had only a Single Episode of syncope
No Further Work-up Indicated
What if the same patient presented with syncope while working out at the gym and physical exam showed a grade III systolic murmur that increased with Valsalva?
Patient is now High Risk given possible structural heart disease and exertional syncope
Admit to telemetry for cardiac work-up including Echocardiogram to evaluate for Hypertrophic Cardiomyopathy.
Click again, for case variant on bottom half of this slide.
- Same patient with exercise induced syncope and murmur on exam suggestive of HOCM. Now a High Risk patient with possible structural heart disease. Needs admission, tele, and Echo.

14. Key Points Key Differential Dx Work-up and Risk Stratification
Vasovagal/Neurocardiogenic - most common
Cardiac – HIGH RISK PATIENTS, most dangerous
Orthostatic – “D A A D”
Other - Neurologic, Functional, Psych
Work-up and Risk Stratification
H/P, Orthostatics, Meds, ECG, +/- Carotid Massage
Risk Stratify
High Risk - Admit w/ cardiac work-up
Low Risk - Outpatient workup based on frequency of episodes
Brain Imaging ONLY if focal Neuro Deficits or Head trauma

15. References
AHA/ACCF Scientific Statement on the Evaluation of Syncope. (Circulation.2006;113: )
ESC Guidlines for the Diagnosis and Management of Syncope. (European Heart Journal ; )
UptoDate
Management of Syncope in the Emergency Department
Etiology and Pathogenesis of Syncope
Diagnosis and Management of Syncope in Adults
Cases Adapted from NMS Medicine Casebook. Tilak Shah 2009