Evaluation of Syncope

1. Evaluation
of Syncope
Dr. Charles Nelson
November 14, 2014

2. Syncope: A Symptom, not a Diagnosis
• Self-limited loss of consciousness and postural tone
• Relatively rapid onset
• Variable warning symptoms
• Spontaneous, complete, and usually prompt recovery
without medical or surgical intervention
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3. Syncope Mimics
• Acute intoxication (e.g., alcohol)
• Seizures
• Sleep disorders
• Somatization disorder (psychogenic pseudo-syncope)
• Trauma/concussion
• Hypoglycemia
• Hyperventilation
Brignole M, et al. Europace, 2004;6:467-537.

4. Syncope: Epidemiological Data
• 40% population, presumed syncope at least once1
• 1-6% of hospital admissions2
• Approx 1% of ED visits per year3,4
• 10% of falls by elderly are believed due to syncope5
• Injuries:
• 6% major morbidity (e.g., fractures, MVA)1
• Minor injury in 29%1
1Kenny RA, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.
2Kapoor W. Medicine. 1990;69:160-175.
3Brignole M, et al. Europace. 2003;5:293-298.
4 Blanc J-J, et al. Eur Heart J. 2002;23:815-820.
5Campbell A, et al. Age and Ageing. 1981;10:264-270.

5. Syncope & Collapse: Emergency Department
US Data 2006
• Emergency Department visits
• Primary Diagnosis ~1.13 million
• Among all listed diagnoses >1.35 million
• Hospital admission rate, ~36%

6. Impact of Syncope in USA: Annual Expenditures
• Estimated hospital costs > $5400/hospitalization
• Treating ‘falls’ in older adults1 >$7 billion
1. Benjamin C. Sun, MD, MPP, Jennifer A. Emond, MS, and Carlos A. Camargo, Jr., MD, DrPH “Direct medical
costs of syncope-related hospitalizations in the USA Am J Cardiol 2005;95:668-671
2 Kenny RA, Kapoor WN. In: Benditt D, et al. eds. The Evaluation and Treatment of Syncope. Futura;2003:23-27.

7. Syncope & Collapse: Estimated Hospitalization
Costs
Conservative estimates of annual cost:
• Syncope / Collapse - $2.4 billion
• Asthma - $2.8 billion
• HIV - $2.2 billion
• COPD - $1.9 billion

8. Causes of True Syncope
Orthostatic Cardiac
Arrhythmia
Structural
Cardio-
Pulmonary
1•
VVS
• CSS
• Situational
Cough
Post-micturition
2•
Drug-Induced
• ANS Failure
Primary
Secondary
3•
Bradycardia
Sinus
pause/arrest
AV block
•Tachycardia
VT
SVT
• LongQT Synd
4
• Aortic
Stenosis
• HCM
• Pulmonary
Hypertension
• Aortic
Dissection
Neurally-
Mediated
Reflex
6600%% 1155%% 1100%% 55%%
Unexplained Causes = Approximately 10%

9. Impact of Syncope on Mortality Risk
• Vasovagal Syncope has low
mortality risk
– But recurrences are a concern
• Syncope of presumed cardiac
cause is associated with high
mortality risk
– Most evidence suggests that risk is
similar to that of patients without
syncope but with similar severity of
heart disease
Soteriades ES, Evans JC, Larson MG, et al. Incidence and prognosis of syncope. N
Engl J Med. 2002;347(12):878-885. [Framingham Study Population]

10. Diagnostic Goal
Establish cause of syncope with sufficient certainty to:
• Assess prognosis confidently
• Initiate effective preventive treatment

11. Neurological Tests:
Tests:
Rarely Rarely Diagnostic Diagnostic for Syncope
for Syncope
• EEG, Head CT, Head MRI
carotid dopplers
• May help diagnose seizure
• Reasonable if syncope has
resulted in closed head
injury or if focal neuro
findings
Brignole M, et al. Europace. 2004;6:467-537.

12. Clinical Features Suggesting Cause of Syncope:
ESC Syncope Task Force 2004
• Neurally-mediated Reflex Syncope
– Absence of cardiac disease (except CSS)
– Long history of recurrences
– Associated with emotional event, pain, prolonged upright posture, hot
environment, head rotation
– After strenuous exertion
• Orthostatic Syncope
– Associated with change to upright posture, prolonged standing, dehydration
– Recent addition of diuretic, vasodilator, etc
– History of neuropathy, diabetes, alcohol abuse
CSS=carotid sinus syndrome

13. Neurally-Mediated Reflex Syncope (NMS)
• Vasovagal Syncope (VVS)
• Carotid Sinus Syndrome (CSS)
• Situational Syncope
– post-micturition
– cough
– swallow
– defecation
– blood drawing
– etc.

14. NMS:Clinical Pathophysiology
• Neurally-mediated physiologic reflex mechanism with two
components:
– Cardioinhibitory ( HR )
– Vasodepressor ( BP )
• Both components are usually present:
– Vasodepressor may be masked in the presence of severe
bradycardia
– Pace or pre-treat with atropine in order to observe
Vasodepressor component

15. Orthostatic Intolerance Syndromes
Orthostatic
Syncope
PPOOTTSS
Vasovagal
Orthostatic Syncope
Intolerance

16. Orthostatic Hypotension- Etiology
• Drug-induced (very common)
– Diuretics, Vasodilators
• Primary autonomic failure
– Multiple system atrophy, Parkinsonism
• Secondary autonomic failure
– Diabetes, Alcohol, Amyloid

17. Clinical/ECG Features For Cardiac Syncope
• Presence of severe structural heart disease
• Family history of sudden death
• Syncope during exertion or while supine
• Palpitations at time of syncope
• Heart failure / LV Dysfunction
• ECG / Monitor findings of:
– Baseline Wide QRS Complex
– Mobitz 1 second degree AVB
– Sinus bradycardia <50 bpm
– Documented Non Sustained or Sustained VT
– Preexcitation, Long QT, t wave inversion
– Bifasicular block
Adapted from ESC Syncope Guidelines– Update 2004

18. Syncope Due to Structural CV Disease
• Acute MI / Ischemia
• Acquired coronary artery disease
– Congenital coronary artery anomalies
• Hypertrophic Cardiomyopathy (HCM)
• Arrhythmogenic RV Dysplasia (ARVD)
• Acute aortic dissection
• Acute pulmonary embolus/pulmonary hypertension
• Valvular abnormalities
– Aortic stenosis
– Mitral stenosis
• Atrial myxoma
• Intra-cardiac thrombus (ball-valve thrombus)

19. Syncope Due to Cardiac Arrhythmias
• Bradyarrhythmias
– Sinus arrest, exit block
– High grade or acute complete AV block
• Tachyarrhythmias
– Atrial fibrillation/flutter with rapid ventricular rate
(e.g., WPW syndrome)
– Paroxysmal SVT or VT
– Torsades de pointes (e.g., long QT syndrome)

20. The Initial Evaluation: 4 Key Questions
• Did the patient suffer ‘true’ Transient Loss of
Consciousness (TLOC)?
• Was TLOC due to syncope or mimic?
• Is heart disease present?
• Does the medical history (including observations by
witnesses) suggest a specific diagnosis?

21. Hospital Admission for Diagnosis or Treatment
Occasionally may need to be admitted
•No heart disease but sudden onset of palpitations shortly before
syncope or high suspicion of cardiac syncope
•Other sig condition associated with though not cause of syncope
•Syncope in supine position,
•Frequent recurrent episodes, injuries
ESC Syncope Task Force 2004

22. Diagnostic Testing
• Exertional syncope or exertional symptoms: stress test
• Signs or symptoms CHF, murmurs: echo
• Palpitations or tachycardia preceeding event: holter or
event
• Abnormal ekg (heart block, bifasicular block): holter or
ILR
• Suspected (but uncertain) NMS: tilt test
• Pts that are orthostatic do not need tilt test

23. When do not need refer to specialist
• No need to refer when cause for syncope is certain,
and no evidence of significant heart disease.
• No need to refer if diagnosis is uncertain, but
episode did not result in significant injury and is not
recurrent.

24. When to refer to specialist
• When initial evaluation or testing indicates underlying significant
heart disease (abnormal ekg or echo)
• When need tilt testing to confirm cause of syncope
• When syncope is recurrent in spite of treatment for suspected
cause
• When cause is uncertain and syncope is recurrent
• Anytime you have a question that you cant answer or are not
sure how to proceed in evaluating the patient.

25. Feedback and Questions

26. Treatment Strategies for Orthostatic Intolerance
• Patient education, injury avoidance
• Hydration
– fluids, salt, diet
– minimize caffeine/alcohol
• Sleeping with head of bed elevated
• Tilt Training, leg crossing, arm tensing
• Support hose, abdominal binders
• Drug therapies
– fludrocortisone, midodrine, erythropoietin