Syncope

Background

• 3 Questions

1. Is this true syncope or something else (eg, stroke, seizure, head injury)?
2. If this is true syncope, is there a clear life-threatening cause?
3. If this is true syncope and the cause is not clear, is the pt at high risk?

Risk Factors for Serious Cause

• Exertion preceding the event
• History of cardiac disease in the patient
• Family history of sudden death, deafness, or cardiac disease
• Recurrent episodes
• Recumbent episode
• Prolonged loss of consciousness
• Associated chest pain or palpitations
• Use of medications that can alter cardiac conduction

San Francisco Syncope Rule

• 1.4% of patients who are rule-negative will have a 7-day serious outcome
• 10% of patients meeting the below criteria will have a 7-day serious outcome

Criteria (CHESS Pneumonic)

• CHF History
• Hct < 30%
• ECG Abnormality
• SOB history
• SBP < 90mmHg at triage

Clinical Presentation

Physical Exam

• Evaluate volume status
• Evaluate for head and neck trauma (related to fall from syncopal event)
• Focus cardiac exam on detecting murmurs (AS, MR, tricuspid stenosis)
• Evaluate for signs of heart failure
• Palpate abdomen for pulsating mass (AAA)
• Rectal exam to eval for GI bleeding
• Thorough neurologic exam
• Examine for possible sources of infection

Clinical Features by Cause

• Cardiovascular-mediated syncope
  • Usually occurs without warning (absence of prodrome)
  • H/o structural heart disease
  • Family Hx of sudden cardiac death
  • Syncope during exertion
  • Chest pain or palpitations associated with syncope
  • Abnormal ECG
• Neurally mediated syncope
  • Trigger event (fear/pain, prolonged standing, warm environment)
  • Prodrome of nausea, vomiting, tunnel vision, lightheadedness, diaphoresis, warmth
  • Associated with head movement or pressure on neck
• Orthostatic hypotension-mediated syncope
  • After standing up
  • Change in medications

Differential Diagnosis

• Cardiovascular-mediated syncope:
  • Dysrhythmias:
    • WPW (pre-excitation)
    • Long QT Syndrome
    • Brugada Syndrome
    • 2nd/3rd degree AV block
    • Afib/aflutter
    • Vtach/torsades
    • Sick sinus syndrome
  • Cardiovascular disease:
    • Valvular Disease (AS, MS, tricuspid stenosis)
    • Aortic Dissection
    • Myocardial Infarction
    • CHF
    • PE
    • Pericardial Tamponade
    • Myxoma
    • Pulmonary Hypertension
• Neurally mediated syncope:
  • Vasovagal:
    • Fear, pain, emotion, valsalva, breath-holding spell
  • Situational (associated with):
    • Coughing, micturition, defecation, vomiting
    • Carotid sinus stimulation
• Orthostatic hypotension-mediated syncope:
  • Volume depletion:
    • Dehydration (vomiting, diarrhea)
    • Hemorrhage
    • Sepsis
  • Autonomic Dysreflexia
  • Autonomic failure due to meds
• Other serious causes:
  • SAH
  • TIA
  • Subclavian steal

Management

• Treat cause
  • See also Hypotension

Disposition

Admit

• Abnormal ECG
• CHF
• Suspicion of structural heart disease
  • Ischemic, dysrhythmic, obstructive, valvular
• HCT <30
• Shortness of Breath
• Hypotension (SBP <90)
• Family history of sudden cardiac death
• Advanced age
• Evidence of hemorrhage (occult blood)

Discharge

• None of the above findings (esp if age <45)
• Consider referral for holter or til-table test

External Links

• The NNT (http://thennt.com/risk/syncope-in-the-emergency-department)