Syncope
Revision as of 20:15, 5 May 2014 by Mceledon83 (talk | contribs)
Background
- 3 Questions
- Is this true syncope or something else (eg, stroke, seizure, head injury)?
- If this is true syncope, is there a clear life-threatening cause?
- If this is true syncope and the cause is not clear, is the pt at high risk?
- Etiology is divided into 3 major categories
- Clinical features in each category suggesting diagnosis of syncope:
- Cardiovascular-mediated syncope
- Usually occurs without warning
- H/o structural heart disease
- Family Hx of sudden cardiac death
- Syncope during exertion
- 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
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)[1]
- CHF History
- Hct < 30%
- ECG Abnormality
- SOB history
- SBP < 90mmHg at triage
DDX
- 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 HTN
- Dysrhythmias:
- Neurally mediated syncope:
- Vasovagal:
- Fear, pain, emotion, valsalva, breath-holding spell
- Situational (associated with):
- Coughing, micturition, defecation, vomiting
- Carotid sinus stimulation
- Vasovagal:
- Orthostatic hypotension-mediated syncope:
- Volume depletion:
- Dehydration (vomiting, diarrhea)
- Hemorrhage
- Sepsis
- Autonomic dysreflexia
- Autonomic failure due to meds
- Volume depletion:
- Other serious causes:
- SAH
- TIA
- Subclavian steal
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
Work-Up
- Overall yield of testing is low
- ECG
- Normal ECG has high NPV
- Perform on every pt, unless trigger clearly identified (i.e. following blood draw) and no risk factors
- R/o: Ischemia, heart block, WPW, long QT, Brugada
- ECG findings associated with adverse cardiac outcome in 30 days:
- LBBB, 2nd degree Mobitz II, 3rd degree AV block, RBBB w/LAFP or LPFB
- Urine pregnancy
- Consider based on history/symptoms:
- CXR
- Obtain if symptomatic (i.e. r/o dissection)
- Hemoglobin
- Chemistry
- Orthostatics (symptomatic)
- Troponin
- Not recommended to r/o AMI in patients with isolated syncope
- Elevated troponin predicts adverse cardiac outcome in syncope
- May be useful for risk stratification
- Guaiac
Treat
- Treat cause
- See also Hypotension
Disposition
- Admit
- Abnormal ECG
- CHF
- Suspicion of structural heart disease
- HCT <30
- Shortness of Breath
- SBP <90
- Family history of sudden cardiac death
- Advanced age
- Discharge
- None of the above findings (esp if age <45)
- Consider referral for holter or til-table test
Source
- Tintinalli
- UpToDate
- ACEP Clinical Policy 2007
- The NNT (http://thennt.com/risk/syncope-in-the-emergency-department)
- ↑ Quinn J, McDermott D, Stiell I, Kohn M, Wells G. Prospective validation of the San Francisco Syncope Rule to predict patients with serious outcomes. Ann Emerg Med. 2006 May;47(5):448-54. PubMed PMID: 16631985.