What is the emergent approach to managing a patient with syncope?

Emergent Approach to Syncope

Immediate Life-Threatening Exclusions First

The primary goal in the emergency setting is to rapidly identify and treat life-threatening cardiac causes, which carry 18-33% one-year mortality compared to 3-4% for non-cardiac causes. 1

High-Risk Features Requiring Immediate Hospitalization

• Syncope during exertion or while supine suggests cardiac etiology rather than benign vasovagal syncope 2, 1
• Absence of prodrome (no warning symptoms like nausea, diaphoresis, lightheadedness) is concerning for cardiac causes 1
• Chest pain suggesting acute coronary syndrome 1
• Known structural heart disease including valvular disease, cardiomyopathy, or heart failure 2, 1
• Family history of sudden cardiac death or inherited cardiac conditions 2, 1
• Abnormal ECG findings suggesting arrhythmia 2
• Age >60 years with concerning features 2

Mandatory Initial Assessment

Every syncope patient requires three immediate evaluations: 2, 3

1. 12-lead ECG - This is essential and can identify lethal causes immediately 2, 1. Look for:

   • Bundle branch block or intraventricular conduction delay (associated with increased mortality) 1
   • Left ventricular hypertrophy 1
   • Atrial fibrillation 1
   • Signs of ischemia or infarction 1

2. Detailed history focusing on:

   • Circumstances: exertional, supine position, situational triggers 2, 1
   • Prodromal symptoms: presence or absence 2, 1
   • Recovery time: slow recovery is alarming 4
   • Number of episodes: single vs. recurrent 2
   • Cardiac history and medications 2

3. Physical examination with orthostatic vital signs 2

Critical Cardiac Causes to Rule Out

• Ventricular arrhythmias (VT, torsades de pointes) particularly with structural heart disease 1
• High-grade AV block or complete heart block 1
• Acute myocardial infarction or ischemia 1
• Severe aortic stenosis (average survival only 2 years without valve replacement when presenting with syncope) 1
• Hypertrophic cardiomyopathy especially with exertional syncope, young age, or family history 1
• Acute aortic dissection 1
• Cardiac tamponade 1
• Pacemaker/ICD malfunction in device-dependent patients 1

Critical Non-Cardiac Causes

• Pulmonary embolism causing acute right heart failure 1
• Subarachnoid hemorrhage (may present as syncope without typical headache) 1
• Significant hemorrhage (GI bleeding, ruptured ectopic pregnancy, ruptured AAA) 1

Risk Stratification and Disposition

Admit to Hospital

Patients with any of the following require admission: 2

• Identified serious medical conditions 2
• High-risk features listed above 2
• Suspected cardiac syncope with concerning features 2
• Abnormal ECG suggesting arrhythmia 2
• History of heart failure or structural heart disease 2

Admitted patients require continuous ECG monitoring 2

Intermediate Risk - Consider ED Observation or Rapid Outpatient Follow-up

• Recurrent episodes without clear diagnosis 2
• Age >60 years without clear vasovagal features 2
• These patients may benefit from structured ED observation protocols 2

Safe for Discharge

Low-risk patients suitable for outpatient management include: 2

• Presumptive reflex-mediated (vasovagal) syncope with clear triggers 4, 2
• Young age without cardiac disease 4
• Normal ECG and cardiac examination 4
• Single episode with typical prodrome (nausea, diaphoresis, warmth, pallor) 4
• Clear situational triggers (prolonged standing, emotional stress, pain, medical procedures) 4

Targeted Diagnostic Testing

Avoid routine comprehensive testing - use targeted approach based on clinical suspicion: 2

When to Order Additional Tests

• Cardiac imaging (echocardiography): Only when structural heart disease is suspected 2
• Blood tests: Only based on clinical assessment from history, physical exam, and ECG 2
• BNP and high-sensitivity troponin: Uncertain utility even when cardiac cause is suspected 2
• Avoid: Routine neuroimaging, EEG, or Holter monitors without specific clinical indication 5

Cardiac Monitoring Selection

Choice depends on frequency and nature of events: 2

• Continuous inpatient monitoring: For hospitalized patients with suspected cardiac etiology 2
• External monitoring options: Holter monitor, external loop recorder, patch recorder, or mobile cardiac outpatient telemetry for selected ambulatory patients with suspected arrhythmic syncope 2

Common Pitfalls to Avoid

• Do not order routine neuroimaging - brain CT/MRI has low diagnostic yield without head trauma or neurologic signs 5
• Do not order routine EEG - only indicated when loss of consciousness cannot be attributed to syncope 4
• Do not use short-term Holter monitors indiscriminately - wasteful without specific arrhythmia suspicion 5
• Do not miss supine or exertional syncope - these are red flags for cardiac causes 2, 1
• Do not discharge patients >60 with heart disease without thorough evaluation 2

Special Consideration for Vasovagal Syncope

If vasovagal syncope is diagnosed (most common cause), management includes: 4

• Patient education on diagnosis and benign prognosis (Class I recommendation) 4
• Instruction to assume supine position when prodrome occurs 4
• Physical counter-pressure maneuvers (leg crossing, limb/abdominal contraction, squatting) for those with sufficient prodrome 4
• Avoidance of triggers (hot crowded environments, volume depletion, prolonged standing) 4