III. History: Timing of Syncope
- Most important to distinguish timing of syncopal event
- Syncope during Exercise (Exertional Syncope)
-
Syncope following Exercise (Exercise collapse, Heat Syncope)
- Typically benign cause
- Transient Orthostatic Hypotension
- Often occurs with Exercise in hot environments, with vasodilation and increased sweating
- Worse with prolonged standing that results in lower extremity venous pooling
- Vasovagal episode related to sudden decrease in venous return
- Secondary to volume depletion, post-exercise Bradycardia and peripheral vasodilation
IV. Symptoms
- Light Headedness, Orthostasis or Dizziness immediately following Exercise
- Transient loss of consciousness
V. Exam
- See Syncope
- Vital Signs (Identify Hypotension, Tachycardia)
- Thorough examination (especially cardiovascular)
VI. Causes: Exertional Syncope (Syncope during Exercise)
- See Arrhythmias in Athletes
- See Sudden Death in Athletes
- Cardiovascular - Arrhythmia
- Cardiovascular - Valvular disease
- Aortic Stenosis
- Mitral Valve Prolapse
- Ebstein's Anomaly of the Tricuspid Valve
- Cardiovascular - structural
- Miscellaneous causes in athletes
VII. Precautions: Red Flags suggestive of cardiogenic Syncope
VIII. Labs
- Bedside Glucose
- Basic chemistry panel (Serum Electrolytes)
- Complete Blood Count
- Creatinine Kinase (CPK)
IX. Evaluation
- See Syncope
- See Heat Illness
- Electrocardiogram
-
Echocardiogram
- If indicated
X. Management
- Immediate management
- See Heat Illness
- Position patient supine with legs elevated
- Encourage oral hydration
- Initiate external cooling if concern for Heat Exhaustion or Heat Stroke
- Anticipate symptom resolution in 15-20 minutes
- Follow-up
- Avoid Exercise and avoid return to sport until evaluation is complete
- Evaluate for cardiogenic Syncope if red flags as above
- Cardiology Consultation
XI. References
- Spangler and Baird in Herbert (2014) EM:Rap 14(2): 7-8
- Colivicchi (2004) Eur Heart J 25(19): 1749-53 [PubMed]