Exercise Induced Syncope

Aka: Exercise Induced Syncope, Syncope in Athletes, Exertional Syncope, Effort Syncope, Exercise-Associated Collapse, Heat Syncope

1. See Also
   1. Syncope
   2. Arrhythmias in Athletes
   3. Sudden Death in Athletes
   4. Heat Illness
2. Definitions
   1. Exercise Related Syncope
      1. Loss of consciousness associated with Exercise
3. History: Timing of Syncope
   1. Most important to distinguish timing of syncopal event
      1. Syncope during Exercise is ominious compared with the relatively benign post-ExerciseSyncope
   2. Syncope during Exercise (Exertional Syncope)
      1. True Syncope during Exercise is rare and should be thoroughly evaluated
      2. High risk for serious cause
      3. Consider equivalent of transient sudden death
   3. Syncope following Exercise (Exercise collapse, Heat Syncope)
      1. Typically benign cause
      2. Transient Orthostatic Hypotension
         1. Often occurs with Exercise in hot environments, with vasodilation and increased sweating
         2. Worse with prolonged standing that results in lower extremity venous pooling
         3. Vasovagal episode related to sudden decrease in venous return
         4. Secondary to volume depletion, post-exercise Bradycardia and peripheral vasodilation
4. Symptoms
   1. Light headedness, Orthostasis or Dizziness immediately following Exercise
   2. Transient loss of consciousness
5. Exam
   1. See Syncope
   2. Vital Signs (Identify Hypotension, Tachycardia)
   3. Thorough examination (especially cardiovascular)
6. Causes: Exertional Syncope (Syncope during Exercise)
   1. See Arrhythmias in Athletes
   2. See Sudden Death in Athletes
   3. Cardiovascular - Arrhythmia
      1. Arrhythmogenic Right Ventricular Dysplasia (ARVD)
      2. Long QT Syndrome
      3. Brugada Syndrome
      4. Wolff-Parkinson-White Syndrome (WPW Syndrome)
   4. Cardiovascular - Valvular disease
      1. Aortic Stenosis
      2. Mitral Valve Prolapse
      3. Ebstein's Anomaly of the Tricuspid Valve
   5. Cardiovascular - structural
      1. Hypertrophic Cardiomyopathy
      2. Coronary Artery Disease or Coronary Artery Abnormalities
      3. Myocarditis
      4. Marfan's Syndrome
   6. Miscellaneous causes in athletes
      1. Heat Stroke
      2. Hypoglycemia
      3. Hyponatremia
      4. Anaphylaxis
7. Precautions: Red Flags suggestive of cardiogenic Syncope
   1. Syncope during Exercise (see above) in contrast to the typically benign Syncope that follows Exercise
   2. Cardiovascular Risk Factors
   3. Advanced age
   4. Cardiac symptoms follow Syncope
   5. Delayed recovery
8. Labs
   1. Bedside Glucose
   2. Basic chemistry panel (Serum Electrolytes)
   3. Complete Blood Count
   4. Creatinine Kinase (CPK)
9. Evaluation
   1. See Syncope
   2. See Heat Illness
   3. Electrocardiogram
      1. See Electrocardiogram in Syncope
   4. Echocardiogram
      1. If indicated
10. Management
    1. Immediate management
       1. See Heat Illness
       2. Position patient supine with legs elevated
       3. Encourage oral hydration
       4. Initiate external cooling if concern for Heat Exhaustion or Heat Stroke
       5. Anticipate symptom resolution in 15-20 minutes
    2. Follow-up
       1. Avoid Exercise and avoid return to sport until evaluation is complete
       2. Evaluate for cardiogenic Syncope if red flags as above
       3. Cardiology Consultation
11. References
    1. Spangler and Baird in Herbert (2014) EM:Rap 14(2): 7-8
    2. Colivicchi (2004) Eur Heart J 25(19): 1749-53 [PubMed]