Episodes Of Near-syncope In A Runner

Abstract

HISTORY: A 14-year-old female cross-country & track athlete presents with complaints of near syncope towards the end of exercise. Her symptoms do not occur during training only during competitive events in particular when attempting to catch an opponent near the end of a race. She is also a swimmer and has never experienced symptoms with competitive swimming. These episodes have been accompanied by lightheadedness and dizziness and she would “stumble” across the finish line. They have not resulted in bodily injury and she recovers quickly. She has no other past medical history or medications. The family history is noncontributory. PHYSICAL EXAMINATION: Height 5’3”. Weight 98 pounds. BMI 17.4 Blood Pressure 101/56; heart rate 97 bpm Well-developed young female who appears mildly anxious Normal lung auscultation Cardiovascular exam with regular rate and rhythm; no murmurs/gallops/rubs DIFFERENTIAL DIAGNOSIS: 1. Primary cardiac arrhythmia 2. Cardiovascular structural abnormality 3. Vasovagal response 4. Postural orthostatic tachycardia syndrome 5. Anxiety TESTS AND RESULTS: ECG: Normal ECG with sinus rhythm at 83bpm. Echocardiogram: All chambers normal size and function with no valvular abnormalities. Baseline Spirometry: Normal Cardiopulmonary Stress Test with reproduction of symptoms on the treadmill: Peak VO2 45.3 mL/Kg/min (100% predicted) Peak O2 pulse 9 mL/beat (97% predicted) Max HR 212 bpm (103% predicted) Stress ECG: sinus rhythm throughout without ischemic changes Immediate recovery BP 124/60 (peak BP not obtained due to symptoms) Peak respiratory rate 77 (53 at AT) Tidal volume at peak 899 mL/breath (resting 612 mL/breath; AT 821 mL/breath) Breathing reserve at peak 32% VE/VCO2 at AT 26 Vt/FVC at peak 29% (27% at AT) FINAL WORKING DIAGNOSIS: Dysfunctional breathing with patterned disorder breathing TREATMENT/OUTCOMES: 1. Reassurance of no primary cardiovascular abnormality 2. Lifestyle modification including liberalizing salt and fluid intake 3. Encouragement to work on breathing mechanics with her coaches and/or referral to speech pathology