HISTORY: A 15-year-old female HS lacrosse player presented for episodes of chest pain and palpitations, initially at rest for minutes and then became exertional with SOB. She denied nausea, HA, and syncope. Family history was negative for congenital heart disease and sudden cardiac death, but her mother had atrial fibrillation and MGF died before age 60 from an MI. PHYSICAL EXAMINATION: T 97.7°F, HR 56, BP 116/68, RR 20, SpO2 98% RA, BMI 20.7 Well appearing with clear breath sounds. Cardiac exam: regular rhythm, normal S1 and S2, no S3 or S4, and a 2/6 low frequency systolic murmur best heard at the left upper sternal border. 2+ pulses. No peripheral edema, cyanosis, or hepatomegaly. DIFFERENTIAL DIAGNOSIS: 1. arrhythmia - SVT, WPW, aflutter, afib, PACs 2. pulmonary valve stenosis, tricuspid valve regurgitation 3. cardiomyopathy—hypertrophic cardiomyopathy, ARVD 4. ASD 5. anemia 6. hyperthyroidism TEST AND RESULTS: -ECG- sinus bradycardia, no chamber enlargements or pre-excitation, normal QTc -28 day event monitor- two episodes of chest pain and rapid heart beat correlate with nsr and sinus tachycardia -Transthoracic echocardiogram- normal cardiac segmentation, valvular function, biventricular size, and systolic function. No effusion. There is a small coronary cameral fistula entering the main pulmonary artery. -Exercise stress with 2D echocardiogram performed showed normal EF with no wall motion abnormalities, ischemia, or arrhythmias FINAL WORKING DIAGNOSIS: Coronary-cameral fistula TREATMENT AND OUTCOMES: 1. The patient was cleared to play after symptoms spontaneously resolved and serial echocardiograms over a 5 year period demonstrated a stable coronary-cameral fistula. 2. Cardiology consultants recommended a rest/stress MRI to further determine the anatomical nature of the fistula given the symptom history. However, they believe that the fistula was an incidental finding and likely not the cause of her symptomatology. 3. Coronary-cameral fistula is a rare cause of congenital cardiac anomalies. Although most are small and asymptomatic, larger ones may cause MI or CHF, thus requiring intervention. 4. There are no published reports of this condition in athletes, highlighting provocative issues surrounding risks of incidental findings of unknown significance and return to play considerations.