**Introduction/Hypothesis:**
Coronary artery fistula (CAF) is a rare and abnormal connection between coronary arteries and cardiac chambers. Most CAFs are congenital but others can be acquired through iatrogenic or traumatic injuries and systemic inflammatory conditions. Although anatomy of CAFs vary, common origins include the right and left coronary arteries with connections to the right ventricle or right atrium.

**Methods**
A 37-year-old female presented with exertional dyspnea, heart murmur, and arm paresthesia during pregnancy and was diagnosed with a left circumflex (LCX) to left atrium (LA) fistula on cardiac gated computed tomography angiogram (CTA). This gravida 2 para 2 patient was referred to our center after an insidious onset of exertional dyspnea during 2 pregnancies, the second of which terminated in cesarean section.

**Results**
Transthoracic echocardiography revealed the LCX to LA CAF with turbulent flow into left atrium and a moderately enlarged left atrium. Cardiac CTA confirmed the tortuous and aneurysmal CAF revealing aneurysmal dilations of the involved coronaries to up to 26 mm and several calcified and noncalcified atherosclerotic plaques within the aneurysmal LCX. The fistulous connection was closest to the left atrial appendage. Direct cardiac catheterization of the LCX redemonstrated the LCX to LA CAF with contrast opacification of the LA prior to treatment with coil embolization. The patient tolerated the procedure well without complications

**Conclusion**
Overall, CAFs are a rare phenomenon present in less than 0.002% of the general population. They are rare among cardiac anomalies (0.2%-0.4%) and even coronary anomalies (14%). A few case reports of pregnancy associated CAFs have been described in the literature. Treatment depends on the size and symptoms. Small and asymptomatic CAFs warrant only observation. Small, symptomatic CAFs can be managed with antiplatelet therapy and antibiotics to prevent endocarditis. Large fistulas are best suited for surgical ligation.



Postpartum left circumflex to left atrial fistula

This course will explore basic and cutting-edge imaging techniques to improve patient care and hone individual skills in performance and interpretation of echocardiography, nuclear cardiology, cardiac computed tomography, and cardiovascular magnetic resonance imaging. Days will reinforce how cardiovascular imaging may improve comprehension in ischemic heart disease, structural heart disease, cardiomyopathies, and heart failure. Experts will utilize novel techniques to reinforce key topics including taped interventional cases and a strong emphasis on case presentations.