Abstract Body (Do not enter title and authors here): Introduction
Coronary-bronchial artery fistula (CBF) is a rare finding with an incidence of 0.08 to 0.61%. Patients may present with chest pain, dyspnea, or hemoptysis. Transcatheter interventions provide definitive treatment for symptomatic patients. Herein, we present a case of recurrent chest pain due to CBF involving the sinoatrial nodal (SAN) artery.

Case
A 75-year-old lady presented with recurrent midsternal chest pain for several years. Her medical history was notable for pulmonary emboli (PE), and antiphospholipid syndrome. Initial investigation showed mildly elevated high sensitivity troponin to 28.9 ng/L. ECG showed normal sinus rhythm without ischemic abnormalities. Prior ischemic work-up including dobutamine stress echocardiogram and invasive coronary angiography was unremarkable. Ventilation perfusion (V/Q) scan showed multiple areas of VQ mismatch. Computed tomography coronary angiography (CTCA) showed a dominant RCA with a 2.5 mm communication between the SAN artery and left bronchial artery. After a heart team discussion, the patient was offered definitive treatment. A 6 Fr FR4 Mach 1 Guide catheter was used for selective right coronary angiography. A steerable microcatheter floppy 0.014”x 300 cm wire was used to engage the fistula originating from SAN artery (Figure 1). A micro vascular plug was successfully deployed over the wire without endangering sinus nodal supply. Post-intervention there was decrease in flow from the SAN to the bronchial artery (Figure 2). At one month follow up the patient was chest pain free.

Discussion
Patients with pulmonary vascular disease might be predisposed to CBF, as chronic pulmonary ischemia might augment collateral blood flow. As a result, coronary steal phenomenon may lead to atypical angina. CTCA is a helpful screening tool, while transcatheter intervention may benefit symptomatic individuals.

Conclusion
CBF should be considered in patients with history of PE and recurrent chest pain of unclear etiology.