Coronary artery fistula and bronchiectasis: case report and literature review.

Coronary artery fistula (CAF) is characterized by abnormal communication between the main coronary artery and the cardiac chambers, pulmonary arteries, vena cava, and systemic arteries and veins, and is a rare cardiac malformation. Bronchiectasis involves remodeling and persistent dilatation of the bronchial airways. It can either be localized to one lung segment or diffused throughout the whole lung. The incidence of bronchiectasis has increased to 566 per 100,000 over the last decade. There is a 33% possibility that CAF and lung-related disease will co-occur. However, the merging mechanism of these two diseases has not been explored. We report a case of a 61-year-old female with bronchiectasis who was admitted to our hospital with dyspnea and ankle edema. The patient was diagnosed with coronary artery-pulmonary artery fistula by coronary angiography (CAG), which was performed to rule out the possibility of coronary artery stenosis. Using the keywords "coronary artery fistula" and "bronchiectasis" to search the inpatient system of our hospital, PubMed, and Web of Science, we found that these two diseases often occur due to abnormal cardiovascular and pulmonary airway connection. Previous studies also support that CAF can co-occur with bronchiectasis. Based on these findings, we explain the possible mechanism of this co-occurrence with the aim of improving diagnostic techniques and therapeutic methods.