Cardiac dysfunction, arrhythmia, and hepatic fibrosis are well-known complications after right heart bypass surgery in patients with single-ventricle physiology. However, little is known about coronary arterial fistulae, and only a few reports have been published. This study aimed to elucidate the clinical characteristics of these rare coronary arterial fistulae that developed as complications in cases of single-ventricle physiology after right heart bypass surgery.

We retrospectively investigated the clinical features and courses of patients who developed acquired and progressive coronary arterial fistulae after right heart bypass surgery in our hospital.

We identified three cases of coronary arterial fistulae out of 21 patients who underwent right heart bypass surgery. All three cases underwent cardiac catheterisation for post-operative evaluation and were administered pulmonary vasodilators of phosphodiesterase type V inhibitors, antiplatelet, anticoagulation, and diuretics. Moreover, they had common clinical features such as right-dominant single ventricle and long-term exposure to chronic hypoxia. Serial angiograms revealed acquired and progressive coronary arterial fistulae. In addition, coronary arterial fistulae contributed to their symptoms of heart failure.

Patients with chronic hypoxia and dominant right ventricle, who are treated with phosphodiesterase type V inhibitors, should be followed up after right heart bypass surgery to monitor the possible development of coronary arterial fistulae. Moreover, the indication for pulmonary vasodilators in single-ventricle physiology after right heart bypass surgery should be optimised to avoid adverse effects.