Conclusion:
In this case, a right pulmonary artery to left atrium fistula was
diagnosed as the cause of unexplained cyanosis in 3.5 years old child.
The diagnosis was confirmed based on cardiac angiography through cardiac
catheterization, and the underlying anatomy of the pulmonary vasculature
and its relationship with the left atrium was visualized using
multi-slice CT.
This case is of significant importance because classification of fistula
does not correspond to the classifications mentioned previously in the
medical literature. Surgical repair was performed after diagnosis to
prevent the serious complications of the fistula. The patient’s
oxygenation and symptoms improved immediately after surgery and
persisted on follow-up after 6 months.