Tetralogy of Fallot (TOF) with pulmonary atresia is a very rare congenital heart disease and it is difficult to carry out antemortem definitive diagnosis. This condition is characterized by the absence of physiological antegrade pulmonary blood flow, and blood supply is alternatively supplied to the lungs from the systemic arterial circulation via major aortopulmonary collateral arteries, the ductus arteriosus or bronchial arteries. Here, we describe using echocardiography, cardiac catheterization, and cardiac computed tomography (CT) to diagnose TOF with pulmonary atresia in a dog.

Radiography could assess pulmonary vessels, right ventricular overload, and other soft tissues; however, VSD, the absence of pulmonary blood flow and intracardiac status, were more confirmed by echocardiography. Cardiac angiography revealed the aorta, pulmonary atresia with a pulmonary trunk and no left and right pulmonary arteries, and lung vessels. Aortic overriding was best confirmed by 3-dimensional cardiac CT. The existence of a network of small collateral vessels in the lungs was suggested by cardiac catheterization and CT.

The prognosis of VSD with pulmonary atresia varies and depends on the quality of the pulmonary blood supply. Right heart failure seems to be the most important influence on prognosis. Although echocardiography, cardiac catheterization and CT are useful for definitive diagnosis, methods of determining prognosis have not yet been established. We hope that these investigative modalities will be applied more frequently and that clinical evidence will be amassed to further improve the lives of animals with extreme TOF.