Anatomical Observations on 20 Cases of Total Anomalous Pulmonary Venous Connection in Calves

Abstract

Total anomalous pulmonary venous connection (TAPVC) was observed in 20 (5.3%) of 375 bovine hearts showing congenital cardiovascular anomalies. The ages at necropsy were 129 days or less, and only 4 cases survived over 2 months. The Pulmonary veins joined to form a common pulmonary vein above the atria and none of them were connected to the left atrium. The common pulmonary vein was connected to the left azygos vein, right azygos vein and coronary sinus in 11, 6 and 1 cases, respectively, while the site of anomalous connection of the common pulmonary vein was unknown in the remaining 2 cases. Thirteen cases were of isolated TAPVC without other cardiovascular anomaly with the patent foramen ovale as shunting channel for the left atrium, and many of them had enlarged and hypertrophic the right atrium and ventricle. Seven cases with associated cardiovascular anomalies showed various anatomic features in the heart.