3D reconstruction of the porcine and equine pulmonary veins, supplemented with the identification of telocytes in the horse.

The myocardial sleeve of the porcine and equine pulmonary veins were histologically investigated and reconstructed three dimensionally. Moreover, the localization of neuron cell bodies at the veno-atrial junction and alongside the myocardial sleeve was light microscopically visualized to depict the organization of nerve, myocardial and fat tissue. Finally, the presence of telocytes inside the equine pulmonary veins was demonstrated by use of transmission electron microscopy. These structures are thought to play a role in the induction of atrial fibrillation, which is frequently seen in horses, while pigs are often used as a cardiovascular model in this context. This data fills in remaining gaps in the literature concerning the histological build-up of the pulmonary veins wall in pigs and horses. In-depth knowledge on the myocardial sleeve and its surrounding cell types are important to understand the possible outcome of an ablation therapy as an atrial fibrillation treatment. In pigs and horses, the layout of the pulmonary veins wall concerning these structures is comparable to humans. However, neuron cell bodies were recovered at the veno-atrial junction in both species but not alongside the myocardial sleeve in horses.