Yvonne L. Douglas, Monique R. M. Jongbloed, Wietske C. E. den Hartog, Margot M. Bartelings, Ad J. J. Bogers, Tjark Ebels, Marco C. DeRuiter, Adriana C. Gittenberger-de Groot
University Medical Center Groningen and University of Groningen.
Netherlands
International Journal of Cardiology
Int J Cardiol 2009; 134: 302-312
DOI: 10.1016/j.ijcard.2008.11.098
Abstract
Background: Normally, the inside of the left atrial (LA) body and pulmonary veins (PVs) is lined by vessel wall tissue covered by myocardium. In total anomalous pulmonary venous connection (TAPVC), no connection of the PVs with the LA body exists. These veins have an increased incidence of PV stenosis. We describe the consequences of the absent connection for the histopathology of the wall of the LA body and the PVs, and hypothesize on a mechanism predisposing to PV stenosis.
Methods and results: In 10 human neonates with TAPVC, the wall of the LA body and PVs were studied using histological and immunohistochemical techniques. As controls, 2 normal neonatal and adult hearts and 5 neonatal hearts with partial anomalous venous connection (PAPVC) or situs inversus were studied. In hearts with TAPVC no vessel wall tissue was found in the LA body and its myocardial layer was hypoplastic. No myocardial sleeve was found around the abnormally draining PVs. In hearts with PAPVC, only the non-LA draining PV lacked myocardial covering, whereas in situs inversus PVs connecting to the right-sided LA, were normally myocardialized.
Conclusion: An open connection of the PVs with the morphological LA is necessary for the presence of vessel wall tissue in the LA and myocardialization of the PVs. Absence of myocardium covering the PVs is hypothesized to enhance susceptibility to PV stenosis and prevent onset of PV originating arrhythmias. The embryonic posterior heart field may be responsible for the abnormal myocardialization and smooth muscle cell formation in TAPVC.
Category
Segmental Pulmonary Venous Disease. Without a Focus on Pulmonary Hypertension
Pulmonary Vascular Pathology
Age Focus: Pediatric Pulmonary Vascular Disease
Fresh or Filed Publication: Filed (PHiled). Greater than 1-2 years since publication
Article Access
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