Background: Conotruncal defects constitute one of the major categories of congenital heart disease. Our understanding of how these defects develop has been derived from knowledge of the role of neural crest cells in heart development. However, recent studies have revealed a role for the myocardium in the formation of both the arterial and venous poles of the heart.
Aim: To identify congenital heart defects that associate anomalies of the arterial and venous poles.
Methods: From a database spanning 27 years, we identified those patients with conotruncal defects associated with an anomalous pulmonary venous connection (APVC; total or partial). Patients with atria isomerism or atrioventricular septal defects were excluded. Patient files were reviewed for clinical presentation, family history, diagnostic and surgical procedures, and outcome.
Results: We identified 23 patients with conotruncal defects and APVC. Conotruncal defects were as follows : common arterial trunk, n=7; tetralogy of Fallot, n=5; discordant ventriculoarterial connections, n=4; interrupted aortic arch, n=2; subarterial ventricular septal defect, n=2; double outlet right ventricle, n=2; and right pulmonary artery from ascending aorta, n=1. Nine patients had total APVC and 14 patients had partial APVC. Recurrence of the cardiac defects in siblings was observed in three families.
Conclusion: Our findings suggest that congenital heart defects that associate anomalies of the arterial and venous poles may have a common embryology, which results from a myocardial defect.