Pulmonary Atresia Intact Ventricular Septum

Pulmonary atresia with intact ventricular septum (PAIVS) is a complex congenital heart defect characterized by pulmonary valvular atresia. As such, the colour box presented below does not show any passage of blood flow through the valve. The disease is PGE dependent - ductal dependent - to allow adequate pulmonary circulation. Patients may have various presentations, with myocardial sinusoids complicating the course of their management. More on PAIVS here.

More information on PAIVS: Pulmonary atresia with intact ventricular septum is a complex condition where there is dependent ductal pulmonary circulation. As such, these infants need urgent exposure to prostaglandin to maintain ductal patency and pulmonary blood flow. They will be cyanotic, considering that the right to left shunt is obligatory at the atrial level, introducing deoxygenated blood in the systemic circulation. Saturation to be aimed are >80%, outlining that there is adequate pulmonary blood flow and oxygenated blood coming back to the left atrium and mixing with the right to left shunt via the inter-atrial communication. This condition is of particular interest, considering that there is a risk in a subcategory of infants with PAIVS of persistent sinusoids, possibly stealing from the coronary circulation. Indeed, depending on the tricuspid valve competency, the intra-RV pressure may be extremely high during the early fetal life. Because of this, these remnant embryological channels (sinusoids) may stay patent and connect the RV cavity to the coronary system. This may lead to severe coronary steal upon decompression of the RV. As such, these patients are at risk of severe myocardial ischemia and there is a requirement to go to the cath lab before any surgery in order to delineate if there is indeed sinusoids connecting to the coronary circulation, before attempting any intervention. Depending on the RV size, the RVOT configuration and the presence or absence of sinusoids, these patients will have different approaches for their interventions. They may require single ventricular repair because of the above considerations.

Case 1

Case 2

Pulmonary atresia with intact ventricular septum. Severe tricuspid valve annular hypoplasia. Unrestrictive secundum atrial septal defect, with a prominent and floppy septum primum. Severe right ventricular hypoplasia. Small branch pulmonary artery. Patent ductus arteriosus of pulmonary atresia type - tortuous, left to right. Coronary fistulas (sinusoids) within the right ventricle.

PAIVS presentation prepared by Laila Wazneh (NNP) and Dr Shiran S Moore (NHCR fellow) at Montreal Children's Hospital