The conduction system in hearts with pulmonary atresia and intact ventricular septum.
BACKGROUND
Although a regular course of the conduction system is anticipated in hearts with pulmonary atresia and intact ventricular septum (PAIVS), it has never been demonstrated anatomically. In view of one of the surgical options in repair being debulking of the right ventricular wall, it is important to establish the location of the major conduction pathways.


METHODS
Four hearts belonging to fetuses aged 18, 20, 22, and 29 weeks were examined. Entire hearts were serially sectioned and step sections were stained. The sinus node and atrioventricular conduction bundles were identified and their locations described.


RESULTS
The conduction system in hearts with PAIVS is similar to that in normal hearts, although there was a minor variation in one of them. This was a heart affected by Ebstein malformation of the tricuspid valve. In this case, the right bundle branch terminated abruptly soon after its origin.


CONCLUSIONS
Confirmation of the regular course of the cardiac conduction system is important to the development of strategies for surgical repair of PAIVS.
Department of Paediatrics, Imperial College, Faculty of Medicine, London, United Kingdom.
Aneel
A
Ansari
Diane
D
Goltz
Karen Patricia
KP
McCarthy
Andrew
A
Cook
Siew Yen
SY
Ho
D004437:Ebstein Anomaly / Q000196:embryology / Q000473:pathology; D005333:Fetus / Q000473:pathology; D006329:Heart Conduction System / Q000196:embryology / Q000473:pathology*; D006346:Heart Septum / Q000196:embryology / Q000473:pathology*; D006352:Heart Ventricles / Q000196:embryology; D006801:Humans; D018633:Pulmonary Atresia / Q000150:complications / Q000196:embryology / Q000473:pathology*