To determine whether it is the preservation of the moderator band (MB) and its ramification during modified repair of tetralogy of Fallot that accounts for the low incidence of postoperative right bundle branch block (RBBB) we studied 15 dogs: Ten dogs (Group A) underwent a modified right ventriculotomy (RVY), which is lateral and shorter than the standard oblique incision, and 5 dogs (Group B) underwent a standard oblique RVY, taking special care not to damage the MB or its branches. The appearance of RBBB was looked for both by continuous surface ECGs and by bipolar electrograms from 6 preselected sites on the right ventricular surface. Complete RBBB failed to develop in any of the dogs in Group A and in 4 of the 5 dogs in Group B. In Group A each dog served as its own control by transecting its MB after completion of the RVY. This resulted in immediate appearance of complete RBBB. We conclude that as long as the MB or its Purkinje ramifications are preserved, no RBBB will develop, regardless of the extent of the RVY.
|Number of pages||3|
|Journal||Japanese Heart Journal|
|Issue number||Suppl. 1|
|State||Published - 1982|