Right bundle branch in ventricular septal defects.

This article systematically reviews the anatomical variations of the right bundle branch (RBB) in normal hearts and different subtypes of ventricular septal defects (VSDs), including perimembranous inlet and outlet defects and tetralogy of Fallot (ToF). It highlights that in normal hearts, the RBB courses posterior to Lancisi's muscle, whereas in perimembranous outlet VSDs—especially in ToF—the RBB typically runs about 2 mm anterior to the medial papillary muscle (MPM). These positional differences are critical for surgical planning to minimize conduction system injury during VSD closure. The study also discusses surgical techniques, such as a continuous "shallow-bite" suturing method, designed to reduce postoperative conduction disturbances like right bundle branch block (RBBB). Understanding these anatomical relationships aids surgeons in optimizing VSD repair while preserving cardiac conduction integrity.