Double outlet right ventricle - the 50% rule has always been about the conus.

PURPOSE OF REVIEW: There has been much variability in the definition of double outlet right ventricle (DORV) spanning the last century. Historically, emphasis has been placed on the assignment of the great arteries to the right ventricle as a definition of DORV. In this review, we aim to underscore the importance of conal muscle, rather than rules surrounding assignment of great arteries to ventricles. We will be outlining the variability in patient anatomy that results from variations in conal muscle development in DORV, which may not fit perfectly into predefined constructs. This anatomic variability directly determines physiology and surgical repair options.

RECENT FINDINGS: There is a growing appreciation of the utility of cross-sectional imaging in complex DORV, and the generation of patient-specific 3D models with virtual reality simulations for surgical planning. These models improve the prediction of candidacy for biventricular repair and allow the mapping of complex baffle pathways preoperatively.

SUMMARY: DORV is not a disease entity in itself, but rather a vast spectrum of disorders associated with maldevelopment of conal muscle and often abnormal expansion of one the great vessels. Patient-specific 3D models will be crucial for improved surgical planning and patient outcomes.