Double outlet right ventricle: experimental morphogenesis in the chick embryo heart

Area of Science:

• Developmental Biology
• Cardiovascular Embryology
• Congenital Heart Defects

Background:

• Double outlet right ventricle (DORV) is a complex congenital heart defect.
• Understanding the embryological origins of DORV is crucial for diagnosis and treatment.
• Previous research has focused on various etiological factors, but the precise developmental mechanisms remain under investigation.

Purpose of the Study:

• To experimentally induce DORV in chick embryos.
• To investigate the role of the posteromedial conus incorporation in normal heart development.
• To characterize the resulting malformations and their embryological basis.

Main Methods:

• Experimental induction of DORV in chick embryos using a ligature around the caudal end of the conus arteriosus.
• Manipulation of ligature placement timing and duration at specific developmental stages (17-18 and 22).
• Analysis of resulting cardiac morphology at mature heart stages.

Main Results:

• Consistent production of DORV when the ligature remained until the mature heart stage.
• Successful induction of DORV in two-thirds of cases when the ligature was in place for 24 hours.
• Identification of two distinct DORV types: anterior-posterior and side-by-side infundibula, each associated with specific ventricular septal defects (VSDs).

Conclusions:

• DORV is fundamentally an infundibular malformation.
• The study elucidates two primary types of infundibular relationships in DORV.
• The findings highlight the distinct embryological origins of the crista supraventricularis and the infundibular septum in DORV.