The congenital heart defect in which all four chambers are in communication with each other is known as which condition?

The congenital heart defect in which all four chambers are in communication with each other is known as which condition?

• A. Tetralogy of Fallot
• B. Complete atrioventricular septal defect
• C. Transposition of the great vessels
• D. Coarctation of the aorta

Answer: (B)

This item tests recognition of a defect where the four heart chambers communicate through a single AV canal due to failure of the endocardial cushions to fuse. In a complete atrioventricular septal defect, there is a primum atrial septal defect and an inlet-type ventricular septal defect, all connected by a common AV valve rather than separate mitral and tricuspid valves. This creates direct communication among both atria and both ventricles. The other conditions involve different anatomical arrangements: tetralogy of Fallot has a VSD with overriding aorta and pulmonary stenosis but not a single four-chamber communication; transposition of the great vessels features ventriculoarterial discordance with parallel circulation rather than an all-chamber connection; coarctation of the aorta is a narrowing of the aorta and does not describe four-chamber communication. Therefore, the defect with communication among all four chambers is complete atrioventricular septal defect.

This item tests recognition of a defect where the four heart chambers communicate through a single AV canal due to failure of the endocardial cushions to fuse. In a complete atrioventricular septal defect, there is a primum atrial septal defect and an inlet-type ventricular septal defect, all connected by a common AV valve rather than separate mitral and tricuspid valves. This creates direct communication among both atria and both ventricles. The other conditions involve different anatomical arrangements: tetralogy of Fallot has a VSD with overriding aorta and pulmonary stenosis but not a single four-chamber communication; transposition of the great vessels features ventriculoarterial discordance with parallel circulation rather than an all-chamber connection; coarctation of the aorta is a narrowing of the aorta and does not describe four-chamber communication. Therefore, the defect with communication among all four chambers is complete atrioventricular septal defect.