Can atrioventricular septal defects exist with intact septal structures?

Area of Science:

• Cardiology
• Pediatric Cardiology
• Medical Imaging

Background:

• Atrioventricular septal defects (AVSD) are congenital heart conditions characterized by a common atrioventricular junction and a trileaflet atrioventricular valve.
• Typically, AVSDs involve abnormal connections between the atria and ventricles, leading to shunting of blood.
• While AVSDs without septal defects have been noted postmortem, diagnosis in living patients has been rare.

Observation:

• This study describes six pediatric patients diagnosed with AVSD and intact atrial and ventricular septa using echocardiography.
• The key echocardiographic finding was the presence of a common atrioventricular junction with a trileaflet left atrioventricular valve, despite the absence of septal communications.

Findings:

• Atrioventricular septal defects can exist without interatrial or interventricular communications.
• Cross-sectional echocardiography is effective in diagnosing the characteristic common atrioventricular junction and trileaflet valve in AVSDs with intact septal structures during life.
• The prevalence of AVSDs with intact septal structures may be underestimated.

Implications:

• This research expands the diagnostic criteria for AVSD, highlighting the importance of echocardiographic evaluation for the common atrioventricular junction even in the absence of septal defects.
• It suggests that AVSDs without septal communications are a recognized entity that can be identified pre-mortem.
• Further studies are warranted to determine the true incidence of AVSDs with intact septal structures and their clinical significance.