[The double-chambered right ventricle (author's transl)]

Area of Science:

• Pediatric Cardiology
• Congenital Heart Disease
• Cardiac Anatomy

Background:

• Congenital obstructions in the right ventricle can significantly impact cardiac function.
• Understanding the anatomical variations of the moderator band is crucial for diagnosing complex heart conditions.

Observation:

• Two pediatric patients presented with right ventricular outflow tract obstruction caused by an anomalous muscular band, likely a malpositioned moderator band.
• This band divided the right ventricle into distinct high-pressure inflow and low-pressure outflow chambers.

Findings:

• The anomalous moderator band created a functional separation within the right ventricle, impacting blood flow dynamics.
• Associated cardiac anomalies, including ventricular septal defect and subvalvular aortic stenosis, were noted, highlighting the complexity of these malformations.
• Diagnostic methods like pressure recordings and dye injections are essential for accurate identification.

Implications:

• This anatomical variant can lead to severe intraoperative complications if not diagnosed preoperatively.
• Increased awareness of this condition is vital for surgeons managing patients with pulmonary stenosis and ventricular septal defects.
• Accurate diagnosis and surgical planning are critical for improving outcomes in affected children.