Echo Rounds: Partial Anomalous Systemic and Pulmonary Venous Return.

Area of Science:

• Cardiology
• Pediatric Cardiology
• Congenital Heart Disease

Background:

• Anomalous systemic venous return is a rare congenital anomaly.
• Right-sided superior vena cava (RSVC) draining into the left atrium (LA) is an exceptionally rare variant.
• Sinus venosus atrial septal defects (VSDs) can be associated with anomalous venous drainage.

Purpose of the Study:

• To report a case of asymptomatic RSVC to LA drainage in a child.
• To investigate the mechanism preventing hypoxemia in this anomaly.
• To highlight the diagnostic utility of echocardiography in complex venous anomalies.

Main Methods:

• Case presentation of an asymptomatic child with a heart murmur.
• Diagnostic workup including echocardiography.
• Saline contrast transesophageal echocardiography (TEE) for detailed venous assessment.

Main Results:

• Diagnosis of a superior sinus venosus atrial septal defect with partial anomalous systemic and pulmonary venous drainage.
• Right superior vena cava found to override the atrial septum and drain directly into the left atrium.
• Absence of hypoxemia despite the intracardiac shunt, explained by saline contrast TEE findings.

Conclusions:

• Anomalous RSVC to LA drainage can occur asymptomatically in children.
• Specific anatomical configurations, visualized by echocardiography, can prevent systemic arterial desaturation.
• Early diagnosis and understanding of venous anomalies are crucial for pediatric cardiac care.