Persistent left superior vena cava draining to left atrium with normal coronary sinus

Area of Science:

• Cardiovascular Embryology
• Congenital Heart Anomalies

Background:

• Persistent left superior vena cava (PLSVC) is a rare congenital anomaly.
• Typically, PLSVC drains into the coronary sinus, which then empties into the right atrium.
• Coexistence with a normally functioning coronary sinus is exceptionally uncommon.

Observation:

• A case report detailing an unusual embryological anomaly: PLSVC terminating directly into the left atrium.
• The anomaly was incidentally discovered during permanent pacemaker implantation following a second surgery for recurrent left atrioventricular valve regurgitation.
• Preoperative coronary angiography did not reveal dilation, contributing to the anomaly being missed during initial surgical assessment.

Findings:

• The patient presented with a persistent left superior vena cava draining into the left atrium, despite having a normal coronary sinus.
• The anomaly remained undiagnosed during a prior cardiac operation, underscoring diagnostic challenges.
• The coronary sinus was not dilated, which complicated its identification via standard preoperative imaging.

Implications:

• Undiagnosed PLSVC terminating in the left atrium poses risks of cyanosis and neurological complications due to potential right-to-left shunting.
• Early diagnosis is crucial for appropriate surgical management, potentially involving patch repair or other corrective procedures.
• Increased awareness and vigilance are necessary among clinicians managing complex congenital heart conditions and during cardiac interventions.