Persistent left superior vena cava: A disconcerting finding for interventionist.

Area of Science:

• Cardiology
• Vascular Anatomy
• Medical Case Reports

Background:

• Persistent left superior vena cava (PLSVC) is a common congenital anomaly of the thoracic venous system, often asymptomatic.
• PLSVC typically coexists with a normal right-sided superior vena cava (SVC).
• Diagnosis is frequently incidental during invasive procedures like central venous catheterization or pacemaker implantation.

Observation:

• A patient presented for pacemaker implantation with a known PLSVC.
• Difficulty was encountered advancing the pacing lead to the right ventricular apex due to the anomalous venous anatomy.
• Attempted right subclavian vein access revealed an absent right SVC, necessitating procedure abandonment.

Findings:

• This case presents a rare variant of PLSVC associated with a complete absence of the right SVC in a structurally normal heart.
• The anomalous anatomy significantly complicated the planned transvenous pacemaker lead placement.
• Successful lead placement was ultimately achieved via epicardial means.

Implications:

• Highlights the critical importance of thorough pre-procedure venous anatomical assessment, especially in patients with known or suspected venous anomalies.
• Underscores the potential challenges PLSVC, particularly rare variants, can pose during cardiovascular interventions.
• Emphasizes the need for alternative strategies like epicardial lead placement when standard transvenous approaches are compromised by venous anomalies.