Isolated anomalous left upper pulmonary vein connection in a child: a case report.

Introduction: Partial anomalous pulmonary venous connection (PAPVC) is a rare congenital heart defect where one or more pulmonary veins fail to connect to the left atrium. Left-sided PAPVC accounts for only 10% of cases, often involving the left upper pulmonary vein (LUPV). While many patients remain asymptomatic, prolonged volume overload in the right heart can lead to symptoms like dyspnea. Non-invasive imaging (TTE/CTA) is critical for diagnosis. Case presentation: An 11-year-old female presented with dyspnea and recurrent respiratory infections. Imaging revealed isolated LUPV drainage into the innominate vein via an ascending vertical vein, with right heart dilation. Surgical repair involved anastomosing the transected vertical vein to the left atrial appendage under cardiopulmonary bypass. Postoperative recovery was uneventful, with normalized pulmonary venous drainage and symptom resolution at 1-year follow-up. Clinical discussion: Left-sided PAPVC is rare (10-15% of PAPVC cases) and often asymptomatic, delaying diagnosis. Symptomatic patients require surgery to prevent right heart failure and pulmonary vascular complications. Non-invasive imaging (CTA/MRI) has replaced invasive diagnostics. Surgical success hinges on creating a gradient-free anastomosis; our on-pump approach achieved this, aligning with favorable outcomes reported in the literature. Conclusion: Early surgical intervention in symptomatic PAPVC prevents irreversible cardiac complications. Accurate imaging and meticulous surgical technique, as demonstrated in this case, are vital for optimal long-term outcomes.