Understanding Elevated Hemoglobin and Right Pulmonary Artery-LA Fistula: Case Studies and Interventions

Case Summary of Two Patients with Pulmonary Arteriovenous Fistulas

Patient 1: Initial Findings and Diagnosis

A patient presented with elevated hemoglobin (18.7 gr/dL), high hematocrit (53.4%), increased lymphocytosis (51%), and low MCHC (28.6). His electrocardiogram (ECG) was normal. A chest X-ray showed a double shadow, cardiomegaly, and decreased pulmonary vascular markings. Due to symptoms of cyanosis and low oxygen saturation, the patient underwent a transthoracic echocardiography (TTE). The TTE revealed no intracardiac defects but noted a dilated right pulmonary artery (RPA), which was larger than the left pulmonary artery (LPA). A large orifice in the left atrium (LA) was found, measuring 15 mm.

A contrast TTE (CTTE) indicated delayed filling of the left heart and an extracardiac shunt. A contrast-enhanced computed tomography angiography (CECTA) identified the dimensions of the dilated RPA and its connection to the aneurysmal right inferior pulmonary vein (RIPV). Following these findings, the medical team recommended urgent endovascular intervention to close the RPA-LA communication.

The patient underwent the procedure using an AMPLATZER™ Septal Occluder device. Post-intervention, the patient’s oxygen saturation increased from 80% to 92%, and angiography confirmed a good device position.

Patient 2: Symptoms and Treatment

A 13-year-old male arrived at the emergency department with dyspnea and palpitations. His symptoms had progressed, and he exhibited central cyanosis and oxygen saturation of 65%. Laboratory tests showed significantly high hemoglobin levels (22 g/dL) and abnormal chest X-ray results.

Repeat TTE indicated a larger RPA than LPA, suggesting an abnormal extracardiac shunt. CT angiography showed a dilated RPA connected to an aneurysmal RIPV. These findings indicated a pulmonary arteriovenous fistula and an RPA to LA fistula.

Considering the patient’s severe symptoms, he was deemed a candidate for percutaneous intervention. In the catheterization lab, the RPA-LA fistula was confirmed via angiography. The connection was occluded with an Amplatzer Septal Occluder device without complications. Post-procedure evaluations showed a good device position, and the patient underwent successful ablation for recurring arrhythmias.

Conclusion

Both patients showed structural abnormalities leading to pulmonary arteriovenous fistulas. Effective diagnostic imaging and timely intervention improved their conditions, demonstrated by increased oxygen saturation and the absence of abnormal contractions post-treatment.