P1732 Congenital absence of the inferior vena cava: challenge for catheter ablation of arrhythmias via the femoral vein approach

Introduction Congenital anomalies of the inferior vena cava (IVC) are a well described entity. These anomalies include complete absence, partial absence or duplication of the IVC. They are seen more frequently in those with other congenital cardiac anomalies (0.6%–2%). This congenital condition can be discovered incidentally, or due to symptoms of associated congenital heart disease, asplenia, polysplenia, congenital kidney anomalies or deep venous thrombosis. Case report We report the case of a 48 years old man scheduled for pulmonary vein isolation due to persistent atrial fibrillation resistant to antiarhythmic drugs, symptomatic for palpitations and dyspnea on exertion. Transthoracic ecgocardiography showed mild left atrium enlargement, normal systolic LV function and no significant valve disease. The transoesophageal echocardiography revealed dilation of the left atrium and absence of thrombus in the left atrium or left appendage. Multi-slice spiral thoracic computed tomography (MSCT) was also performed before the procedure and revealed absence of the inferior vena cava and significant dilation of the azygos and hemiazygos veins with subsequent drainage into the superior vena cava. Abdominal CT showed also partial situs inversus. Pulmonary vein isolation (PVI) through femoral vein approach was cancelled and the patient was scheduled for remote magnetic navigation PVI through arterial approach. Conclusions Whether the absence of the IVC is an embryonic anomaly or the result of perinatal thrombosis with regression and subsequent congenital absence of the IVC, absence of the IVC creates difficulties for catheter ablation of arrhythmias via the femoral vein approach.