Agenesis of the Inferior Vena Cava

Agenesis of the inferior vena cava is a rare malformation. Its most common cause is dysgenesis during embryogenesis, but it may also be related to intrauterine or perinatal thrombosis. It is usually asymptomatic, associated or not with other congenital malformations and may be related to increased risk of chronic venous insufficiency and deep vein thrombosis, especially in young individuals. Diagnosis is often incidental, during abdominal surgery or radiological procedures. We reported five cases of agenesis of the inferior vena cava detected during electrophysiological procedures. DEsCrIPtOrs: Electrophysiology. Cardiovascular abnormalities. Vena cava, inferior. 1 Medicine Academic at Universidade Federal de Ciências da Saúde de Porto Alegre. Porto Alegre, RS, Brazil. 2 Master. Cardiologist Physician and Electrophysiologist at Instituto de Cardiologia/Fundação Universitária de Cardiologia. Porto Alegre, RS, Brazil. 3 Doctor. Cardiologist Physician and Electrophysiologist at Instituto de Cardiologia/Fundação Universitária de Cardiologia. Porto Alegre, RS, Brazil. 4 Doctor. Cardiologist Physician and Electrophysiologist at Instituto de Cardiologia/Fundação Universitária de Cardiologia. Porto Alegre, RS, Brazil. 5 Cardiologist Physician and Trainee at Electrophysiologist Service of Instituto de Cardiologia/Fundação Universitária de Cardiologia. Porto Alegre, RS, Brazil. 6 Doctor. Cardiologist Physician and Head of Electrophysiology Service of Instituto de Cardiologia/Fundação Universitária de Cardiologia. Porto Alegre, RS, Brazil. Correspondence to: Gustavo Glotz de Lima. Av. Princesa Isabel, 370 – Porto Alegre, RS, Brazil – CEP 90620-000 E-mail: [email protected] Received on: 9/5/2012 • Accepted on: 11/15/2012 rEsUMO Agenesia da Veia Cava Inferior Agenesia da veia cava inferior é uma malformação rara. Sua causa mais comum é a disgenesia durante a embriogênese, mas também pode estar relacionada a trombose intrauterina ou perinatal. Normalmente é assintomática, em associação, ou não, com outras malformações congênitas, e pode cursar com maior risco de insuficiência venosa crônica e trombose venosa profunda, especialmente em jovens. Seu diagnóstico frequentemente é acidental, durante cirurgias abdominais ou procedimentos radiológicos. Relatamos cinco casos de agenesia da veia cava inferior detectada durante procedimentos eletrofisiológicos. DEsCrItOrEs: Eletrofisiologia. Anormalidades cardiovasculares. Veia cava inferior. Case Report t he electrophysiological study is an invasive test used to diagnose heart rhythm and conduction disorders. The test can be used to measure atrioventricular conduction intervals, clarify arrhythmogenic mechanisms, and evaluate antiarrhythmic agent efficacy. Currently, it is used to identify and map re-entrant circuits and ectopic foci for subsequent treatment with catheter ablation. Therefore, the electrophysiological test has diagnostic, therapeutic, and prognostic value. Access to the heart is usually attained through a femoral or subclavian venipuncture to insert a catheter into the heart chambers. Agenesis of the inferior vena cava is generally an asymptomatic condition that may be unknown to the patient, and can occur in approximately 0.5% of the population.1 During electrophysiological procedures, catheter progression difficulties in the cephalad direction raise the possibility of this anomaly; therefore, manoeuvres are required to confirm the presence of agenesis. The present study reports on five patients who were admitted to the Electrophysiology Laboratory at the Instituto de Cardiologia do Rio Grande do Sul to undergo ablation and electrophysiological procedures, during which these patients were diagnosed with agenesis of the inferior vena cava.