Infective Endocarditis Associated with Atrial Septal Defect in an Intravenous Drug Abuser: A Case Report

Atrial septal defect (ASD) is a common congenital abnormality, which accounts for 20-40% of all the adult patients with congenital heart diseases. Due to the slow velocity of shunt flow, ASD has a negligible risk for infective endocarditis (IE). However, intravenous drug abuse (IVDA) is a potential cause for IE. IE remains a diagnostic and therapeutic challenge. Our case report demonstrates the atypical presentation of IE in an ASD patient. The diagnosis was made on the basis of modified Duke criteria, and blood cultures were found out to be positive for methicillin-resistant Staphylococcus aureus (MRSA). The treatment for IE was completed in six weeks with full recovery, and the patient underwent a surgery for ASD closure. This case highlights that IE should not be overlooked in ASD patients and that a high index of suspicion, in addition to proper antibiotic therapy, is lifesaving. Also, follow-up, along with rehabilitation measures, should be taken for patients with a history of drug abuse in order to prevent the risk of reinfection.