Gerbode defect resulting from ineffective treatment of infective endocarditis: a case report

Infective endocarditis is a common medical complication in patients with intravenous drug use (IVDU). staphylococcal infection is the predominant pathogen in left-sided endocarditis. Cardiac abscesses are more common in prosthetic valves. Should they rupture, they often create fistulous tracts in addition to prosthetic valve dehiscence, conduction abnormalities, and acute coronary syndrome.

A 51-year-old man with history of IV drug use, methicillin-susceptible Staphylococcus aureus (MSSA) endocarditis, and bovine aortic valve replacement was treated for MSSA bacteremia and was discharged on dalbavancin. The transesophageal echocardiogram (TEE) was negative for abscess or vegetation. Three days later, he presented with fever, worsening mental status, and neurologic deficits with infarcts in the brain, lungs, spleen on imaging. TEE was negative for vegetation or abscess. After transfer to a quaternary care center four days later, TEE showed a large aortic root abscess that eroded the membranous ventricular septum resulting in a Gerbode defect. Then, he sustained a non-shockable rhythm cardiac arrest. The patient was transferred to the cardiac ICU where emergent TEE showed complete dehiscence of the septum and a loosely attached prosthetic aortic valve. After a second cardiac arrest and resuscitative efforts, the patient expired.

This case highlights that inadequately treated infective endocarditis can rapidly progress and cause serious complications. If patients with prosthetic valves develop bacteremia and have negative TEEs, retrospectively-gated CTs should be obtained to evaluate for perivalvular extensions. Currently, there have been no published studies demonstrating patients with infective endocarditis who were treated with Dalbavancin that progressed to fistulous tracts. Further research is required to investigate the effectiveness of long-acting lipoglycopeptides, such as Dalbavancin, in treating infective endocarditis. This case demonstrates a rare, but a serious medical emergency that can arise in patients with prosthetic heart valves and positive blood cultures when not detected early and treated promptly.