Periaortic Valvular Abscess Heralded by Alternating Bundle Branch Block in Prosthetic Aortic Valve Recipient

Abstract

INTRODUCTION: Prosthetic aortic valves are at higher risk for infective endocarditis. (1) We report a case of Periaortic valvular abscess leading to complete heart block in a prosthetic aortic valve recipient. CASE PRESENTATION: A 63 year-old male with history of diabetes mellitus, hypertension, COPD and a bio-prosthetic aortic valve implanted five years ago for aortic stenosis was admitted for blood cultures growing gram positive cocci in clusters. These were drawn at an outside facility where he had presented with one week history of fever and chills. The source of bacteremia was thought to be from open wounds on the lower extremities. He was started on Vancomycin for suspected Staphylococcal infection. Blood cultures drawn at admission grew Methicillin Resistant Staphylococcus aureus (MRSA). TEE (trans-esophageal echocardiography) was delayed due to patient preference but bacteremia persisted despite adequate treatment with antibiotics. Subsequently, on day 17 of admission, he developed new alternating bundle branch block followed by complete heart block (Fig-1), necessitating urgent transvenous pacing and transfer to the cardiac intensive care unit. He developed pulmonary edema and had to be intubated. A TEE was performed which revealed periaortic valvular abscess, with dehiscence of the prosthetic valve and severe paravalvular aortic regurgitation (Fig-2). He was subsequently transferred for urgent valve replacement surgery, where he died due to intra-operative hemorrhage. DISCUSSION: Prosthetic aortic valves are particularly susceptible to development of paravalvular abscess, a known complication of infective endocarditis with significantly higher mortality. The involvement of the adjacent conduction system by the abscess can lead to development of various heart blocks, a predictor of poor prognosis. (2) CONCLUSIONS: : Persistent bacteremia in presence of bioprosthetic valve and development of conduction abnormalities should prompt the diagnosis of Periaortic valvular abscess. TEE is useful to establish the diagnosis, as seen in this case.