Acute endocarditis complicated by left ventricular pseudoaneurysm with acute bloody pericardial effusion: A case...

Delay in seeking medical attention for high fever and inadequate diagnosis can lead to rapid progression of inflammation and spread to surrounding tissues and organs. Staphylococcus aureus is a common cause of systemic infections, and infectious endocarditis can swiftly become severe; therefore, careful management is required.

A 54-year-old woman was admitted to our hospital with high fever and progressive loss of consciousness. Meningitis was suspected, and antibiotic treatment was initiated. Blood culture revealed methicillin-sensitive Staphylococcus aureus. Subsequently, the patient developed hypotension, bradycardia, and cardiac arrest and underwent emergency cardiopulmonary resuscitation.

Transesophageal echocardiography performed during the procedure revealed significant vegetation at the posterior leaflet of the mitral valve, an abscess at the valve annulus, and a pseudoaneurysm of the left ventricular posterior wall.

The patient underwent emergency small incision pericardiotomy drainage, and her blood pressure and heart rate stabilized. After pericardial drainage, acute renal failure, fulminant hepatitis, and disruption of coagulation function were observed, and she was treated with plasma exchange therapy and intravenous immunoglobulin. Resection of the huge vegetation, debridement, patch closure of the ventricular perforation, and mitral valve replacement were performed.

Surgical findings showed massive vegetation in the posterior leaflet of the mitral valve, an annular abscess in the posterior leaflet of the mitral valve connected to the left ventricular posterior wall, and a pseudoaneurysm. Postoperatively, her pseudoaneurysm resolved and her cardiac function stabilized, while circulatory failure due to bacteremia progressed, and she gradually developed acidosis and unstable blood pressure. Plasma exchange and continuous hemodiafiltration were continued; however, she died of progressive multiorgan failure.

Staphylococcus aureus bacteremia can cause fatal complications. Even when symptoms of meningitis are suspected, it is essential to examine the patient for endocarditis. Delayed diagnosis can lead to fatal endocarditis-related complications.