Abstract Title A Heart Under Siege: The Uncommon Tale of Salmonella Endocarditis Background Infective endocarditis (IE) is an infection of the innermost layer of the heart, typically caused by bacteremia localized with platelets, fibrin, and inflammatory cells that form a vegetation on a heart valve. It is generally caused by gram-positive bacteria such as Staphylococcus aureus, Streptococci viridians, Enterococci, and coagulase-negative Staphylococci, with gram-negative pathogens accounting for a small fraction of IE cases. This case report highlights the presentation, diagnostic work-up, treatment, and outcome of a patient with the rare condition of Salmonella infective endocarditis.

Case Presentation A 59-year-old male presented to the emergency department with decreased appetite, weakness, and altered mental status. He was initially diagnosed with pneumonia and Salmonella bacteremia and started on an antibiotic regimen. His hospital course was further complicated by a CT scan revealing a splenic abscess and a brain MRI showing multiple cerebral infarctions, both caused by septic emboli. Interventional radiology and neurology were consulted for these complications. A transesophageal echocardiogram (TEE) showed a 1.0 cm mitral valve vegetation. Infectious disease was consulted for antibiotic recommendations to manage the bacteremia while the patient awaited mitral valve replacement, as recommended by cardiothoracic surgery. The patient, with a significant past medical history of heart failure, diabetes, hypertension, and 30-year smoking, initially presented with tachypnea, marked leukocytosis, and elevated lactic acid levels. Blood cultures revealed Salmonella non-typhi, prompting a switch to Ceftriaxone. The patient developed encephalopathy and altered mentation, with a brain MRI showing multiple tiny infarcts. A diagnosis of Salmonella infective endocarditis with septic embolization was confirmed via TEE. A multidisciplinary approach involving interventional radiology, infectious diseases, neurology, and cardiothoracic surgery led to the decision for mitral valve replacement and concurrent coronary artery bypass grafting. Postoperatively, the patient developed atrial fibrillation, managed with an amiodarone drip and eventual cardioversion. He was discharged with an anticoagulant and follow-up plan. At follow-up visits, the patient was stable, compliant with medications, and reported no new symptoms. His INR was closely monitored, and he was educated on the importance of medication adherence following mitral valve replacement. He was referred to occupational and physical therapy, as well as neurology, for his history of cerebral infarctions.

Discussion This case underscores the importance of clinical suspicion, immediate symptom treatment, interdisciplinary collaboration, and tailored therapeutic interventions in managing rare cases of infective endocarditis. This report serves as a guide for clinicians encountering similar pathologies, highlighting the critical role of prompt microbiological investigations and tailored treatment regimens in improving patient outcomes.