Rarеly used method to diagnose infective endocarditis

Abstract

Introduction: Infective endocarditis (IE) is a life-threatening inflammation of the endocardium most commonly affecting the heart valves. Both left-sided and right-sided involvement of the heart are re­ported with left-sided pathology leading to more severe complications. Materials and Methods: This is a case of a patient who was admitted to the hospital with intermit­tent fever for two months. He was previously treated with antibiotics and showed temporary improve­ment. The patient underwent surgical aortic valve replacement and ascending aortic prosthesis in 2011 after an acute aortic dissection Stanford type A. A mechanical valve and aortic allograft were used respectively. Results: Clinical examinations suspected infective endocarditis with unknown location. Different blood tests were performed including a blood culture test which confirmed the presence of alpha hae­molytic streptococcus. In similar cases transoesophageal two-dimensional echocardiography (TOE) and transthoracic two-dimensional echocardiography (TTE) play a crucial role in confirming the di­agnosis. In this case, however, none of them showed any signs of infective endocarditis. Following the European society of Cardiology (ESC) guidelines - a Positron emission tomography-computed to­mography (PET/CT) was performed which showed increased activity in the region around the pros­thetic valve and the anastomosis between the allograft and aortic arch. A few more areas were spotted in the middle graft section, all of which indicated an inflammatory process. Signs from other organs indicating infection were registered - diffusely increased splenic (FDG) uptake as well as increased bone-marrow activity. The patient was treated with antibiotics including Amoxiclav and Ciprofloxa­cin, and his condition quickly improved, consequently he is currently alive. Despite being infrequent­ly used worldwide, that is the first known case in Bulgaria of IE diagnosed with PET/CT. Conclusion: PET/CT was the only method confirming the diagnosis in this case. It may be used in the future as a non-invasive method for diagnosing IE.