Bacterial endocarditis with septic pulmonary embolism due to pacemaker lead infection

Abstract

A 69-year-old man, with a history of myocardial infarction and implantation of a permanent pacemaker because of sinus arrest, presented with periodic shortness of breath and fever. Laboratory evaluation showed an elevated C-reactive protein level and leucocytosis, but blood cultures were negative. Because computerised tomography (CT) of the thorax revealed bilateral pulmonary emboli and abdominal ultrasound was suspect for cholecystitis, the correct diagnosis and treatment were delayed. Additional transthoracic echocardiography (TTE), however, revealed a large mobile right atrial mass attached to the pacemaker lead suspect of vegetation (Fig. 1a) causing right-sided endocarditis. Fig. 1 a TTE: mobile right atrial mass attached to the pacemaker lead suspect of vegetation b TEE: large mobile mass attached to the pacemaker lead suspect of vegetation Infective endocarditis related to a pacemaker or implantable cardioverter-defibrillator lead remains a feared complication. The lead develops adherent vegetations, which are an accumulation of microorganisms, thrombocytes, fibrin and inflammatory cells, particularly prone to embolisation when large and mobile. Consequently, right heart endocarditis can lead to pulmonary embolism. Except for the complications of endocarditis, symptoms and signs are not specific, which makes diagnosis difficult [1–3]. A high level of suspicion is crucial in these patients. TTE has high specificity but only fairly good sensitivity for detection of vegetations. Transoesophageal echocardiography (TEE) has superior sensitivity (Fig. 1b) and needs to be considered to further evaluate the diagnosis when TTE is negative [1, 3]. Echocardiography and blood cultures are essential in the diagnosis of infective endocarditis. Detection of a vegetation, however, does not always imply an infectious cause [4]. In our case blood cultures did not become positive until 2 months after the patient’s initial hospital admission. Alternative imaging modalities, such as CT, magnetic resonance imaging (MRI) or nuclear imaging techniques as scintigraphy or positron emission tomography (PET), do not have a definite role in diagnosing infective endocarditis so far, but need to be evaluated [1]. The patient was scheduled for urgent open thoracotomy and pacemaker lead extraction (Fig. 2). Endocarditis was confirmed after lead removal. The patient recovered quickly after surgery. Parenteral antibiotic therapy was continued for 6 weeks. Although there is no clear recommendation for optimal timing of lead reimplantation, immediate reimplantation is discouraged because of the risk of new infectious complications [1]. In our patient, epicardial leads were reimplanted directly and successfully connected to a pacemaker device after antibiotic therapy was finished. Fig. 2 Removed pacemaker lead with vegetation