Pacemaker related infective endocarditis (PMIE) and pacemaker lead thrombosis (PMLT) are infrequent but potentially lethal complications of pacemaker (PM) therapy. Differences in clinical presentation, echocardiographic appearance and laboratory findings are usually helpful in making a confident diagnosis. On the other hand, atypical clinical and echocardiographic findings may complicate their differentiation and result in a therapeutic dilemma. We present a 70-year-old man with a permanent PM hospitalized because of a 7-day history of fever and weakness. Elevated inflammatory parameters and atypical echocardiographic findings resulted in a diagnostic dilemma between PMIE and PMLT. In this paper, we discuss the pathogenesis of these entities, their clinical presentation and therapy.
Key words: echocardiography, endocarditis, pacemaker, lead, thrombosis