P22 AN UNEXPECTED DIAGNOSIS; GEMELLA MORBILLORUM, A POORLY KNOWN KILLER

Abstract

Abstract 58–year–old woman, previous smoking habit. In medical history holosystolic murmur since childhood. At echocardiogram performed in 2019: "VS with preserved FE, mild–to–moderate IA, likely perimembranous DIV." No major comorbidities. In June 2021, she was admitted to the Mestre NICU for paroxysmal complete atrioventricular block. On echocardiogram, mild worsening of IA was described, with a sub–valvular shunt and doubtful aortic bicuspidia. At 24 hours after admission, the patient underwent definitive bicameral PM implantation. In light of the clinical and echocardiographic suspicious, we began to think of a possible organic genesis of the event; a hypothesis supported by the finding of serotin fever and a dental examination with dental hygiene that the patient reported having performed a month earlier. So, on suspicion of an infectious genesis, cold blood cultures were requested and found to be positive for Gemella Morbillorum. The endocarditis hypothesis was confirmed by performing a TE echo and PET/CT scan. Antibiotic therapy was then set up, and an infectious source was subsequently searched for, through a CT scan of the dental arches, which was positive for foci of periodontopathy, and through a rectosigmoidocolonoscopy finding an adenoma with high–grade dysplasia. HOT TOPIC: infective endocarditis is a disease with a high risk of mortality and complications. Among the complications, conduction disturbances are relatively rare. A–V block is often paroxysmal, driven by inflammation, and therefore potentially reversible. Hence, the paramount importance of performing a thorough echocardiogram and resolving any suspicions before referring the patient for definitive device implantation. The case also turns out to be particularly interesting not only for the onset of symptomatology but also for the etiology of the latter. In fact, the microorganism responsible is not among the most frequent germs but represents a rare cause of which there are few cases described in the literature. The main infectious source in humans is the dental system, but several studies have shown a correlation between Gemella morbillorum and rectal colon cancer. Ultimately, the above case represents a typical example of how a "easy" hospitalization for a conduction disorder can actually reveal a much more complex pathology.