Infectious endocarditis caused by Helcococcus kunzii in a vascular patient: a case report and literature review.

BACKGROUND: Helcococcus kunzii is a facultative anaerobic bacterium that was first described by Collins et al. in 1993, and was initially considered as a commensal of the human skin, in particular of lower extremities. Human infections caused by H. kunzii remain rare with only a few cases published in the pubmed database. Nevertheless recent reports indicate that this microorganism has to be considered as an opportunistic pathogen that can be involved in severe infections in human. To the best of our knowledge, we describe here the first known case of infectious endocarditis caused by H. kunzii. CASE PRESENTATION: A 79 year-old man reporting severe polyvascular medical history attended the emergency ward for rapid deterioration of his general state of health. After physical examination and paraclinical investigations, the diagnosis of infectious endocarditis on native mitral valve caused by Helcococcus kunzii was established based on Dukes criteria. MALDI-TOF mass spectrometry and 16S rDNA sequencing allowed an accurate identification to the species level of Helcococcus kunzii. The patient was successfully treated by a medico-surgical approach. The treatment consisted in intravenous amoxicillin during four weeks and mitral valve replacement with a bioprosthestic valve. After an in depth review of patient's medical file, the origin of infection remained unknown. However, a cutaneous portal of entry cannot be excluded as the patient and his General Practitioner reported chronic ulcerations of both feet. CONCLUSIONS: We describe here the first case of endocarditis caused by H. kunzii in an elderly patient with polyvascular disease. This report along with previous data found in the literature emphasizes the invasive potential of this bacterial species as an opportunistic pathogen, in particular for patient with polyvascular diseases. MALDI-TOF mass spectrometry and 16S rDNA sequencing are reliable tools for H. kunzii identification. We also sequenced in this work H.kunzii type strain 103932T CIP and deposited in the Genbank under accession number KM403387. We noticed a 14 base difference between our sequence and the original sequence deposited by Collins et al. under Genbank accession number X69837. Hopefully, the spread of next generation sequencing tools would lead to a more accurate classification of clinical strains.

Remote-controlled magnetic pulmonary vein isolation using a new three-dimensional non-fluoroscopic navigation system: a single-centre prospective study.

BACKGROUND: Catheter ablation of atrial fibrillation (AF) focuses on pulmonary vein isolation (PVI), but the procedure is associated with significant X-ray exposure. Few data exist concerning the combination of remote magnetic navigation (RMN) and a new three-dimensional non-fluoroscopic navigation system (Carto(®) 3), which facilitates precise catheter navigation and limits X-ray exposure. AIMS: To assess the efficacy and extent of fluoroscopic exposure associated with the combination of RMN and the Carto 3 system in patients requiring AF ablation. METHODS: Between January and September 2011, catheter ablation was performed remotely using the Carto 3 system in 81 consecutive patients who underwent PVI for symptomatic drug-refractory AF. The radiofrequency generator was set to a fixed power ≤ 35W. The primary endpoint was wide-area circumferential PVI confirmed by spiral catheter recording during ablation and including additional lesion lines (left atrial roof and coronary sinus defragmentation) or complex fractionated atrial electrograms for persistent AF. Secondary endpoints included procedural data, complications and freedom from atrial tachycardia (AT)/AF. RESULTS: Mean age was 60 ± 9 years; 20% were women; 73% had symptomatic paroxysmal AF; 27% had persistent AF. The CHA2DS2-VASc score was 1.2 ± 1. Median procedure time was 3.5 ± 1 hours; median total X-ray exposure time was 13 ± 7 minutes; transseptal puncture and catheter positioning took 8 ± 4 minutes, left atrium electroanatomical reconstruction 1 ± 4 minutes and catheter ablation 3.5 ± 5minutes. Recurrences were AT (n=3; 3.7%), paroxysmal AF (n=8; 9.9%) and persistent AF (n=4; 4.9%); redo ablation was performed in these 15 (19%) patients. After a median follow-up of 15 ± 6 months and a single procedure, 71% of patients were free of symptoms; 84% remained asymptomatic after two procedures. CONCLUSIONS: RMN with irrigated catheters combined with the Carto 3 system can be effectively performed in patients requiring AF ablation with minimal use of fluoroscopy, but larger randomized studies are warranted.