[COVID-19 and arrhythmias]. / COVID-19 et troubles du rythme.

In the pandemic caused by the SARS-CoV2 virus, arrhythmias were not in the foreground. However, the virus seems to affect many organs and the cardiac tropism is now well known. Knowledge in this area is still far from exhaustive, but several series published concerning patients with COVID-19 find a significant proportion of arrhythmias, some of which can potentially lead to a fatal outcome. These rhythm disorders are mainly supraventricular, such as atrial fibrillation (AF) or flutter but also ventricular disorders like ventricular tachycardias (VT) ventricular fibrillation (VF) and more rarely torsades de pointe (TdP). The causes are multiple, due to the multiorgan damage caused by the virus and potential drug interactions. In addition, the question of monitoring rhythm disorders that may emerge in the medium and long term after an infection remains to be explored.

[Infections in interventional electrophysiology]. / Infections en rythmologie interventionnelle.

The implantation of pacemakers and defibrillators carries the highest risk of infection in interventional electrophysiology. The use of implantable cardiac devices is continually increasing with almost 2 million devices implanted worldwide each year. The recipients' profile may also be associated with an increased risk of infection. Several measures can be implemented to reduce the risk of device-related infection. Systematic antibiotic prophylaxis has proven to be beneficial provided that prescription modalities are respected, especially with respect to the selection of the appropriate molecule and timing of administration prior to the procedure. Despite all the precautions taken during surgery (asepsis, prophylactic antibiotic therapy….) the estimated rate of peri-procedural infection is around 2%. Device related infections are associated with a high rate of morbidity and mortality as well as substantial healthcare costs. Staphylococcus aureus (SA) and epidermidis (SE) are the pathogenic agents involved in most cases. Prevention is crucial given the difficulties in treating such infections because of the near-systematic need to remove the device and antibiotic resistance. Leadless pacemakers and subcutaneous defibrillators are potential alternatives to implantable endocardial devices, albeit with certain limitations. A group of experts has recently issued consensus paper on the prevention, diagnosis and treatment of infections associated with endocardial implantable cardiac devices.

[Transcatheter aortic valve implantation and conduction disturbances]. / Implantation percutanée de valve aortique et troubles conductifs.

Transcatheter aortic valve implantation (TAVI) is currently becoming the treatment of choice for patients with calcific aortic stenosis. Despite several technical improvements, the incidence of conduction disturbances has not diminished and remains TAVI's major complication. These disturbances include the occurrence of left bundle branch block and/or high-grade atrioventricular block often requiring pacemaker implantation. The proximity of the aortic valve to the conduction system (conduction pathways) accounts for the occurrence of these complications. Several factors have been identified as carrying a high risk of conduction disturbances like the presence of pre-existing right bundle branch block, the type of valve implanted, the volume of aortic and mitral calcifications, the size of the annulus and the depth of valve implantation. Left bundle branch block is the most frequent post TAVI conduction disturbance. Whereas the therapeutic strategy for persistent complete atrioventricular block is simple, it becomes complex in the presence of fluctuating changes in PR interval and left bundle branch block duration. The QRS width threshold value (150-160 ms) indicative of the need for pacemaker implantation is still being debated. Although there are currently no recommendations regarding the management of these conduction disturbances, the extension of TAVI indications to patient at low surgical risk calls for a standardization of our practice. However, a decision algorithm was recently proposed by a group of experts composed of interventional cardiologists, electrophysiologists and cardiac surgeons. There are still uncertainties about the appropriate timing of pacemaker implantation and the management of new onset left bundle branch block.

[Cardiac permanent pacemaker after transcatheter aortic valve implantation: A predictive and scientific review]. / Quand implanter un stimulateur cardiaque après remplacement valvulaire aortique percutané ? Revue de littérature.

Transcatheter aortic valve implantation (TAVI) is nowadays a worldwide technique in the field of treating aortic stenosis. One of the main side effects linked to the technique are mostly attached to rhythm disturbances, such as atrioventricular (AV) and intraventricular blocks. Consequently, a pacemaker implantation is often required. That implantation rate is estimated between 8 and 30%, depending on the valve chosen. Thanks to main meta analysis on the subject, it has been managed to isolate the following risks factors for AV block development: preoperative right bundle branch block (RBBB: the most powerful element), complete AV block during the procedure, male gender, a so-called porcelain aorta, the absence of previous valvular surgery, the aortic annulus size (i.e when that size is inferior to the valve's one) and the QRS duration after the procedure (the superior threshold has been set at 128ms for the Corevalve). The currently recommendations advice to implant a pacemaker are as followed: high grade AV block (in the main studies, the implantation occurs within the 5 days after the TAVI), complete and transient AV block during the TAVI, second degree AV block and RBBB associated with first degree AV block. Our article aims to review the arrhythmic issues of TAVI.

Different drug-resistant influenza A(H3N2) variants in two immunocompromised patients treated with oseltamivir during the 2011-2012 influenza season in Italy.

BACKGROUND: Monitoring the emergence of drug-resistant influenza variants is crucial in influenza surveillance programs. OBJECTIVES: Influenza A kinetics and the emergence of drug-resistant strains in hospitalized patients treated with oseltamivir were investigated. STUDY DESIGN: Sequential samples from oseltamivir-treated and -untreated hospitalized patients in the period November 2011 through April 2012 were analyzed. NA gene was sequenced in samples from oseltamivir treated patients. Clonal analysis of the viral population was performed in patients unresponsive to treatment. Viral kinetics was determined in 24 (14 immunocompromised and 10 immunocompetent) A(H3N2)-positive patients treated and 24 (10 immunocompromised and 14 immunocompetent) untreated patients. RESULTS: Viral shedding was significantly reduced in treated vs untreated immunocompromised patients (7 vs 22 days, p<0.05, respectively). Viral load decreased significantly in immunocompromised and immunocompetent treated patients as compared with immunocompromised and immunocompetent untreated patients (0.73 and 0.93 vs 0.47 and 0.45 log10/day, p<0.05). In two (8.3%) treated patients with prolonged virus shedding, the oseltamivir resistance R292K mutation was revealed. In these patients, clonal analysis of the virus population showed the presence of additional oseltamivir-resistant mutants (E119V, N294S and deletion Del247-250). CONCLUSIONS: Oseltamivir resistance is reported for the first time in A(H3N2) virus strains during the 2011-2012 influenza season. Different drug-resistant viruses emerged in hospitalized immunocompromised patients showing prolonged virus shedding.