Radiofrequency catheter ablation in infants and children

Background: Diagnosis and treatment of paediatric arrhythmias remain challenging. Antiarrhythmic - drugs beta-blockers, class Ic and class III drugs, were the only treatment available for many years. Radiofrequency catheter ablation (RFCA) was introduced for adult patients in 1981 and has been used for children since 1989. Questions remain regarding the efficacy and safety in paediatrics.Method: A retrospective analysis of patient records, 12 years and younger, at Leuven University Hospital, from January 2011 - July 2015 was performed.Results: From January 2011 - July 2015, 51 ablations were performed in 44 patients ≤12 years of age. Mean age was 7 years (range 3 weeks - 12 years), 11 (21.5%) ≤2 years; mean weight 16.5kg (range 3.4 - 56kg); average screening time 33.5min (SD } 22.7). Echocardiography was normal in 32 (72.7%) of patients. All cases were done under general anaesthesia. Diagnosis at electrophysiological study: Atrioventricular reentry tachycardia in 26 (50.9%), atrial ectopic tachycardia in 7 (13.7%), intra-atrial reentry tachycardia in 5 (9.8%), atrioventricular nodal reentry tachycardia in 11 (21.6%) and ventricular tachycardia in 2 (3.9%). RFCA was successful in 44 (86.3%) with recurrence rate of 13.7%. No signifi cant complications were noted.Conclusion: RFCA can be performed safely and effectively in even the very young. Recurrence and complication rates are similar to those reported in adults. RFCA should be the treatment of choice in selected paediatric patients

Combination therapy versus monotherapy: a randomised pilot study on the evolution of inflammatory parameters after ventilator associated pneumonia [ISRCTN31976779]

INTRODUCTION: Combination antibiotic therapy for ventilator associated pneumonia (VAP) is often used to broaden the spectrum of activity of empirical treatment. The relevance of such synergy is commonly supposed but poorly supported. The aim of the present study was to compare the clinical outcome and the course of biological variables in patients treated for a VAP, using a monotherapy with a beta-lactam versus a combination therapy. METHODS: Patients with VAP were prospectively randomised to receive either cefepime alone or cefepime in association with amikacin or levofloxacin. Clinical and inflammatory parameters were measured on the day of inclusion and thereafter. RESULTS: Seventy-four mechanically ventilated patients meeting clinical criteria for VAP were enrolled in the study. VAP was microbiologically confirmed in 59 patients (84%). Patients were randomised to receive cefepime (C group, 20 patients), cefepime with amikacin (C-A group, 19 patients) or cefepime with levofloxacin (C-L group, 20 patients). No significant difference was observed regarding the time course of temperature, leukocytosis or C-reactive protein level. There were no differences between length of stay in the intensive care unit after infection, nor in ventilator free days within 28 days after infection. No difference in mortality was observed. CONCLUSION: Antibiotic combination using a fourth generation cephalosporin with either an aminoside or a fluoroquinolone is not associated with a clinical or biological benefit when compared to cephalosporin monotherapy against common susceptible pathogens causing VAP

La troponine T ultrasensible : un nouvel outil diagnostic pour le médecin sportif?

peer reviewedIntroduction : Le risque d’accidents cardiaques ou de mort subite après effort physique intense est bien connu. Ces évènements indésirables se produisent souvent chez des sujets présentant une maladie coronarienne asymptomatique et ignorée. Néanmoins, vu ce risque, l’American Heart Association recommande de réaliser un screening cardiovasculaire chez les athlètes de tout âge. Dans cette optique, le dosage de marqueurs cardiaques de nouvelle génération, plus sensibles, comme la troponine T ultrasensible (hsTnT) peut certainement apporter des informations très intéressantes par la détection de dommages myocardiques mêmes mineurs. Matériels et méthodes : Des 20 sujets masculins volontaires âgés de 22.36±2.02 années, sédentaires, 8 ont dû être exclus (abandon, malaise à l’effort...). La VO2max a été préalablement déterminée lors d’un test à l’effort sur cycloergomètre une semaine avant le test afin de ne pas interférer avec les résultats de l’effort physique intense (EPI) pour lequel les sujets ont couru sur tapis roulant durant 1 heure à 75% de la VO2max. Quatre échantillons sanguins de 5 ml (tube hépariné-lithium) ont été prélevés : juste avant (T1), directement après (T2), 4 heures après (T3) et 24 heures après l’EPI (T4). Le dosage de hsTnT (Modular de Roche Diagnostic®) est réalisé sur du plasma par une technique d’électrocheminiluminescence. Résultats : Une augmentation statistiquement significative des résultats à T3 (p<0.01) est observée. L’élévation de la hsTnT est progressive pour atteindre un pic maximum à T3 et revenir dans les normes à T4. Le seuil critique de 0.03 ng/mL a été retenu et 75% des sujets présentent un taux supérieur à ce dernier à T3 (moyenne : 0.053 ng/mL), alors que 100% des sujets se trouvent en dessous de ce seuil à T1 (0.0041 ng/mL). Discussion - Conclusions : Ces résultats, extrêmement intéressants, suggèrent que la libération de hsTnT serait due soit à un processus physiologique de remodelage, soit à un processus irréversible de lésions au niveau des cardiomyocytes (nécrose). Il est également possible que cette élévation des troponines soit due à une libération à partir du pool cytosolique mais aussi elle peut être la conséquence de dommages membranaires potentiellement induits par le stress oxydatif. A l’issue de cette étude, nous démontrons que la hsTnT peut être un nouvel outil diagnostic dans le domaine de la cardiologie du sport

Leadless pacemaker: a new paradigm of pacing

Since the first successful pacemaker implantation in 1958, pacing remains the only reliable treatment for severe bradycardia. So far, pacing technology consists of a hermetically sealed can enclosing a battery and electronic circuits that is connected to the heart by transvenous leads to deliver the pacing therapy. Despite continuous technological improvements, cardiac pacing remains associated with a nontrivial rate of complications related to the pocket containing the can and/or to the transvenous leads. Leadless pacemakers were designed to reduce these complications. The Micra TPS of Medtronic, currently the only available leadless pacing device for human use was introduced in clinical practice in 2015. At that time, little was known about its safety and efficacy beyond/outside investigational settings. In a first part of our PhD work we assessed the efficacy and safety of this leadless pacemaker in the real-world setting. In a single center study, we showed that the Micra can be successfully implanted very safely in a challenging population when a predefined 'step by step' implantation protocol is followed. As investigator in the post-market observational registry, we contributed to the confirmation of its safety and efficacy in a large population. In dialysis patients and patients after valvular interventions, known to have higher risk of complications with the use a conventional pacing, we demonstrated the safety and efficacy of leadless pacing. Our work confirmed the low infectious risk of the leadless pacemaker after bacteremia in an elderly population. In the second part of this PhD work we wanted to optimize the implantation procedure. We confirmed the feasibility to implant the Micra device in three septal positions including the basis of the RVOT. We demonstrated that poor lower limb vascular access and the presence of a prominent septo-marginal trabeculation in the right ventricle lengthened the implant procedure. However, operator experience remains the most important determinant of the implant duration. The third part of this PhD work was dedicated to the initial evaluation of dedicated software enabling atrial mechanical sensing by the ventricular leadless pacemaker allowing VDD like physiologic pacing. In the Marvel 1 and 2 prospective multicenter studies the feasibility of AV synchronous pacing was demonstrated leading to, respectively 80% and 89.2% of AV synchrony with the use of MARVEL software. In the MARVEL Evolve study performed only in our center, we showed that the atrial sensing by the Micra device was stable over time and that the software behaved appropriately in the presence of atrial arrhythmia. Finally, we showed that the atrial function evaluated by 2D-echocardiography before the implantation was the main determinant of appropriate atrial sensing by a Micra AV (enabling AV synchrony). In conclusion, safety and efficacy of the leadless pacing were confirmed in the general population but also in challenging populations for conventional pacing. Our work validated the feasibilty to implant Micra device in different regions of the right ventricle. The current development of the Micra AV, enabling AV synchrony pacing, the ongoing research on an atrial leadless device and devices for left ventricular pacing suggest the expanding use of leadless technology in the future.status: publishe

Dual-chamber pacemaker implantation through a persistent left superior vena cava with remaining connection to the right superior vena cava

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Leadless cardiac pacemaker as alternative in case of congenital vascular abnormality and pocket infection

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Why it is important to use the correct dose of the non-vitamin K oral anticoagulants

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Twiddler syndrome causing an inappropriate implantable cardioverter-defibrillator shock

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