Abstract Magnetic resonance imaging (MRI) has historically been considered contraindicated for individuals with cardiac implantable electronic devices (CIEDs) such as pacemakers and implantable ...defibrillators. Magnetic resonance scanners produce magnetic fields that can interact negatively with the metallic components of CIEDs. However, as CIED technology has advanced, newer MRI conditional devices have been developed that are now in clinical use and these systems have had demonstrated safety in the MRI environment. Despite the supportive data of such CIED systems, physicians remain reluctant to perform MRI scanning of conditional devices. This joint statement by the Canadian Heart Rhythm Society and the Canadian Association of Radiologists describes a collaborative process by which CIED specialists and clinics can work with radiology departments and specialists to safely perform MRI in patients with MRI conditional CIED systems. The steps required for patient and scanning preparation and the roles and responsibilities of the CIED and radiology departments are outlined. We also briefly outline the risks and a process by which patients with nonconditional CIEDs might also receive MRI in highly specialized centres. This document supports MRI in patients with MRI conditional CIEDs and offers recommendations on how this can be implemented safely and effectively.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The Medtronic Sprint Fidelis family of leads has recently been the subject of a widespread advisory. Lead failure rates are estimated at 2.3% at 30 months, 2.6 times the failure rate of the reference ...Medtronic 6947 lead.
The purpose of this study was to contact pediatric and adult implantable cardioverter-defibrillator (ICD) implant centers across Canada to determine the short-term response to the October 15, 2007 Medtronic Fidelis lead advisory.
All centers completed an 11-part survey to assess the frequency and presentation of lead failure, operator characteristics, and center's response.
Lead failure was noted in 80 (1.29%) of 6,181 patients at 21.0 months, with inappropriate shocks experienced in 45 (56%) of the 80 patients (overall risk 0.73%). No deaths were attributed to lead failure. Sensing was the primary form of failure, seen in 60 leads (75%), with pacing failure in 10 (13%), and high-voltage failure in 15 (19%). Assessment of the previous routine ICD interrogation prior to the advisory or lead failure demonstrated evidence of altered lead performance in only 8 (10%) of the 80 leads. Inappropriate shocks typically were multiple (median 7, range 1-122), with a single shock seen in only 5 patients. Lead failure was noted in 18 of 23 centers, representing 89.8% of leads implanted, with at least one failure noted in 15 of 16 centers that implanted more than 200 leads. Forty-seven of the 135 operators in the 23 institutions implanted the 80 leads that subsequently failed. Only 16 operators were involved in more than a single lead that subsequently failed; seven operators participated in three or more leads that subsequently failed. Seven centers planned to replace leads in most pacing-dependent patients, and two centers planned to replace leads in patients unable to hear the alert tone.
This national experience suggests a Fidelis lead failure rate of 1.29% at 21 months, most often presenting with multiple inappropriate shocks without evidence of impending failure from routine lead follow-up. Lead failure did not appear to cluster around specific operators or around high-volume or low-volume implant centers.
Abstract Background Anticoagulation in patients undergoing atrial fibrillation (AF) ablation is crucial to minimize the risk of thromboembolic complications. There are broad ranges of approaches to ...anticoagulation management pre and post AF ablation procedures. The purpose of this study was to determine the anticoagulation strategies currently in use in patients peri- and post AF ablation in Canada. Methods A Web-based national survey of electrophysiologists performing AF ablation in Canada collected data regarding anticoagulation practice prior to ablation, periprocedural bridging, and duration of postablation anticoagulation. Results The survey was completed by 36 (97%) of the 37 electrophysiologists performing AF ablation across Canada. Prior to AF ablation, 58% of electrophysiologists started anticoagulation for patients with paroxysmal AF CHADS2 scores of 0 to 1, 92% for paroxysmal AF CHADS2 scores ≥ 2, 83% for persistent AF CHADS2 scores of 0 to 1, and 97% for persistent AF CHADS2 scores ≥ 2. For patients with CHADS2 0 to 1, warfarin was continued for at least 3 months by most physicians (89% for paroxysmal and 94% for persistent AF). For patients with CHADS2 ≥ 2 and with no recurrence of AF at 1 year post ablation, 89% of physicians continued warfarin. Conclusions Although guidelines recommend long-term anticoagulation in patients with CHADS2 ≥ 2, 11% of physicians would discontinue warfarin in patients with no evidence of recurrent AF 1 year post successful ablation. Significant heterogeneity exists regarding periprocedural anticoagulation management in clinical practice. Clinical trial evidence is required to guide optimal periprocedural anticoagulation and therapeutic decisions regarding long-term anticoagulation after an apparently successful catheter ablation for AF.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract Remote monitoring (RM) is a form of telemedicine technology that permits implanted pacemakers and implantable cardioverter-defibrillators to transmit diagnostic information for review by ...health care professionals without patients needing to visit the device follow-up clinic. A bedside transmitter in the patient's home conveys the device data using standard telecommunication protocol to a protected internet-accessible RM data server, which authorized health care professionals can access at any time using standard web browser software. Evidence indicates it can accelerate identification of clinical events and potential device problems. RM raises important medicolegal issues concerning the protection of a patient's rights and the safeguarding of patient health information related to the collection, storage, and use of patient device information that must be addressed by follow-up centres. This position statement recommends that remote monitoring be available at all device follow-up clinics as an integral part of the standard of care of device patients and also provides helpful advice to centres for the proper design, implementation, and integration of a remote monitoring system into the clinic.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Abstract In 2010, the Canadian Cardiovascular Society embarked on an initiative to develop pan-Canadian quality indicators (QIs) and standardized data definitions with the ultimate goal of ...monitoring, comparing, and contrasting national cardiovascular care and its outcomes. One of the first working groups to be established was tasked with identifying and then defining a set of QIs for atrial fibrillation/flutter (AF/AFL). The Canadian Cardiovascular Society “Best Practices for Developing Cardiovascular Quality Indicators” methodology was used to develop an initial catalogue of 25 QIs intended to measure critical issues around access, process, and outcomes relating to AF/AFL management. This list was subsequently pared down to 5 QIs felt to have the greatest relative importance for quality assurance and measurability so as to facilitate early adoption. Three of these QIs were finally selected to assess the feasibility of their measurement using existing administrative datasets. These were the number of patients with a diagnosis of nonvalvular AF/AFL at high risk of stroke (75 years or older, or CHADS2 ≥ 2) receiving an oral anticoagulant, and the rates of stroke and major haemorrhage in patients with nonvalvular AF/AFL according to CHA2 DS2 -VASc score and anticoagulant use. Despite their clear importance in assessing AF/AFL care, none of these 3 QIs were found to be readily measurable across Canada using existing national datasets. Investment in new medical data infrastructure is required to facilitate regular monitoring of QIs to improve cardiovascular care.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Ablation of left ventricular tachycardia (LV VT) involves point-by-point reconstruction of the three-dimensional (3D) virtual anatomy. It is time consuming and requires substantial fluoroscopy ...exposure. Two-dimensional (2D) intracardiac echocardiography (ICE) affords real-time imaging of the cardiac structures.
This study sought to evaluate a mapping system integrating ICE with 3D mapping to guide VT ablation.
Seventeen patients (16 men, 62 +/- 11 years, LV ejection fraction 40% +/- 15%) had ablation of nonidiopathic VT guided using a system integrating 3D mapping and ICE. ICE probe with a location sensor tracked by the mapping system was positioned in the right heart. Endocardial contours traced on gated images of the LV were used to generate a registered 3D map. Regional wall motion abnormalities (WMA) were tagged.
3D maps were created in 26 +/- 8 min, before entering the LV and without fluoroscopy. Maps were built from 23 +/- 7 contours. Regional WMA corresponded to low bipolar voltage (<0.5 mV). Procedure time was 240 +/- 77 min, with fluoroscopy time of 25 +/- 12 min. LV volume by ICE was 172 +/- 119 cm(3) versus 164 +/- 112 cm(3) for the point-by-point maps (P = .5). Scar area by ICE was 33 +/- 32 cm(2) versus 36 +/- 33 cm(2) for voltage mapping (P = .4). At 5 +/- 4 months, 12 patients (71%) were free of VT.
A system combining 2D ICE and 3D mapping can reconstruct a 3D shell of the LV, including a substrate map based on regional WMA without the need to enter the LV. VT ablation guided using this approach is safe and effective.
Whether statins reliably reduce the risk of postoperative atrial fibrillation (POAF) in patients undergoing cardiac surgery remains controversial. We sought to determine the impact of statin use on ...new-onset postdischarge POAF in the Post-Surgical Enhanced Monitoring for Cardiac Arrhythmias and Atrial Fibrillation (SEARCH-AF) CardioLink-1 randomized controlled trial.
We randomized 336 patients with risk factors for stroke (CHA2DS2-VASc score ≥ 2) and no history of preoperative atrial fibrillation (AF) to 30-day continuous cardiac rhythm monitoring after discharge from cardiac surgery with a wearable, patched-based device or to usual care. The primary endpoint was the occurrence of cumulative AF and/or atrial flutter lasting for ≥ 6 minutes detected by continuous monitoring, or AF and/or atrial flutter documented by a 12-lead electrocardiogram within 30 days of randomization.
The 260 patients (77.4%) discharged on statins were more likely to be male (P = 0.018) and to have lower CHA2DS2-VASc scores (P = 0.011). Patients treated with statins at discharge had a 2-fold lower rate of POAF than those who were not treated with statins in the entire cohort (18.4% vs 8.1%, log-rank P = 0.0076). On multivariable Cox regression including the CHA2DS2-VASc score adjustment, statin use was associated with a lower risk of POAF (hazard ratio 0.43, 95% confidence interval: 0.25-0.98, P = 0.043). Use of statins at a higher intensity was associated with lower risk of POAF, suggestive of a dose–response effect (log-rank Ptrend = 0.0082).
The use of statins was associated with a reduction in postdischarge POAF risk among patients undergoing cardiac surgery. The routine use of high-intensity statin to prevent subacute POAF after discharge deserves further study.
L’efficacité des statines dans la réduction du risque de fibrillation auriculaire postopératoire (FAPO) chez les patients ayant subi une chirurgie cardiaque ne fait pas l’unanimité. Nous avons tenté de déterminer l’effet de l’utilisation des statines sur la survenue d’une FAPO inaugurale consécutive au congé de l’hôpital dans l’essai SEARCH-AF CardioLink-1, un essai contrôlé à répartition aléatoire sur le suivi étroit en postopératoire des arythmies cardiaques et de la fibrillation auriculaire.
Nous avons réparti aléatoirement 336 patients présentant des facteurs de risque d’AVC (score CHA2DS2-VASc ≥ 2) sans antécédents de fibrillation auriculaire (FA) préopératoire dans deux groupes : les patients du premier groupe étaient équipés d’un dispositif portable sous forme de timbre pour la surveillance continue du rythme cardiaque pendant 30 jours après la sortie de l’hôpital suivant une chirurgie cardiaque; les patients du second groupe étaient suivis de façon conventionnelle. Le critère d’évaluation principal était la survenue cumulative de FA et/ou de flutter auriculaire durant ≥ 6 minutes détecté par la surveillance continue, ou la FA et/ou le flutter auriculaire confirmé par un électrocardiogramme à 12 dérivations dans les 30 jours suivant la répartition aléatoire.
Les 260 patients (77,4 %) prenant des statines à leur congé de l’hôpital étaient plus susceptibles d’être des hommes (p = 0,018) et d’avoir un score CHA2DS2-VASc plus faible (p = 0,011). Les patients traités par des statines à leur congé de l’hôpital avaient deux fois moins de risques de présenter une FAPO que les patients ne recevant pas de statines dans l’ensemble de la cohorte (18,4 % contre 8,1 %, valeur de p calculée selon le test de Mantel-Haenszel = 0,0076). Dans une régression de Cox multivariable incluant l’ajustement du score CHA2DS2-VASc, l’utilisation des statines a été associée à un risque moindre de FAPO (rapport des risques instantanés : 0,43, intervalle de confiance à 95 % de 0,25 à 0,98; p = 0,043). L’utilisation de statines à plus fortes doses a été associée à un risque moindre de FAPO, ce qui laisse croire à un effet dose-réponse (valeur de p de tendance selon le test de Mantel-Haenszel = 0,0082).
L’utilisation de statines est associée à une réduction du risque de FAPO après le congé de l’hôpital chez les patients ayant subi une chirurgie cardiaque. L’utilisation systématique de statines à fortes doses pour prévenir la FAPO subaiguë après le congé d’hôpital mérite une étude plus approfondie.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Endocardial catheter ablation for ventricular tachycardia (VT) may fail because of the inability to deliver transmural lesions. Ultra-low–temperature cryoablation (ULTC) uses near-critical nitrogen ...and can generate temperatures as low as –196 °C. We report a series of 18 patients who underwent ULTC at the McGill University Health Centre (MUHC), representing the largest single-centre experience to date.
Eighteen patients with monomorphic drug-refractory VT underwent VT ablation with ULTC at our institution as part of the first-in-human CryoCure-VT trial (NCT04893317). After voltage map, the mapping catheter was replaced with the ULTC catheter, and lesions were applied over a fixed duration of time (60-180 seconds), followed by a 60-second thaw and another application at the original duration (freeze-thaw-freeze). Duration of ablation time was selected depending on the wall thickness of the left ventricle monitored with intracardiac echo to achieve tissue depths of 4.5 to 7.5 mm.
Baseline left ventricular ejection fraction was 32%, mean age 71 years, 94% were male. A total of 32 sustained VTs were induced in 16 of 18 patients. A total of 177 cryoablation lesions were delivered (9.8 lesions per patient). Of the 16 patients with inducible VT, 15 (94%) were rendered noninducible postablation, and 1 was inducible only for a nonclinical VT. Complications included 1 pericardial effusion that required drainage. From 18 patients, 16 (89%) were discharged within the first 24 hours postablation.
ULTC is feasible and permits acute control of monomorphic VT during VT ablation procedures in drug-refractory patients.
L’ablation endocardique par cathéter pour traiter la tachycardie ventriculaire (TV) peut être un échec, en raison de l’incapacité à créer des lésions transmurales. La cryoablation à ultra-basse température (ULTC, pour ultra-low-temperature cryoablation) réalisée au moyen d’azote près de son point critique liquide-vapeur peut produire des températures aussi basses que –196 °C. Nous faisons état d’une série de 18 patients ayant subi une ULTC au Centre universitaire de santé McGill (CUSM), ce qui représente la plus importante expérience menée dans un seul établissement jusqu’à ce jour.
Au total, 18 patients atteints de TV monomorphe pharmacorésistante ont subi une ablation de la TV par ULTC à notre établissement, dans le cadre du premier essai mené chez l’humain sur la guérison par cryothérapie de la TV (NCT04893317). Après l’obtention de la carte électrophysiologique, le cathéter de cartographie a été remplacé par le cathéter d’ULTC, qui a permis de créer des lésions par l’application de froid pendant une durée fixe (de 60 à 180 secondes), suivie d’une période de dégel de 60 secondes, puis d’une autre application de froid pendant la même durée que la première application (cycle gel-dégel-gel). La durée de l’ablation a été déterminée en fonction de l’épaisseur de la paroi du ventricule gauche surveillée par échocardiographie endocavitaire afin d’obtenir des profondeurs tissulaires de 4,5 à 7,5 mm.
La fraction d’éjection du ventricule gauche initiale était de 32 %, l’âge moyen des sujets était de 71 ans et 94 % d’entre eux étaient de sexe masculin. Au total, 32 TV soutenues ont été induites chez 16 patients sur 18. Dans l’ensemble, 177 lésions de cryoablation ont été créées (soit 9,8 lésions par patient). Après l’ablation, nous avons été incapables d’induire une TV chez 15 (94 %) des 16 patients chez qui nous en avions induit avant l’intervention et, chez le patient restant, nous avons pu induire une TV non clinique seulement. Les complications comprenaient un cas d’épanchement péricardique ayant nécessité un drainage. Au total, 16 (89 %) des 18 patients ont reçu leur congé de l’hôpital dans les 24 heures suivant l’ablation.
L’ULTC est réalisable et permet une maîtrise rigoureuse de la TV monomorphe lors des interventions d’ablation de la TV chez les patients dont la TV est pharmacorésistante.
Display omitted
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Atrial fibrillation (AF) ablation guided by complex fractionated electrograms (CFE) has been described, but the spatial and temporal stability of the electrograms (EGMs) has been questioned.
The ...purpose of this study was to prospectively assess the spatial and temporal stability of CFE in patients with persistent AF.
Twenty-four patients were studied. For 12 patients, two high-density CFE maps were performed during AF at baseline (0 minute) and 20 minutes later using the EnSite NavX system. Six-second bipolar EGMs were collected throughout the left atrium (LA) using a circular mapping catheter. Automated software measured the time between discrete local EGM deflections yielding a mean local cycle length (CL). EGMs with mean CL <120 ms were considered CFE. The LA was divided into six regions. Spatial distribution of EGMs at 0 and 20 minutes was compared in each region across three different CL ranges (A = 50-120 ms, B = 121-200 ms, C = 200-500 ms). The 0- and 20-minute CFE maps were directly superimposed offline in MATLAB, and the mean CL value for each point that was sampled in both maps was compared in each CL range (A-C). For the other 12 patients, repetitive measurements (1-minute intervals for 5 minutes) of mean CL were obtained at a sample point for each CL range (A-C) in each patient and compared for consistency.
A total of 324 +/- 65 points were collected per map. Globally in the LA, the distribution of CLs did not change from 0 to 20 minutes (A: 47.1% vs 45.0%; B: 35.3% vs 36.5%; C: 16.0% vs 16.9%; P = .6). The CL distribution in each of the six regions of the LA also did not change significantly from 0 to 20 minutes. There was no significant change in repetitive CL measures for range A (mean DeltaCL 12 +/- 4 ms, P = .4). However, there was significant variation over 5 minutes for ranges B and C (mean DeltaCL 39 +/- 19 ms and 48 +/- 22 ms, respectively, P <.05 for both). Superimposing maps showed 74.7% point-to-point match for range A, 39.3% for range B, and 14.2% for range C (within 30 ms), with a significant correlation seen only for range A (r = 0.82, P <.001).
CFE show a high degree of spatial and temporal stability. Greater temporal variation is seen in progressively longer CL regions that are outside of the CFE region of interest.
