Adherent skin barrier drape use is associated with a reduced risk of cardiac implantable device infection: Results from a prospective study of 14,225 procedures.

Background: Cardiac implantable electronic device (CIED) infection is a costly and highly morbid complication. Perioperative interventions, including the use of antibiotic pouches and intensified perioperative antibiotic regimens, have demonstrated marginal efficacy at reducing CIED infection. Additional research is needed to identify additional interventions to reduce infection risk. Objective: We sought to evaluate whether adherent skin barrier drape use is associated with a reduction in CIED infection. Methods: A prospective registry of all CIED implantation procedures was established at our institution in January 2007. The registry was established in collaboration with our hospital infection prevention team with a specific focus on prospectively identifying all potential CIED infections. All potential CIED infections were independently adjudicated by 2 physicians blinded to the use of an adherent skin barrier drape. Results: Over a 13-year period, 14,225 procedures were completed (mean age 72 ± 14 years; female 4,918 (35%); new implants 10,005 (70%); pulse generator changes 2585 (18%); upgrades 1635 (11%). Of those, 2469 procedures (17.4%) were performed using an adherent skin barrier drape. There were 103 adjudicated device infections (0.73%). The infection rate in patients in the barrier use groups was 8 of 2469 (0.32%) as compared with 95 of 11,756 (0.8%) in the nonuse group (P = .0084). In multivariable analysis, the use of an adherent skin barrier drape was independently associated with a reduction in infection (odds ratio 0.32; 95% confidence interval 0.154-0.665; P = .002). Conclusion: The use of an adherent skin barrier drape at the time of cardiac device surgery is associated with a lower risk of subsequent infection.

The Prevalence and Characteristics of Arrhythmic Mitral Valve Prolapse in Patients With Unexplained Cardiac Arrest.

BACKGROUND: There is growing evidence that mitral valve prolapse (MVP) is associated with otherwise unexplained cardiac arrest (UCA). However, reports are hindered by the absence of a systematic ascertainment of alternative diagnoses. OBJECTIVES: This study reports the prevalence and characteristics of MVP in a large cohort of patients with UCA. METHODS: Patients were enrolled following an UCA, defined as cardiac arrest with no coronary artery disease, preserved left ventricular ejection fraction, and no apparent explanation on electrocardiogram. A comprehensive evaluation was performed, and patients were diagnosed with idiopathic ventricular fibrillation (IVF) if no cause was found. Echocardiography reports were reviewed for MVP. Patients with MVP were divided into 2 groups: those with IVF (AMVP) and those with an alternative diagnosis (nonarrhythmic MVP). Patient characteristics were then compared. The long-term outcomes of AMVP were reported. RESULTS: Among 571 with an initially UCA, 34 patients had MVP (6%). The prevalence of definite MVP was significantly higher in patients with IVF than those with an alternative diagnosis (24 of 366 [6.6%] vs 5 of 205 [2.4%]; P = 0.03). Bileaflet prolapse was significantly associated with AMVP (18 of 23 [78%] vs 1 of 8 [12.5%]; P = 0.001; OR: 25.2). The proportion of patients with AMVP who received appropriate implantable cardioverter-defibrillator therapies over a median follow-up of 42 months was 21.1% (4 of 19). CONCLUSIONS: MVP is associated with otherwise UCA (IVF), with a prevalence of 6.6%. Bileaflet prolapse appears to be a feature of AMVP, although future studies need to ascertain its independent association. A significant proportion of patients with AMVP received appropriate implantable cardioverter-defibrillator therapies during follow-up.

The 2023 Canadian Cardiovascular Society Clinical Practice Update on Management of the Patient With a Prolonged QT Interval.

A prolonged QT interval on the electrocardiogram is associated with an increased risk of the torsades de pointes form of ventricular arrhythmia resulting in syncope, sudden cardiac arrest or death, or misdiagnosis as a seizure disorder. The cause of QT prolongation can be congenital and inherited as an autosomal dominant variant, or it can be transient and acquired, often because of QT-prolonging drugs or electrolyte abnormalities. Automated measurement of the QT interval can be inaccurate, especially when the baseline electrocardiogram is abnormal, and manual verification is recommended. In this clinical practice update we provide practical tips about measurement of the QT interval, diagnosis, and management of congenital long QT syndrome and acquired prolongation of the QT interval. For congenital long QT syndrome, certain ß-adrenergic-blocking drugs are highly effective, and implantable defibrillators are infrequently required. Many commonly prescribed drugs such as antidepressants and antibiotics can prolong the QT interval, and recommendations are provided on their safe use.

Management of Inherited Arrhythmia Syndromes: A HiRO Consensus Handbook on Process of Care.

Inherited arrhythmia syndromes are rare genetic conditions that predispose seemingly healthy individuals to sudden cardiac arrest and death. The Hearts in Rhythm Organization is a multidisciplinary Canadian network of clinicians, researchers, patients, and families that aims to improve care for patients and families with inherited cardiac conditions, focused on those that confer predisposition to arrhythmia and sudden cardiac arrest and/or death. The field is rapidly evolving as research discoveries increase. A streamlined, practical guide for providers to diagnose and follow pediatric and adult patients with inherited cardiac conditions represents a useful tool to improve health system utilization, clinical management, and research related to these conditions. This review provides consensus care pathways for 7 conditions, including the 4 most common inherited cardiac conditions that confer predisposition to arrhythmia, with scenarios to guide investigation, diagnosis, risk stratification, and management. These conditions include Brugada syndrome, long QT syndrome, arrhythmogenic right ventricular cardiomyopathy and related arrhythmogenic cardiomyopathies, and catecholaminergic polymorphic ventricular tachycardia. In addition, an approach to investigating and managing sudden cardiac arrest, sudden unexpected death, and first-degree family members of affected individuals is provided. Referral to specialized cardiogenetic clinics should be considered in most cases. The intention of this review is to offer a framework for the process of care that is useful for both experts and nonexperts, and related allied disciplines such as hospital management, diagnostic services, coroners, and pathologists, in order to provide high-quality, multidisciplinary, standardized care.

Les syndromes d'arythmie héréditaires sont des troubles génétiques rares qui prédisposent des personnes en apparence en bonne santé à un arrêt cardiaque soudain et à la mort. L'organisation Hearts in Rhythm Organization est un réseau multidisciplinaire canadien qui regroupe des cliniciens, des chercheurs ainsi que des patients et leurs proches dans le but d'améliorer les soins prodigués aux patients atteints de maladies cardiaques héréditaires et à leur famille, en particulier dans le cas des maladies qui entraînent une prédisposition à l'arythmie et à un arrêt cardiaque soudain et/ou à la mort. Puisque ce champ de recherche évolue rapidement, la mise au point d'un guide pratique et simple à l'intention des professionnels de la santé pour le diagnostic et le suivi des patients enfants et adultes présentant une maladie cardiaque héréditaire serait donc un outil intéressant pour améliorer l'utilisation du système de santé et la prise en charge clinique de ces maladies tout en orientant la recherche à ce propos. La présente synthèse expose les trajectoires de soins faisant l'objet d'un consensus pour sept maladies, dont les quatre maladies cardiaques héréditaires les plus courantes qui prédisposent à l'arythmie. Elle présente aussi des scénarios pour orienter les examens, le diagnostic, la stratification du risque et la prise en charge des patients. Ces maladies sont le syndrome de Brugada, le syndrome du QT long, la cardiomyopathie arythmogénique du ventricule droit et les cardiomyopathies arythmogènes associées, et la tachycardie ventriculaire polymorphe catécholaminergique. En outre, une approche pour la prise en charge de l'arrêt cardiaque soudain, de mort subite inattendue et des membres de la famille immédiate de la personne touchée est proposée. L'orientation vers des cliniques spécialisées en cardiogénétique doit être envisagée dans la plupart des cas. L'objectif est d'établir un cadre de soins qui soit utile pour les experts et les non-experts ainsi que pour les professionnels des domaines connexes, par exemple le personnel de l'administration hospitalière et des services diagnostiques, les coroners et les pathologistes, en vue d'offrir des soins multidisciplinaires normalisés de grande qualité.

Standard vs Augmented Ablation of Paroxysmal Atrial Fibrillation for Reduction of Atrial Fibrillation Recurrence: The AWARE Randomized Clinical Trial.

Importance: Recurrent atrial fibrillation (AF) commonly occurs after catheter ablation and is associated with patient morbidity and health care costs. Objective: To evaluate the superiority of an augmented double wide-area circumferential ablation (WACA) compared with a standard single WACA in preventing recurrent atrial arrhythmias (AA) (atrial tachycardia, atrial flutter, or atrial fibrillation [AF]) in patients with paroxysmal AF. Design, Setting, and Participants: This was a pragmatic, multicenter, prospective, randomized, open, blinded end point superiority clinical trial conducted at 10 university-affiliated centers in Canada. The trial enrolled patients 18 years and older with symptomatic paroxysmal AF from March 2015 to May 2017. Analysis took place between January and April 2022. Analyses were intention to treat. Interventions: Patients were randomized (1:1) to receive radiofrequency catheter ablation for pulmonary vein isolation with either a standard single WACA or an augmented double WACA. Main Outcomes and Measures: The primary outcome was AA recurrence between 91 and 365 days postablation. Patients underwent 42 days of ambulatory electrocardiography monitoring after ablation. Secondary outcomes included need for repeated catheter ablation and procedural and safety variables. Results: Of 398 patients, 195 were randomized to the single WACA (control) arm (mean [SD] age, 60.6 [9.3] years; 65 [33.3%] female) and 203 to the double WACA (experimental) arm (mean [SD] age, 61.5 [9.3] years; 66 [32.5%] female). Overall, 52 patients (26.7%) in the single WACA arm and 50 patients (24.6%) in the double WACA arm had recurrent AA at 1 year (relative risk, 0.92; 95% CI, 0.66-1.29; P = .64). Twenty patients (10.3%) in the single WACA arm and 15 patients (7.4%) in the double WACA arm underwent repeated catheter ablation (relative risk, 0.72; 95% CI, 0.38-1.36). Adjudicated serious adverse events occurred in 13 patients (6.7%) in the single WACA arm and 14 patients (6.9%) in the double WACA arm. Conclusions and Relevance: In this randomized clinical trial of patients with paroxysmal AF, additional ablation by performing a double ablation lesion set did not result in improved freedom from recurrent AA compared with a standard single ablation set. Trial Registration: ClinicalTrials.gov Identifier: NCT02150902.

Diagnosis and management of patients who present with narrow complex tachycardia in the emergency department.

INTRODUCTION: While narrow complex tachycardia (NCT) is a common presentation to the emergency department (ED), little is known about its incidence in the ED or about emergency physician expertise in its diagnosis and management. We sought to compare cases of NCT due to primary arrhythmias to those with a rapid heart rate secondary to a medical issue, as well as to determine the accuracy of ED physician diagnosis and appropriateness of treatment. METHODS: We conducted a health records review at a large academic hospital ED staffed by 95 physicians and included consecutive adult patients over 7 months (2020-2021) with NCT (heart rate ≥ 130 bpm and QRS < 120 ms). Cases were reviewed for accuracy of ECG diagnosis and for correctness of treatment as per guidelines by an adjudication committee. RESULTS: We identified 310 ED visits (0.8% of all ED visits), mean age 65.1 years, 52.6% female. Primary arrhythmias accounted for 54.8%. ED physicians correctly interpreted 86.6% of ECGs. The most common arrhythmias and accuracy of ED physician ECG interpretation were atrial fibrillation 44.5% (95.1%), sinus tachycardia 24.2% (90.5%), atrial flutter 15.8% (61.5%), and supraventricular tachycardia (SVT) 12.9% (81.6%). Treatments were judged optimal in 96.5% of primary NCT and 99.3% in secondary NCT. Treatments were suboptimal for failure to reduce heart rate < 100 bpm prior to discharge in 2.1% of primary cases and failure to treat underlying cause in 0.7% of secondary cases. CONCLUSION: NCT was found in 0.8% of all ED visits, with more being primary NCT. ED physicians correctly interpreted 86.6% of ECGs but had difficulty differentiating atrial flutter and SVT. They implemented appropriate care in most cases but sometimes failed to adequately control heart rate or to treat the underlying condition, suggesting opportunities to improve care of NCT in the ED.

RéSUMé: INTRODUCTION: Bien que la tachycardie à complexe QRS étroite (narrow complex tachycardia [NCT]) soit une présentation courante au service des urgences (SU), on sait peu de choses sur son incidence dans le SU ou sur l'expertise des médecins urgentistes dans son diagnostic et sa prise en charge. Nous avons cherché à comparer les cas de NCT dus à des arythmies primaires à ceux avec une fréquence cardiaque rapide secondaire à un problème médical, ainsi que pour déterminer l'exactitude du diagnostic de médecin ED et la pertinence du traitement. MéTHODES: Nous avons effectué un examen des dossiers médicaux dans les urgences d'un grand hôpital universitaire où travaillent 95 médecins et avons inclus des patients adultes consécutifs sur 7 mois (2020-2021) présentant une NCT (fréquence cardiaque ≥ 130 bpm et QRS < 120 ms). Les cas ont été examinés par un comité d'adjudication pour vérifier l'exactitude du diagnostic ECG et la justesse du traitement conformément aux directives. RéSULTATS: Nous avons recensé 310 visites aux urgences (0,8 % de toutes les visites aux urgences), l'âge moyen étant de 65,1 ans, 52,6 % de femmes. Les arythmies primaires représentaient 54,8 %. Les médecins urgentistes ont correctement interprété 86,6 % des ECG. Les arythmies les plus fréquentes et la précision de l'interprétation de l'ECG par le médecin de l'urgence étaient la fibrillation auriculaire 44,5 % (95,1 %), la tachycardie sinusale 24,2 % (90,5 %), le flutter auriculaire 15,8 % (61,5 %) et la tachycardie supraventriculaire (TSV) 12,9 % (81,6 %). Les traitements ont été jugés optimaux dans 96,5 % des NCT primaires et 99,3 % des NCT secondaires. Les traitements étaient sous-optimaux en raison de l'incapacité à réduire la fréquence cardiaque < 100 bpm avant la sortie de l'hôpital dans 2,1 % des cas primaires et de l'incapacité à traiter la cause sous-jacente dans 0,7 % des cas secondaires. CONCLUSION: Une NCT a été constatée dans 0,8 % de toutes les visites aux urgences, la plupart étant des NCT primaires. Les médecins des services d'urgence ont interprété correctement 86,6 % des ECG mais ont eu des difficultés à différencier le flutter auriculaire et la TSV. Ils ont mis en œuvre des soins appropriés dans la plupart des cas, mais n'ont parfois pas réussi à contrôler adéquatement la fréquence cardiaque ou à traiter l'affection sous-jacente, ce qui laisse entrevoir des possibilités d'améliorer la prise en charge des NCT aux urgences.

Identification and in-silico characterization of splice-site variants from a large cardiogenetic national registry.

Splice-site variants in cardiac genes may predispose carriers to potentially lethal arrhythmias. To investigate, we screened 1315 probands and first-degree relatives enrolled in the Canadian Hearts in Rhythm Organization (HiRO) registry. 10% (134/1315) of patients in the HiRO registry carry variants within 10 base-pairs of the intron-exon boundary with 78% (104/134) otherwise genotype negative. These 134 probands were carriers of 57 unique variants. For each variant, American College of Medical Genetics and Genomics (ACMG) classification was revisited based on consensus between nine in silico tools. Due in part to the in silico algorithms, seven variants were reclassified from the original report, with the majority (6/7) downgraded. Our analyses predicted 53% (30/57) of variants to be likely/pathogenic. For the 57 variants, an average of 9 tools were able to score variants within splice sites, while 6.5 tools responded for variants outside these sites. With likely/pathogenic classification considered a positive outcome, the ACMG classification was used to calculate sensitivity/specificity of each tool. Among these, Combined Annotation Dependent Depletion (CADD) had good sensitivity (93%) and the highest response rate (131/134, 98%), dbscSNV was also sensitive (97%), and SpliceAI was the most specific (64%) tool. Splice variants remain an important consideration in gene elusive inherited arrhythmia syndromes. Screening for intronic variants, even when restricted to the ±10 positions as performed here may improve genetic testing yield. We compare 9 freely available in silico tools and provide recommendations regarding their predictive capabilities. Moreover, we highlight several novel cardiomyopathy-associated variants which merit further study.

Sex Differences and Utility of Treadmill Testing in Long-QT Syndrome.

Background Diagnosis of congenital long-QT syndrome (LQTS) is complicated by phenotypic ambiguity, with a frequent normal-to-borderline resting QT interval. A 3-step algorithm based on exercise response of the corrected QT interval (QTc) was previously developed to diagnose patients with LQTS and predict subtype. This study evaluated the 3-step algorithm in a population that is more representative of the general population with LQTS with milder phenotypes and establishes sex-specific cutoffs beyond the resting QTc. Methods and Results We identified 208 LQTS likely pathogenic or pathogenic KCNQ1 or KCNH2 variant carriers in the Canadian NLQTS (National Long-QT Syndrome) Registry and 215 unaffected controls from the HiRO (Hearts in Rhythm Organization) Registry. Exercise treadmill tests were analyzed across the 5 stages of the Bruce protocol. The predictive value of exercise ECG characteristics was analyzed using receiver operating characteristic curve analysis to identify optimal cutoff values. A total of 78% of male carriers and 74% of female carriers had a resting QTc value in the normal-to-borderline range. The 4-minute recovery QTc demonstrated the best predictive value for carrier status in both sexes, with better LQTS ascertainment in female patients (area under the curve, 0.90 versus 0.82), with greater sensitivity and specificity. The optimal cutoff value for the 4-minute recovery period was 440 milliseconds for male patients and 450 milliseconds for female patients. The 1-minute recovery QTc had the best predictive value in female patients for differentiating LQTS1 versus LQTS2 (area under the curve, 0.82), and the peak exercise QTc had a marginally better predictive value in male patients for subtype with (area under the curve, 0.71). The optimal cutoff value for the 1-minute recovery period was 435 milliseconds for male patients and 455 milliseconds for femal patients. Conclusions The 3-step QT exercise algorithm is a valid tool for the diagnosis of LQTS in a general population with more frequent ambiguity in phenotype. The algorithm is a simple and reliable method for the identification and prediction of the 2 major genotypes of LQTS.

Should they stay, or should they go: Do we need to remove the old cardiac implantable electronic device if a new system is required on the contralateral side?

Background: Ipsilateral approach in patients requiring cardiac implantable electronic device (CIED) revision or upgrade may not be feasible, primarily due to vascular occlusion. If a new CIED is implanted on the contralateral side, a common practice is to explant the old CIED to avoid device interaction. Objective: The purpose of this study was to assess a conservative approach of abandoning the old CIED after implanting a new contralateral device. Methods: We used an artificial intelligence algorithm to analyze postimplant chest radiographs to identify those with multiple CIEDs. Outcomes of interest included device interaction, abandoned CIED elective replacement indicator (ERI) behavior, subsequent programming changes, and explant of abandoned CIED. Theoretical risk of infection with removal of abandoned CIED was estimated using a validated scoring system. Results: Among 12,045 patients, we identified 40 patients with multiple CIEDs. Occluded veins were the most common indication for contralateral implantation (n = 27 [67.5%]). Fifteen abandoned CIEDs reached ERI, with 4 reverting to VVI 65. One patient underwent explant due to device interaction, and 2 required device reprogramming. Of 32 patients with an implantable cardioverter-defibrillator, 8 (25%) had treated ventricular arrhythmia. There were no failed or inappropriate therapies due to interaction. Eighteen patients (45%) had hypothetical >1% annual risk of hospitalization for device infection if the abandoned CIED had been explanted. Conclusion: In patients requiring new CIED implant on the contralateral side, abandoning the old device is feasible. This approach may reduce the risk of infection and concerns regarding abandoned leads and magnetic resonance imaging scans. Knowledge of ERI behavior is essential to avoid device interactions.

Rhythm-Monitoring Strategy and Arrhythmia Recurrence in Atrial Fibrillation Ablation Trials: A Systematic Review.

Background: : The rhythm-monitoring strategy after catheter ablation (CA) for atrial fibrillation (AF) impacts the detection of atrial arrhythmia recurrence and is not well characterized. We performed a systematic review and meta-regression analysis to determine whether the duration and mode of rhythm monitoring after CA affects detection of atrial arrhythmia recurrence. Methods: Databases were systematically searched for randomized controlled trials of adult patients undergoing first CA for AF from 2007 to 2021. Duration and strategy of rhythm monitoring were extracted. Meta-regression was used to identify any association between duration of monitoring and detection of atrial arrhythmia recurrence. The primary measure of outcome was single-procedure recurrence of atrial arrhythmia. Results: The search strategy yielded 57 trial arms from 56 randomized controlled trials comprising 5322 patients: 36 arms of patients with paroxysmal AF (PAF), and 21 arms of patients with persistent AF (PeAF) or both PAF/PeAF. Intermittent monitoring was associated with detection of significantly less atrial arrhythmia recurrence than continuous monitoring in PAF arms (31.2% vs 46.9%, P = 0.001), but not in PeAF/PAF-PeAF combined arms (43.3% vs 63.6%, P = 0.12). No significant relationship was seen between the duration of intermittent rhythm monitoring and atrial arrhythmia recurrence detection in either the PAF (P = 0.93) or PeAF/PAF-PeAF combined arms (P = 0.20). Conclusions: Continuous rhythm monitoring detected higher atrial arrhythmia recurrence rates, compared to intermittent rhythm monitoring, in patients with PAF. The duration of intermittent monitoring did not show a statistically significant relationship to the yield of arrhythmia detection, in near identical cohorts of trial subjects undergoing similar interventions, with clinical and research implications.

Contexte: La stratégie qui consiste à surveiller le rythme cardiaque après une ablation par cathéter dans le traitement de la fibrillation auriculaire (FA) a un effet sur la détection de récidive de l'arythmie auriculaire, mais elle n'est pas bien définie. Nous avons mené une revue systématique et une méta-régression pour déterminer si le mode employé pour surveiller le rythme après une ablation par cathéter et la durée de cette surveillance ont un effet sur la détection de récidive de l'arythmie auriculaire. Méthodologie: Des bases de données ont été systématiquement épluchées à la recherche d'essais contrôlés randomisés menés auprès d'adultes subissant leur première ablation par cathéter pour une FA entre 2007 et 2021. La durée et la stratégie utilisées dans la surveillance du rythme ont été recensées. La méta-régression a été utilisée pour déceler tout lien entre la durée de la surveillance et la détection d'une récidive de l'arythmie auriculaire. Le paramètre d'évaluation principal était la récidive de l'arythmie auriculaire avec une seule intervention. Résultats: La stratégie de recherche a fait ressortir 57 groupes de 56 essais contrôlés randomisés comprenant 5 322 patients : 36 groupes de patients présentant une FA paroxystique et 21 groupes de patients présentant une FA persistante ou ces deux types de FA (paroxystique et persistante). La surveillance intermittente a été associée à une moins grande détection de cas d'arythmie auriculaire récidivante, comparativement à la surveillance constante (31,2 % vs 46,9 %, p = 0,001), ce qui n'a pas été le cas dans les groupes où les types de FA (persistante ou paroxystique et persistante) étaient combinés (43,3 % vs 63,6 %, p = 0,12). Aucun lien notable n'a été observé entre la durée de la surveillance intermittente du rythme et la détection de l'arythmie auriculaire récidivante dans le groupe FA paroxystique (p = 0,93) ou dans le groupe des types de FA combinés (p = 0,20). Conclusions: Le taux de détection de l'arythmie auriculaire récidivante était plus élevé avec la surveillance constante qu'avec la surveillance intermittente chez les patients atteints de FA paroxystique. La durée de la surveillance intermittente n'a pas eu de lien statistiquement significatif avec le rendement de détection de l'arythmie, dans des cohortes presque identiques de participants aux essais subissant des interventions similaires, comportant des implications cliniques ou expérimentales.

Outcomes of a comprehensive strategy during repeat atrial fibrillation ablation.

BACKGROUND/PURPOSE: Atrial fibrillation (AF) recurs post-ablation in 30-40% of patients. The approach to a repeat ablation, beyond isolation of reconnected pulmonary veins (PVs), is not well established. We sought to prospectively assess outcomes and predictors of recurrence among consecutive patients who underwent repeat AF ablation with a standardized approach. METHODS: This was a single-center prospective study of consecutive patients who underwent repeat AF ablation. Our protocol consisted of six steps: PV re-isolation, ablation of left atrial low-voltage areas (LVAs), ablation of isoproterenol-induced non-PV triggers, electrophysiology study (EPS) and ablation of induced AVNRT/AVRT, ablation of induced clinical atrial flutters, and lastly empiric ablation as per operator discretion if no other ablation was performed. RESULTS: Among 725 AF ablations performed during the study period, 74 were repeat ablations. Of those undergoing repeat ablation, 53 (72%) had PV reconnection, 30 (41%) had LVAs, seven (10%) had non-PV triggers, five (7%) had AVNRT, and 15 (20%) had typical atrial flutter. Following repeat ablation, arrhythmia-free survival was 65% at 1 year. The absence of PV reconnection was the only factor independently associated with recurrence after repeat ablation (recurrence rate 71%, adjusted OR 7.91, 95% CI 2.31-27.16, p = 0.001). CONCLUSIONS: A comprehensive approach to repeat AF ablation including PV re-isolation, LVA ablation, non-PV trigger ablation, EPS, and flutter ablation was associated with a 65% 1-year arrhythmia-free survival. The absence of PV reconnection was the only independent predictor of arrhythmia recurrence. Further research is needed to identify therapies beyond PV isolation for patients undergoing repeat ablation.

Importance of genetic testing in unexplained cardiac arrest.

AIMS: Genetic testing is recommended in specific inherited heart diseases but its role remains unclear and it is not currently recommended in unexplained cardiac arrest (UCA). We sought to assess the yield and clinical utility of genetic testing in UCA using whole-exome sequencing (WES). METHODS AND RESULTS: Survivors of UCA requiring external defibrillation were included from the Cardiac Arrest Survivor with Preserved Ejection fraction Registry. Whole-exome sequencing was performed, followed by assessment of rare variants in previously reported cardiovascular disease genes. A total of 228 UCA survivors (mean age at arrest 39 ± 13 years) were included. The majority were males (66%) and of European ancestry (81%). Following advanced clinical testing at baseline, the likely aetiology of cardiac arrest was determined in 21/228 (9%) cases. Whole-exome sequencing identified a pathogenic or likely pathogenic (P/LP) variant in 23/228 (10%) of UCA survivors overall, increasing the proportion of 'explained' cases from 9% only following phenotyping to 18% when combining phenotyping with WES. Notably, 13 (57%) of the 23 P/LP variants identified were located in genes associated with cardiomyopathy, in the absence of a diagnosis of cardiomyopathy at the time of arrest. CONCLUSIONS: Genetic testing identifies a disease-causing variant in 10% of apparent UCA survivors. The majority of disease-causing variants was located in cardiomyopathy-associated genes, highlighting the arrhythmogenic potential of such variants in the absence of an overt cardiomyopathy diagnosis. The present study supports the use of genetic testing including assessment of arrhythmia and cardiomyopathy genes in survivors of UCA.

Diagnosis and management of wide complex tachycardia in the emergency department.

INTRODUCTION: While wide complex tachycardia (WCT) is potentially lethal, little is known about its incidence in the ED or about expertise of ED physicians in diagnosing and treating it. We sought to compare WCT ED cases that were primary arrhythmias versus those with rapid heart rate secondary to medical issues, as well as the accuracy of ED diagnosis and appropriateness of treatment. METHODS: We conducted a health records review at a large academic hospital ED staffed by 95 physicians and included consecutive patients over 28 months (2018-2020) with WCT (heart rate ≥ 120 bpm and QRS ≥ 120 ms). Cases were adjudicated for the accuracy of ECG diagnosis versus the cardiology read and for correctness of treatment as per guidelines by two ED physicians and one cardiologist. RESULTS: We identified 306 eligible cases (0.2% of all ED visits): mean age 73.9 years, male 66.0%, admitted 53.3%, died in ED 2.3%. Primary arrhythmias and secondary tachycardias were each 50.0% (95% CI 44.4-55.6%). ED physicians correctly interpreted 81.2% of ECGs. The most common presenting arrythmias and % correct were: atrial fibrillation 42.7% (95.0%), atrial flutter 22.2% (63.5%), sinus tachycardia 12.0% (78.6%), and supraventricular tachycardia (SVT) 11.1% (68.0%). Treatments were judged optimal in 84.3% of primary WCT and 86.9% in secondary WCT. Treatments were suboptimal for: inappropriate drug (3.9% for primary versus 1.3% for secondary), failure to reduce heart rate < 100 prior to discharge home (9.1% for primary versus 34.4% for secondary), and not treating the underlying cause in 5.9% of secondary WCT. CONCLUSIONS: WCT cases were evenly split between primary arrhythmias and secondary cases. ED physicians interpreted the ECG correctly in 81% but over-called atrial flutter and SVT. They implemented appropriate care in most cases but sometimes failed to adequately control heart rate or to treat the underlying condition, suggesting opportunities to improve care of WCT in the ED.

RéSUMé: INTRODUCTION: Bien que la tachycardie à complexe large (wide complex tachycardia WCT) soit potentiellement mortelle, on sait peu de choses sur son incidence aux urgences ou sur l'expertise des médecins des urgences en matière de diagnostic et de traitement. Nous avons cherché à comparer les cas WCT aux urgences qui étaient des arythmies primaires par rapport à ceux avec une fréquence cardiaque rapide secondaire à des problèmes médicaux, ainsi que la précision du diagnostic des urgences et la pertinence du traitement. MéTHODES: Nous avons effectué un examen des dossiers médicaux dans les urgences d'un grand hôpital universitaire où travaillent 95 médecins et avons inclus des patients consécutifs sur 28 mois (2018-2020) présentant un WCT (fréquence cardiaque ≥120 bpm et QRS ≥120 ms). Les cas ont été jugés par deux médecins des urgences et un cardiologue pour l'exactitude du diagnostic ECG par rapport à la lecture cardiologique et pour l'exactitude du traitement conformément aux directives. RéSULTATS: Nous avons identifié 306 cas éligibles (0,2 % de toutes les visites aux urgences) : âge moyen 73,9 ans, hommes 66,0 %, admis 53,3 %, décédés aux urgences 2,3 %. Les arythmies primaires et les tachycardies secondaires étaient chacune de 50,0 % (IC 95 % 44,4-55,6 %). Les médecins des urgences ont interprété correctement 81,2 % des ECG. Les arythmies les plus fréquentes et les pourcentages d'interprétation correcte étaient les suivants : fibrillation auriculaire 42,7 % (95,0 %), flutter auriculaire 22,2 % (63,5 %), tachycardie sinusale 12,0 % (78,6 %) et tachycardie supraventriculaire (TSV) 11,1 % (68,0 %). Les traitements ont été jugés optimaux dans 84,3 % des WCT primaires et 86,9 % des WCT secondaires. Les traitements étaient sous-optimaux pour les raisons suivantes : médicament inapproprié (3,9 % pour le primaire contre 1,3 % pour le secondaire), incapacité à réduire la fréquence <100 avant le retour à domicile (9,1 % pour le primaire contre 34,4 % pour le secondaire) et absence de traitement de la cause sous-jacente dans 5,9 % du WCT secondaire. CONCLUSIONS: Les cas de WCT étaient répartis uniformément entre les arythmies primaires et les cas secondaires. Les médecins du service d'urgence ont correctement interprété l'ECG dans 81 % des cas, mais ont surévalué le flutter auriculaire et la TSV. Ils ont mis en œuvre des soins appropriés dans la plupart des cas, mais n'ont pas toujours réussi à contrôler adéquatement la fréquence cardiaque ou à traiter la maladie sous-jacente, ce qui laisse entrevoir des possibilités d'améliorer les soins de WCT au service d'urgence.

Return of Results Policies for Genomic Research: Current Practices and the Hearts in Rhythm Organization (HiRO) Approach.

Research teams developing biobanks and/or genomic databases must develop policies for the disclosure and reporting of potentially actionable genomic results to research participants. Currently, a broad range of approaches to the return of results exist, with some studies opting for nondisclosure of research results and others following clinical guidelines for the return of potentially actionable findings from sequencing. In this review, we describe current practices and highlight decisions a research team must make when designing a return of results policy, from informed consent to disclosure practices and clinical validation options. The unique challenges of returning incidental findings in cardiac genes, including reduced penetrance and the lack of clinical screening standards for phenotype-negative individuals, are discussed. Finally, the National Hearts in Rhythm Organisation (HiRO) Registry approach is described to provide a rationale for the selective return of field-specific variants to those participating in disease-specific research. Our goal is to provide researchers with a resource when developing a return of results policy tailored for their research program, based on unique factors related to study design, research team composition, and availability of clinical resources.

Prevalence of Left Atrial Appendage Thrombus in Patients Anticoagulated With Direct Oral Anticoagulants: Systematic Review and Meta-analysis.

BACKGROUND: Multiple studies have examined the prevalence of left atrial appendage thrombus (LAAT) in patients anticoagulated with direct oral anticoagulants (DOACs) and have reported conflicting results. METHODS: Studies reporting the prevalence of LAAT on transesophageal echocardiography (TEE) after 3 or more weeks of DOAC therapy were identified. The proportions of anticoagulated patients diagnosed with LAAT were pooled using random-effects models. Prespecified subgroup analyses by the indication of TEE (pre-atrial fibrillation [AF] ablation vs cardioversion) and TEE strategy (routine use vs selective) were conducted via stratification. RESULTS: Forty studies were identified: 22 full manuscripts and 18 abstracts. Only 11 studies performed TEE routinely. Most studies included patients with paroxysmal AF and low thromboembolic risk. The pooled prevalence of LAAT was 2.5% (95% confidence interval [1.6%-3.4%]). The prevalence of LAAT is lower in the pre-AF ablation group compared with pre-cardioversion (1.1% vs 4.0%, P = 0.033). Routine TEE strategy yielded a lower LAAT prevalence in both groups (0.1% vs 2.3%, P = 0.002 and 3.2% vs 5.8%, P = 0.432, respectively). CONCLUSION: The reported prevalence of LAAT on TEE in patients treated with DOACs is highly variable. Factors associated with a high LAAT prevalence were pre-cardioversion indication and selective TEE strategy. Routine use of TEE before AF ablation may not be warranted.

INTRODUCTION: De nombreuses études ont porté sur la prévalence des thrombi se formant dans l'appendice auriculaire gauche (TAAG) chez les patients qui reçoivent des anticoagulants oraux directs (AOD) et ont révélé des résultats contradictoires. MÉTHODES: Nous avons recensé les études qui ont fait état de la prévalence des TAAG à l'échocardiographie transœsophagienne (ETO) trois semaines ou plus après le traitement par AOD. Les modèles à effets aléatoires ont permis de regrouper les patients qui prenaient des anticoagulants et avaient reçu un diagnostic de TAAG. Nous avons réalisé les analyses de sous-groupes prédéterminés par l'indication d'ETO (fibrillation auriculaire [FA] avant l'ablation vs FA avant la cardioversion) et la stratégie d'utilisation de l'ETO (systématique vs sélective) grâce à la stratification. RÉSULTATS: Nous avons recensé 40 études : 22 manuscrits complets et 18 résumés. Seules 11 études portaient sur l'utilisation systématique de l'ETO. La plupart des études portaient sur des patients qui étaient atteints de FA paroxystique et exposés à un faible risque thromboembolique. La prévalence groupée de TAAG était de 2,5 % (intervalle de confiance à 95 % [1,6 %-3,4 %]). La prévalence de TAAG était plus faible dans le groupe de FA avant l'ablation que dans le groupe de FA avant la cardioversion (1,1 % vs 4,0 %, P = 0,033). La stratégie d'utilisation systématique de l'ETO a permis d'obtenir une prévalence plus faible de TAAG dans les deux groupes (0,1 % vs 2,3 %, P = 0,002 et 3,2 % vs 5,8 %, P = 0,432, respectivement). CONCLUSION: La prévalence de TAAG à l'ETO chez les patients traités par AOD varie beaucoup. Les facteurs associés à une prévalence élevée de TAAG étaient l'indication avant la cardioversion et la stratégie d'utilisation sélective de l'ETO. L'utilisation systématique de l'ETO avant l'ablation peut ne pas être justifiée.

Variant Reinterpretation in Survivors of Cardiac Arrest With Preserved Ejection Fraction (the Cardiac Arrest Survivors With Preserved Ejection Fraction Registry) by Clinicians and Clinical Commercial Laboratories.

BACKGROUND: Following an unexplained cardiac arrest, clinical genetic testing is increasingly becoming standard of care. Periodic review of variant classification is required, as reinterpretation can change the diagnosis, prognosis, and management of patients and their relatives. METHODS: This study aimed to develop and validate a standardized algorithm to facilitate clinical application of the 2015 American College of Medical Genetics and Association for Molecular Pathology guidelines for the interpretation of genetic variants. The algorithm was applied to genetic results in the Cardiac Arrest Survivors With Preserved Ejection Fraction Registry, to assess the rate of variant reclassification over time. Variant classifications were then compared with the classifications of 2 commercial laboratories to determine the rate and identify sources of variant interpretation discordance. RESULTS: Thirty-one percent of participants (40 of 131) had at least 1 genetic variant with a clinically significant reclassification over time. Variants of uncertain significance were more likely to be downgraded (73%) to benign than upgraded to pathogenic (27%; P=0.03). For the second part of the study, 50% (70 of 139) of variants had discrepant interpretations (excluding benign variants), provided by at least 1 team. CONCLUSIONS: Periodic review of genetic variant classification is a key component of follow-up care given rapidly changing information in the field. There is potential for clinical care gaps with discrepant variant interpretations, based on the interpretation and application of current guidelines. The development of gene- and disease-specific guidelines and algorithms may provide an opportunity to further standardize variant interpretation reporting in the future. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT00292032.

High-power, short-duration atrial fibrillation ablation compared with a conventional approach: Outcomes and reconnection patterns.

BACKGROUND: The effectiveness, safety, and pulmonary vein (PV) reconnection patterns of point-by-point high-power, short-duration (HPSD) ablation relative to conventional force-time integral (FTI)-guided strategies for atrial fibrillation (AF) ablation are unknown. OBJECTIVES: To compare 1-year freedom from atrial arrhythmia (AA), complication rates, procedural times, and PV reconnection patterns with HPSD AF AF ablation versus an FTI-guided low-power, long-duration (LPLD) strategy. METHODS: We compared consecutive patients undergoing a first ablation procedure for paroxysmal or persistent AF. The HPSD protocol utilized a power of 50 W and durations of 6-8 s posteriorly and 8-10 s anteriorly. The LPLD protocol was FTI-guided with a power of ≤25 W posteriorly (FTI ≥ 300g·s) and ≤35 W anteriorly (FTI ≥ 400g·s). RESULTS: In total, 214 patients were prospectively included (107 HPSD, 107 LPLD). Freedom from AA at 1 year was achieved in 79% in the HPSD group versus 73% in the LPLD group (p = .339; adjusted hazard ratio with HPSD, 0.67; 95% confidence interval, 0.36-1.23; p < .004 for non-inferiority). Procedure duration was shorter in the HPSD group (229 ± 60 vs. 309 ± 77 min; p < .005). Patients undergoing repeat ablation had a higher propensity for reconnection at the right PV carina in the HPSD group compared with the LPLD group (14/30 = 46.7% vs. 7/34 = 20.6%; p = .035). There were no differences in complication rates. CONCLUSION: HPSD AF ablation resulted in similar freedom from AAs at 1 year, shorter procedure times, and a similar safety profile when compared with an LPLD ablation strategy. Patients undergoing HPSD ablation required more applications at the right carina to achieve isolation, and had a significantly higher rate of right carinal reconnections at redo procedures.