Assessment of Radiation-Induced Malfunction in Cardiac Implantable Electronic Devices.

BACKGROUND: Radiation therapy (RT) is a standard cancer treatment modality, and an increasing number of patients with cardiac implantable electronic devices (CIEDs) are being referred for RT. The goals of this study were as follows: (i) to determine the incidence of CIED malfunction following RT; (ii) to characterize the various types of malfunctions that occur; and (iii) to identify risk factors associated with CIED malfunction following RT. METHODS: A retrospective study of patients with CIEDs who received RT between 2007 and 2018 at 4 Canadian centres (Sunnybrook Health Sciences Centre, Kingston General Hospital, Hamilton Health Sciences Centre, and University of Ottawa Heart Institute) was conducted. Patients underwent CIED interrogation after completion of RT, to assess for late damage to the CIEDs. Data on demographics, devices, and RT were compared for the primary outcome of device malfunction. RESULTS: Of 1041 patients with CIEDs who received RT, 811 patients with complete data were included. Device malfunctions occurred in 32 of 811 patients (4%). The most common device malfunctions were reduced ventricular/atrial sensing (in 13 of 32 [41%]), an increase in lead threshold (in 9 of 32 [22%]), lead noise (in 5 of 32 [16%]), and electrical reset (in 2 of 32 [6%]). Higher beam energy (≥ 10 MV) was associated with malfunction (P < 0.0001). Radiation dose was not significantly different between the malfunction and non-malfunction groups (58.3 cGy vs 65 cGy, respectively, P = 0.71). CONCLUSIONS: Although RT-induced CIED malfunctions are rare (occurring in 4% of patients with a CIED who undergo RT), collaborative efforts between radiation oncologists and cardiac rhythm device clinics to optimize CIED monitoring are needed, to detect and manage CIED malfunctions. Malfunctions are more common in patients receiving higher-beam energy ( ≥ 10 MV ) RT.

CONTEXTE: La radiothérapie (RT) est une modalité standard de traitement du cancer, et un nombre croissant de patients porteurs de dispositifs cardiaques électroniques implantables (DCEI) doivent recevoir un traitement de RT. Les objectifs de cette étude étaient les suivants : (i) déterminer l'incidence d'une défaillance du DCEI après une RT; (ii) caractériser les différents types de défaillances qui se produisent; (iii) déterminer les facteurs de risque associés à la défaillance du DCEI après une RT. MÉTHODOLOGIE: Une étude rétrospective des patients avec un DCEI ayant reçu une RT entre 2007 et 2018 dans quatre centres canadiens (Sunnybrook Health Sciences Centre, Kingston General Hospital, Hamilton Health Sciences Centre et Institut de cardiologie de l'Université d'Ottawa) a été menée. Le DCEI des patients a été interrogé après la fin de la RT, pour en évaluer les dommages tardifs. Les données sur les caractéristiques démographiques, les dispositifs et la RT ont été comparées pour le paramètre d'évaluation principal, soit la défaillance du dispositif. RÉSULTATS: Sur les 1 041 patients avec un DCEI ayant reçu une RT, 811 patients avec des données complètes ont été inclus. Des défaillances du dispositif sont survenues chez 32 des 811 patients (4 %). Les défaillances les plus fréquentes du dispositif étaient une détection ventriculaire/atriale réduite (chez 13 des 32 patients [41 %]), une augmentation du seuil de la sonde (chez 9 des 32 patients [22 %]), un bruit provenant de la sonde (chez 5 des 32 patients [16 %]) et une réinitialisation électrique (chez 2 des 32 patients [6 %]). Une énergie de faisceau plus élevée (≥ 10 MV) était associée à une défaillance (p < 0,0001). La dose de rayonnement ne présentait pas de différence significative entre le groupe où une défaillance a été constatée et l'autre groupe (58,3 cGy vs 65 cGy, respectivement, p = 0,71). CONCLUSIONS: Bien que les défaillances du DCEI causées par la RT soient rares (survenant chez 4 % des patients avec un DCEI qui subissent une RT), une collaboration est nécessaire entre les radio-oncologues et les cliniques de dispositifs de gestion du rythme cardiaque, afin d'optimiser la surveillance du DCEI et de détecter et de gérer ces défaillances. Les défaillances sont plus fréquentes chez les patients recevant une énergie de faisceau plus élevée au moment de la RT ( ≥ 10 MV ) .

Link between Brugada phenocopy and myocardial ischemia: Results from the International Registry on Brugada Phenocopy.

BACKGROUND: Brugada phenocopies clinical entities that have indistinguishable electrocardiographic (ECG) patterns from true congenital Brugada syndrome. However, they are induced by other clinical circumstances such as myocardial ischemia. The purpose of our study was to examine the clinical features and pathogenesis of ischemia-induced Brugada phenocopy (BrP). METHODS: Data from 17 cases of ischemia-induced BrP were collected from the International Registry (www.brugadaphenocopy.com). Data were extracted from these publications and authors were contacted to provide further insight into each case. RESULTS: Of the patients included in this study, 71% were male. Mean age was 59 ± 11 years (range: 38-76). Type-1 Brugada ECG pattern occurred in 15/17 (88%) of the cases, while a type-2 Brugada ECG pattern was observed in the other 2/17 (12%). In all cases, the Brugada ECG pattern resolved upon correction of the ischemia, indicating ischemia as the inducing circumstance. No arrhythmic events have been detected acutely or during the follow-up. Reported time to resolution ranged from 2 minutes to 5 hours. Provocative challenges using sodium channel blocking agents were performed in 7/17 cases (41%), and all failed to induce a Brugada ECG pattern (BrP Class A). The remaining 10/17 cases (59%) did not undergo provocative testing due to various clinical reasons. CONCLUSIONS: Myocardial ischemia is a commonly reported etiology of BrP. Importantly, this study found no association between BrP induced by myocardial ischemia and sudden cardiac death or malignant ventricular arrhythmias.

Brugada phenocopy during right coronary artery dissection.

CASE PRESENTATION: A 68-year-old female presented with non-ST-segment elevation myocardial infarction, and urgency coronary angiography was performed. The procedure was complicated with right coronary artery dissection leading to type-1 Brugada ECG pattern. DISCUSSION: Brugada phenocopies (BrP) are clinical entities that present with electrocardiograms identical to those found in Brugada Syndrome (BrS) but are the result of different medical conditions. This report provides evidence that atypical causes of myocardial ischemia may induce BrP. Appropriate electrocardiogram and clinical differentiation of Brugada phenocopy from true Brugada syndrome may prevent unnecessary treatments. Although patients with true high-risk BrS are candidates for ICD therapy, the natural history of BrP remains unknown and seems to be more benign, depending on the severity of the underlying condition.

Reduction in unnecessary ventricular pacing fails to affect hard clinical outcomes in patients with preserved left ventricular function: a meta-analysis.

Aims: Several pacing modalities across multiple manufacturers have been introduced to minimize unnecessary right ventricular pacing. We conducted a meta-analysis to assess whether ventricular pacing reduction modalities (VPRM) influence hard clinical outcomes in comparison to standard dual-chamber pacing (DDD). Methods and Results: An electronic search was performed using Cochrane Central Register, PubMed, Embase, and Scopus. Only randomized controlled trials (RCT) were included in this analysis. Outcomes of interest included: frequency of ventricular pacing (VP), incident persistent/permanent atrial fibrillation (PerAF), all-cause hospitalization and all-cause mortality. Odds ratios (OR) were reported for dichotomous variables. Seven RCTs involving 4119 adult patients were identified. Ventricular pacing reduction modalities were employed in 2069 patients: (MVP, Medtronic Inc.) in 1423 and (SafeR, Sorin CRM, Clamart) in 646 patients. Baseline demographics and clinical characteristics were similar between VPRM and DDD groups. The mean follow-up period was 2.5 ± 0.9 years. Ventricular pacing reduction modalities showed uniform reduction in VP in comparison to DDD groups among all individual studies. The incidence of PerAF was similar between both groups {8 vs. 10%, OR 0.84 [95% confidence interval (CI) 0.57; 1.24], P = 0.38}. Ventricular pacing reduction modalities showed no significant differences in comparison to DDD for all-cause hospitalization or all-cause mortality [9 vs. 11%, OR 0.82 (95% CI 0.65; 1.03), P= 0.09; 6 vs. 6%, OR 0.97 (95% CI 0.74; 1.28), P = 0.84, respectively]. Conclusion: Novel VPRM measures effectively reduce VP in comparison to standard DDD. When actively programmed, VPRM did not improve clinical outcomes and were not superior to standard DDD programming in reducing incidence of PerAF, all-cause hospitalization, or all-cause mortality.

Early Canadian Multicenter Experience With WATCHMAN for Percutaneous Left Atrial Appendage Closure.

BACKGROUND: There are limited data with WATCHMAN (Boston Scientific Corporation, Natick, MA, USA) for left atrial appendage (LAA) closure in patients with nonvalvular atrial fibrillation (AF) and contraindications to anticoagulation. The purpose of this study was to evaluate the safety and efficacy of WATCHMAN in our early Canadian experience. METHODS: We report our pooled consecutive series of patients who underwent WATCHMAN implantation at four major Canadian centers. Indications for LAA closure were CHADS2 ≥ 1 or CHA2 DS2 -VASc ≥ 2, and contraindication/intolerance to or failure on anticoagulation. Follow-up imaging was typically performed 1-6 months postprocedure. RESULTS: One hundred and six patients underwent LAA closure with WATCHMAN from May 2013 to October 2015. The mean age was 74.8 ± 7.7, mean CHADS2 score was 2.8 ± 1.2, CHA2 DS2 -VASc score was 4.3 ± 1.5, and HASBLED score was 3.2 ± 1.2. Permanent AF was present in 67.9% and paroxysmal AF in 32.1%. Indications for LAA closure were prior bleeding 89.6% (87 major bleeding and 8 minor bleeding), 9.4% were deemed high risk for bleeding, and 0.9% with recurrent strokes on warfarin. Procedural success was 97.2% (103 of 106), with one device embolization (snared percutaneously), one implant failure due to inadequate LAA depth, and one cardiac perforation requiring surgical repair before WATCHMAN implantation. The composite major safety event-rate was 1.9% (1 death and 1 device embolization). Mean hospital stay was 1.8 ± 4.7 days. Antithrombotic therapy postimplant included dual antiplatelet therapy in 76 of 103 (73.8%). Mean follow-up was 210 ± 182 days; there were two transient ischemic attacks, with estimated 66% reduction in thromboembolic events relative to CHADS2 predicted risk. CONCLUSION: In our early Canadian experience, WATCHMAN for LAA closure in patients contraindicated to anticoagulation appeared safe and effective.

Catheter Ablation as First-Line Therapy for Atrial Fibrillation: Ready for Prime-Time?

Current guidelines include atrial fibrillation (AF) catheter ablation as part of the management strategy in patients that have failed at least one oral antiarrhythmic drug treatment course. However, growing evidence derived from both randomized and non-randomized studies demonstrate lower rates of AF recurrence and AF burden in patients with paroxysmal AF that are naïve to antiarrhythmic drug treatment. Furthermore, progression from paroxysmal AF to persistent AF appears to be delayed by early catheter ablation of AF. The current review addresses the question of the best timing for ablation in patients with paroxysmal AF and provides the rationale for offering AF ablation as first-line therapy based on the most updated evidence available.

Double twiddle trouble, a new variant of twiddler syndrome.

The twiddler syndrome results in retraction and coiling of the lead in the pacemaker pocket with subsequent pacemaker malfunction. If the lead׳s parameters are not affected, then the problem can be corrected by lead repositioning. We describe the first reported case of a dramatic pacemaker lead coiling with a double level of lead compromise, with one of them being intra-cardiac. This condition affected our treatment strategy, as the repositioning of the lead was unfeasible.

Percutaneous left atrial appendage Closure for Thromboembolic Prevention in atrial Fibrillation / Cierre percutáneo de la orejuela izquierda para prevención tromboembólica en fibrilación auricular

Background: Atrial fibrillation (AF) produces a five-fold increase in the risk of stroke, and the exclusion of the left atrial appendage (LAA), the main source of thrombi, is an interesting therapeutic option in patients with contraindication for oral anticoagulation. Objectives: The goal of this study was to evaluate the initial experience, immediate results and outcome at 45 days of percutaneous closure of the LAA in patients with AF and high risk of thromboembolic events, in whom chronic oral anticoagulation was contrain-dicated. Methods: Twenty-two patients with non-valvular AF and a CHA2DS2-Vasc ≥2 in whom there was contraindication or impossibility of long-term oral anticoagulation underwent percutaneous closure of the LAA with the WATCHMANT device. The patients were evaluated 45 days after the procedure by clinical assessment and transesophageal echocardiography. Results: The implant was successful in 21 of 22 patients (95.4%). Median (interquartile range) age and CHA2DS2-VASc and HAS-BLED scores were 76 years (IQR 14.5), 5 (IQR 1.5) and 4 (IQR 1), respectively. Three (13.6%) periprocedural complications were observed: one cardiac tamponade requiring surgery, one concealed major bleeding and one pseudoaneurysm of the femoral artery. No device-related complications or thromboembolic events were observed during the 45-day follow-up. The LAA was adequately excluded in 95% of the cases. Conclusions: In our initial experience, the procedure is feasible, with an acceptable risk, and can be considered a therapeutic option in patients with AF and high thromboembolic risk who cannot receive oral anticoagulation.

Introducción: La fibrilación auricular (FA) incrementa cinco veces el riesgo de accidente cerebrovascular y la orejuela auricular izquierda (OI) es la principal fuente de formación de trombos, por lo que su exclusión se presenta como una alternativa terapéutica interesante en pacientes con contraindicación para la anticoagulación oral. Objetivos: Evaluar la experiencia inicial, los resultados del implante y la evolución a los 45 días del cierre percutáneo de la OI en pacientes con FA de riesgo tromboembólico alto en los cuales no podía emplearse la anticoagulación oral crónica. Material y métodos: Veintidós pacientes con FA no valvular y CHA2DS2-Vasc ≥2 en los que la anticoagulación a largo plazo estaba contraindicada o era impracticable fueron sometidos al cierre percutáneo de la OI con el dispositivo WATCHMAN®. Los pacientes fueron evaluados a los 45 días mediante control clínico y con ecocardiografía transesofágica. Resultados: El implante fue exitoso en 21 de los 22 pacientes (95,4%). Las medianas (rango intercuartil) de edad, CHA2DS2-VASc y HAS-BLED fueron 76 años (RIC 14,5), 5 (RIC 1,5) y 4 (RIC 1), respectivamente. Se observaron 3 (13,6%) complicaciones periprocedimiento: un taponamiento que requirió revisión quirúrgica, un sangrado mayor oculto y un seudoaneurisma femoral. Durante el seguimiento a 45 días no se observaron complicaciones relacionadas con el dispositivo ni eventos tromboembólicos. En el 95% de los casos, la OI se encontraba adecuadamente excluida. Conclusiones: En nuestra experiencia inicial, el procedimiento es factible con un riesgo aceptable, constituyéndose en una alternativa terapéutica en pacientes con FA de riesgo tromboembólico alto que no pueden recibir anticoagulantes orales.

[Hemodialysis to remove anticoagulant dabigatran during emergencies]. / Hemodiálisis para remover el anticoagulante dabigatrán en situaciones de urgencia.

Dabigatran is an oral anticoagulant from the class of the direct thrombin inhibitors, indicated for prevention of thromboembolic events in patients with non valvular atrial fibrillation. Unlike warfarin, dabigatran has no known antidote. Hemodialysis has been suggested as a method for removing dabigatran and thereby reducing its anticoagulant effect. We report the case of a patient with a known history of atrial fibrillation, treated with dabigatran, who was admitted for emergency abdominal surgery. At six hours after the last dose received, coagulation studies were altered. In absence of an antidote to reverse its effects, it was decided to perform hemodialysis. After three hours of dialysis coagulation parameters were improved and the patient underwent surgery without showing abnormal bleeding during surgery or in the postoperative period.

Hemodiálisis para remover el anticoagulante dabigatrán en situaciones de urgencia / Hemodialysis to remove anticoagulant dabigatran during emergencies

El dabigatrán es un nuevo inhibidor directo de la trombina, de administración oral, empleado para la prevención de eventos tromboembólicos en pacientes con fibrilación auricular no valvular. A diferencia de la warfarina, no se dispone de un antídoto conocido. La hemodiálisis ha sido sugerida como un método para remover el dabigatrán y reducir el efecto anticoagulante. Se presenta el caso de un paciente con antecedente de fibrilación auricular y medicado con dabigatrán, que fue admitido en el hospital para una cirugía abdominal de urgencia. A las seis horas de la última dosis recibida, los estudios de coagulación mostraban alteración. Ante la falta de antídoto para revertir los efectos, se decidió realizar hemodiálisis. Luego de tres horas de diálisis los parámetros de coagulación tendieron a normalizarse y el paciente fue operado sin presentar hemorragias anormales durante la cirugía o en el postoperatorio.

Dabigatran is an oral anticoagulant from the class of the direct thrombin inhibitors, indicated for prevention of thromboembolic events in patients with non valvular atrial fibrillation. Unlike warfarin, dabigatran has no known antidote. Hemodialysis has been suggested as a method for removing dabigatran and thereby reducing its anticoagulant effect. We report the case of a patient with a known history of atrial fibrillation, treated with dabigatran, who was admitted for emergency abdominal surgery. At six hours after the last dose received, coagulation studies were altered. In absence of an antidote to reverse its effects, it was decided to perform hemodialysis. After three hours of dialysis coagulation parameters were improved and the patient underwent surgery without showing abnormal bleeding during surgery or in the postoperative period.

Infarto agudo de miocardio en la República Argentina: Registro CONAREC XVII / Acute Myocardial Infarction in Argentina: CONAREC XVII Registry

Introducción El infarto agudo de miocardio (IAM) representa una de las principales causas de morbimortalidad en nuestro país. Tener datos sobre la realidad de esta entidad en la Argentina es de suma importancia como punto de partida para el desarrollo de políticas de prevención, así como para mejorar su tratamiento. Objetivo Describir variables demográficas, situaciones de estrés asociadas, tratamientos instaurados, tiempos en los que se implementaron, complicaciones intrahospitalarias y medicación al alta de pacientes ingresados con IAM en centros asociados al Consejo Argentino de Residentes de Cardiología (CONAREC). Material y métodos Entre diciembre de 2009 y julio de 2010 se incluyeron 1.182 pacientes consecutivos ingresados en 45 centros de todo el país con diagnóstico de IAM con o sin supradesnivel del segmento ST. Resultados La edad promedio fue de 64 ± 12 años; 705 pacientes presentaron IAM con supradesnivel del segmento ST (IAMCEST) y 477 IAM sin supradesnivel del segmento ST (IAMSEST). En el IAMCEST, la tasa de reperfusión fue del 92% de los pacientes elegibles, con la angioplastia como principal método (80%), con una demora prehospitalaria de 165 minutos y un tiempo puerta-balón de 80 minutos. En el IAMSEST se realizó coronariografía al 75% de los pacientes, con angioplastia al 46% de ellos. La principal complicación fue el desarrollo de insuficiencia cardíaca (22% en IAMCEST y 11% en IAMSEST), seguida por el sangrado y las arritmias. La mortalidad resultó del 8,8% en los IAMCEST y del 5,1% en los IAMSEST. Conclusiones Los pacientes con IAM que ingresan en centros con residencia médica presentan una tasa alta de reperfusión y tratamiento al egreso hospitalario, acorde a las recomendaciones internacionales. Encontramos aspectos para mejorar, como la elevada prevalencia de los factores de riesgo y los tiempos prehospitalarios prolongados, situaciones que no se han modificado en los últimos 15 años.

Introduction Acute myocardial infarction (AMI) is a major cause of morbidity and mortality in our country. It is very important to have data on the reality of this entity in Argentina as a starting point for the development of prevention policies and treatment improvement. Objective The aim of the study was to describe demographic variables, situations associated to stress, established treatments, implementation times, in-hospital complications and medication at discharge of patients with AMI admitted to centers associated to the Argentine Council of Residents in Cardiology (CONAREC). Methods Between December 2009 and July 2010, 1182 consecutive patients admitted to 45 centers across the country with a diagnosis of AMI with or without ST segment elevation were included in the study. Results Mean age was 64 ± 12 years; 705 patients presented AMI with ST segment elevation (STEMI) and 477 without ST segment elevation (NSTEMI). In the STEMI group, the reperfusion rate was 92% of eligible patients, with primary angioplasty in 80% of cases. In this group, prehospital time delay was 165 minutes and door-to-balloon time was 80 minutes. In the NSTEMI group), coronary angiography was performed in 75% of patients and 46% underwent angioplasty. The main complication was the development of heart failure (22% in the STEMI group and 11% in the NSTEMI group, followed by bleeding and arrhythmias. Mortality was 8.8% in the STEMI group and 5.1% in the NSTEMI group. Conclusions Patients with AMI admitted to centers with medical residency present with a high rate of reperfusion and treatment at hospital discharge, in agreement with international recommendations. We have found aspects to be improved such as the high prevalence of risk factors and prolonged prehospital time delays, situations which have not changed in the last 15 years.