Cardioverter-defibrillator reduces mortality risk in eligible ischemic and non-ischemic cardiomyopathy patients: Sub-analysis of the multi-center Improve SCA study

Background & Objective: Despite the burden of sudden cardiac arrest (SCA) worldwide, implantable cardioverter-defibrillators (ICDs) are underutilized, particularly in Asia, Latin America, Eastern Europe, the Middle East, and Africa. The Improve SCA trial demonstrated that primary prevention (PP) patients in these regions benefit from an ICD or a cardiac resynchronization therapy defibrillator (CRT-D). We aimed to compare the rate of device therapy and mortality among ischemic and non-ischemic cardiomyopathy (ICM and NICM) PP patients who met guideline indications for ICD therapy and had an ICD/CRT-D implanted. Methods: Improve SCA was a prospective, non-randomized, non-blinded multicenter trial that enrolled patients from the above-mentioned regions. All-cause mortality and device therapy were examined by cardiomyopathy (ICM vs NICM) and implantation status. Cox proportional hazards methods were used, adjusting for factors affecting mortality risk. Results: Of 1848 PP NICM patients, 1007 (54.5%) received ICD/CRT-D, while 303 of 581 (52.1%) PP ICM patients received an ICD/CRT-D. The all-cause mortality rate at 3 years for NICM patients with and without an ICD/CRT-D was 13.1% and 18.3%, respectively (HR 0.51, 95% CI 0.38e0.68, p < 0.001). Similarly, all-cause mortality at 3 years in ICM patients was 13.8% in those with a device and 19.9% in those without an ICD/CRT-D (HR 0.54, 95% CI 0.33e.0.88, p ¼ 0.011). The time to first device therapy, time to first shock, and time to first antitachycardia pacing (ATP) therapy were not significantly different between groups (p 0.263). Conclusions: In this large data set of patients with a guideline-based PP ICD indication, defibrillator device implantation conferred a significant mortality benefit in both NICM and ICM patients. The rate of appropriate device therapy was also similar in both groups.

Dispositivos cardíacos implantables y uso de resonancia magnética / Cardiac implantable devices and use of magnetic resonance / Dispositivos cardíacos implantáveis e utilização da ressonância magnética

El uso de la resonancia magnética (RM) en las distintas áreas de la medicina se ha expandido de manera significativa y de forma diaria se solicitan numerosos estudios. El hecho de que los resonadores pueden interaccionar con algunos objetos ha llevado a que históricamente se les niegue la realización de este estudio a pacientes portadores de dispositivos cardíacos porque se entiende que existen contraindicaciones absolutas. El avance de la tecnología de los dispositivos y la creciente evidencia publicada han cambiado este concepto. Nos proponemos revisar los mecanismos por los cuales un dispositivo implantable puede interactuar con el resonador y las implicancias clínicas que esto podría tener si las hubiera. La mayoría de los pacientes portadores de dispositivos cardíacos de estimulación podrán realizarse una RM, pero para que este procedimiento sea seguro es importante conocer las características y el tipo específico de dispositivo implantado. Proponemos finalmente puntos clave y algoritmos para tener en cuenta para el manejo adecuado de estos pacientes.

The use of magnetic resonance imaging (MRI) in different areas of medicine has expanded significantly and numerous procedures are indicated daily. The fact that resonators could interact with some objects has historically led to patients with cardiac devices being denied an MRI on the understanding that they suppose an absolute contraindication. Advances in device technology and the increasing evidence have changed this concept. We intend to review the mechanisms by which an implantable device could interact with the resonator and the clinical implications that this could have if any. Most patients will be able to undergo these studies, but to determine the safety of performing an MRI it is important to know the characteristics and specific type of implanted device. Finally, we provide key points and algorithms to take into account for these patients.

O uso da ressonância magnética em diferentes áreas da medicina tem se expandido significativamente e inúmeros exames são indicados diariamente. A possibilidade de que os ressonadores interajam com alguns objetos historicamente levou os pacientes com dispositivos cardíacos a terem a ressonância magnética negada por entender que existem contraindicações absolutas. Os avanços na tecnologia de dispositivos e o aumento das evidências publicadas mudaram esse conceito. Pretendemos revisar os mecanismos pelos quais um dispositivo implantável pode interagir com o ressonador e as implicações clínicas que isso pode ter, se houver. A grande maioria dos pacientes poderá se submeter a esses estudos, mas para determinar a segurança de realizar uma ressonância magnética é importante conhecer as características e o tipo específico de dispositivo implantado. Por fim, propomos pontos e algoritmos para a gestão dos pacientes.

Effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction

SUMMARY BACKGROUND/INTRODUCTION: Heart failure patients with reduced ejection fraction are at high risk for ventricular arrhythmias and sudden cardiac death. Ivabradine, a specific inhibitor of the If current in the sinoatrial node, provides heart rate reduction in sinus rhythm and angina control in chronic coronary syndromes. OBJECTIVE: The effect of ivabradine on ventricular arrhythmias in heart failure patients with reduced ejection fraction patients has not been fully elucidated. The aim of this study was to investigate the effect of ivabradine use on life-threatening arrhythmias and long-term mortality in heart failure patients with reduced ejection fraction patients. METHODS: In this retrospective study, 1,639 patients with heart failure patients with reduced ejection fraction were included. Patients were divided into two groups: ivabradine users and nonusers. Patients presenting with ventricular tachycardia, the presence of ventricular extrasystole, and ventricular tachycardia in 24-h rhythm monitoring, appropriate implantable cardioverter-defibrillator shocks, and long-term mortality outcomes were evaluated according to ivabradine use. RESULTS: After adjustment for all possible variables, admission with ventricular tachycardia was three times higher in ivabradine nonusers (95% confidence interval 1.5-10.2). The presence of premature ventricular contractions and ventricular tachycardias in 24-h rhythm Holter monitoring was notably higher in ivabradine nonusers. According to the adjusted model for all variables, 4.1 times more appropriate implantable cardioverter-defibrillator shocks were observed in the ivabradine nonusers than the users (95%CI 1.8-9.6). Long-term mortality did not differ between these groups after adjustment for all covariates. CONCLUSION: The use of ivabradine reduced the appropriate implantable cardioverter-defibrillator discharge in heart failure patients with reduced ejection fraction patients. Ivabradine has potential in the treatment of ventricular arrhythmias in heart failure patients with reduced ejection fraction patients.

ICD indication in hypertrophic cardiomyopathy: which algorithm to use?

SUMMARY OBJECTIVE: This study aimed to evaluate the agreement in the indication of implantable cardioverter-defibrillators in patients with Hypertrophic cardiomyopathy, as per the 2014 European Society of Cardiology and 2020 American Heart Association recommendations, and evaluate fragmented QRS as a predictor of cardiovascular outcome. METHODS: Retrospective cohort with 81 patients was evaluated between 2019 and 2021. Patients with hypertrophic cardiomyopathy ≥16 years old were included. Exclusion criteria include secondary myocardiopathy and follow-up <1 year. Kappa coefficient was used to determine the agreement. Survival and incidence curves were determined by Kaplan-Meier method. A p<0.05 was considered significant. RESULTS: The fragmented QRS was identified in 44.4% of patients. There were no differences between patients with and without fragmented QRS regarding clinical parameters, echocardiography, fibrosis, and sudden cardiac death risk. During follow-up of 4.8±3.4 years, there was no sudden cardiac death, but 20.6% patients with implantable cardioverter-defibrillator had at least one appropriate shock. Three of the seven appropriate shocks occurred in European Society of Cardiology low- to moderate-risk patients. Three shocks occurred in moderate-risk patients and four in American Heart Association high-risk patients. Overall recommendations agreement was 64% with a kappa of 0.270 (p=0.007). C-statistic showed no differences regarding the incidence of appropriate shock (p=0.644). CONCLUSION: sudden cardiac death risk stratification algorithms present discrepancies in implantable cardioverter-defibrillator indication, both with low accuracy.

Cardiodesfibrilador implantable: estado del arte / Cardiac defibrillators: state of the art

Resumen La muerte súbita cardiaca es una consecuencia devastadora de las enfermedades estructurales del corazón y un problema de salud pública en todo el mundo; es responsable de alrededor del 50% de las muertes por causa cardiovascular. Su incidencia es mayor en personas por encima de los de 40 años, siendo en esta población la cardiopatía isquémica instaurada o durante la fase aguda del infarto al miocardio los factores de riesgo más importantes; sin embargo, hay otros factores no relacionados con isquemia, como la cardiomiopatía dilatada, hipertrófica o valvular. La fibrilación y la taquicardia ventricular son la causa más frecuente de muerte súbita cardiaca en adultos. Los cardiodesfibriladores implantables son ampliamente utilizados y recomendados por las sociedades de cardiología para la prevención primaria y secundaria de la muerte súbita cardiaca.

Abstract Sudden cardiac death is a devastating consequence of structural heart disease and a global public health problem, accounting for close to 50% of cardiovascular deaths. Its incidence is greater in people over the age of 40, with the most important risk factors being: established ischemic heart disease or ischemia during the acute phase of a myocardial infarction. However, there are other factors, unrelated to ischemia, such as dilated, hypertrophic, or valvular cardiomyopathy. Ventricular fibrillation and tachycardia are the most frequent causes of sudden cardiac death in adults. Implantable cardioverter-defibrillators are widely used and recommended by cardiology societies for primary and secondary prevention of sudden cardiac death.

Patient with an implantable cardiac electrical stimulation device. What should the anesthesiologist know? / Paciente con dispositivo de estimulación eléctrica cardiaca implantable. ¿Qué debe saber el anestesiólogo?

Abstract Patients with implantable electric stimulation devices are challenging to the anesthesiologist since these cases demand a comprehensive knowledge about how the device operates, the indications for the implant and the implications that must be addressed during the perioperative period. This article is intended to provide the reader with clear and structured information so that the anesthesiologist will be able to safely deal with the situation of a patient with an implantable cardiac stimulation device, who has been programmed for emergent surgery. A search for the scientific evidence available was conducted in Pubmed / Medline, ScienceDirect, OVID, SciELO), for a non-systematic review. The incidence of the use of cardiac electric stimulation devices has been growing. Their operation is increasingly complex, and demands being constantly updated on the knowledge in the area.

Resumen El paciente portador de un dispositivo de estimulación eléctrica cardiaca implantable se convierte en un reto para el anestesiólogo debido a que implica un conocimiento integral que abarca su funcionamiento, las indicaciones que llevaron a su implante y las implicaciones que se deben abordar en el perioperatorio. Este artículo busca proporcionar al lector información clara y estructurada que le permita al anestesiólogo enfrentarse de forma segura al escenario de un paciente con un dispositivo de estimulación eléctrica cardiaca implantable programado para cirugía emergente. Se realizó una búsqueda de la evidencia científica disponible en bases de datos (Pubmed / Medline, ScienceDirect, OVID, SciELO), para una revisión no sistemática. La incidencia en el uso de dispositivos de estimulación eléctrica cardiaca viene en aumento. Su funcionamiento es cada vez más complejo lo cual implica una actualización permanente del conocimiento en esta área.

Muerte súbita cardíaca por fibrilación ventricular asociada a isquemia miocárdica, tratada por desfibrilador automático implantable / Sudden cardiac death due to ventricular fibrillation associated with myocardial ischemia, treated by implantable cardioverter defibrillator

Resumen: Reportamos el caso de un hombre de 67 años, con múltiples factores de riesgo cardiovascular, quien en el año 2015 presentó muerte súbita por fibrilación ventricular sin lesiones coronarias significativas, tras lo cual se implantó un desfibrilador automático. En el año 2019 presentó un nuevo episodio de fibrilación ventricular en relación con síndrome coronario agudo con supradesnivel del ST localizado en pared anterior, registrado y adecuadamente resuelto por el dispositivo. Se demostró una oclusión aterotrombótica en la porción proximal de la arteria descendente anterior. Fue precoz y exitosamente manejado con angioplastía coronaria percutánea e implante de stent fármaco activo, guiado por tomografía por coherencia óptica intracoronaria. A las 48 horas post angioplastía, presentó episodio de taquicardia ventricular polimorfa reconocido y tratado por el cardiodesfibrilador, sin consecuencias. Electivamente se efectuó angioplastía e implante de stent metálico en arteria coronaria derecha distal, con buen resultado angiográfico. La posterior evolución del paciente fue satisfactoria, sin manifestaciones de insuficiencia cardíaca, angina ni arritmias.

Abstract: A 67-year-old man, with multiple cardiovascular risk factors who in 2015 presented sudden death due to ventricular fibrillation without significant coronary lesions, after which an implantable automatic defibrillator (ICD) was implanted. In 2019, he presented a new episode of ventricular fibrillation adequately resolved by the device, in relation to an acute coronary syndrome with ST elevation in the anterior wall of the left ventricle, due to atherothrombotic occlusion in the proximal portion of the anterior descending artery. He was early and successfully managed with percutaneous coronary angioplasty by the insertion of a drug eluting stent, implanted guided by intracoronary optical coherence tomography. Forty eight hours later, he presented an episode polymorphic ventricular tachycardia recognized and treated by the ICD. Angioplasty with a bare metal stent implantation were performed in the distal right coronary artery, with good angiographic results. The subsequent course was satisfactory, with no manifestations of heart failure, angina or arrhythmias.

Infecção de loja de cardioversor-desfibrilador implantável (CDI) por klebsiella sp. Carbapenem-resistente / Klebsiella sp. carbapenem-resistant pocket infection of an Implantable Cardioverter Defibrillator (ICD)

RESUMO: As infecções associadas aos Dispositivos Cardíacos Eletrônicos Implantáveis (DCEI) apresentam uma incidência de até 3,4% e notável impacto na morbidade e mortalidade dos pacientes. As bactérias Gram-positivas, especialmente do gênero Staphylococcus sp. representam 60-70% dos agentes isolados. Por sua vez, as Gram-negativas correspondem até 9% dos casos. Relatamos uma infecção de loja de gerador de Cardioversor-desfibrilador implantável (CDI) por uma Klebsiella sp. resistente aos carbapenêmicos, em um paciente masculino jovem, cujo desafiador diagnóstico de certeza desse caso somente foi possível após exploração cirúrgica e cultura do material da loja do CDI, haja vista a apresentação clínica oligossintomática. Embora já descritas, Klebsiella sp. são raras nesse contexto e em nosso conhecimento, esse é o primeiro relato de uma infecção de DCEI por uma enterobactéria resistente a carbapenêmico. (AU)

ABSTRACT: Infections associated with Implantable Electronic Cardiac Devices (IECD) have an incidence of up to 3.4% and a notable impact on patient morbidity and mortality. Gram-positive bacteria, especially Staphylococcus sp. represent 60-70% of isolated agents. In turn, gram-negatives account for up to 9% of cases. We report an Implantable Cardioverter-Defibrillator (ICD) generator pocket infection by a Carbapenem Resistant Klebsiella sp., in a young male patient, whose challenging diagnosis of certainty was only possible after surgical exploration and culture of the material from the ICD pocket, given the oligosymptomatic clinical presentation. Although already described, Klebsiella sp. are rare in this context and to our knowledge, this is the first report of an IECD infection by a carbapenem-resistant enterobacterium. (AU)

Implantable cardioverter-defibrillator prevents sudden death in patients with Chagas cardiomyopathy in the Brazilian Amazon

Abstract Chagas disease (CD), with approximately 10,000 deaths annually, has become a worldwide health problem. Approximately 35% of cases may show cardiac manifestations such as arrhythmias and/or conduction disorders, heart failure, thromboembolic accidents, and sudden death. The Amazon region has long been considered a non-endemic area for CD; however, in the last decades, with an increase in the number of acute and chronic cases, disease evolution has received greater attention. Here, we report the successful implementation of a cardioverter-defibrillator for the prevention of sudden death in a patient with autochthonous Chagas cardiomyopathy in the Brazilian Amazon.

Seguimiento del paciente con cardiodesfibrilador automático implantable / Follow-up of the patient with automatic implantable cardioverter-defibrillator

RESUMEN Introducción: Los cardiodesfibriladores mejoran la supervivencia de los pacientes con riesgo de muerte súbita cardíaca. Existen escasos datos en nuestro país acerca de su eficacia en el seguimiento. Objetivo: Describir la evolución en el seguimiento de los pacientes con primoimplante de un cardiodesfibrilador automático. Método: Estudio ambispectivo, longitudinal, en 47 pacientes con primoimplante de un cardiodesfibrilador en el período septiembre de 2007 a diciembre de 2016, con cierre el 31 de diciembre de 2017. La probabilidad acumulada de supervivencia se estimó a través de las curvas de Kaplan-Meier. Resultados: La edad media fue de 57 ± 14,6 años, con predominio del sexo masculino (74,5%) y la indicación en prevención secundaria (83%). Presentaron terapias apropiadas el 57,4% de los pacientes, terapias inapropiadas un 23,4%, proarritmia del cardiodesfibrilador un 14,9% y tormenta arrítmica el 12,8% de los pacientes. Las terapias apropiadas se relacionaron con la fracción de eyección ≤ 35% (p=0,022) y la edad (p=0,031). La supervivencia acumulada libre del primer evento a los cuatro años fue 34,7%. La mortalidad cardiovascular se relacionó con: existencia de cardiopatía estructural (p=0,044), fracción de eyección ≤ 35% (p<0,001), clase funcional III-IV (p=0,046), terapias apropiadas (p=0,014) y tormenta arrítmica (p=0,002). La supervivencia acumulada libre de mortalidad cardiovascular fue de 70,7% al cuarto año. Conclusiones: La supervivencia de los pacientes con cardiodesfibrilador es buena. La mortalidad se asocia a un mayor deterioro del estado cardiovascular y a las terapias del dispositivo.

ABSTRACT Introduction: Implantable cardioverter-defibrillators improve the survival of patients at risk of sudden cardiac death. There is relatively little data in our country about their follow-up effectiveness. Objective: To describe the outcome of patients with primo-implantation of an automatic cardioverter-defibrillator during follow-up. Methods: An ambispective longitudinal cohort study was conducted in 47 patients with primo-implantation of a cardioverter-defibrillator in the period September 2007 to December 2016, ending on December 31, 2017. The cumulative probability of survival was estimated through the Kaplan-Meier curves. Results: Mean age was 57 ± 14.6 years, with male predominance (74.5%) and indication in secondary prevention (83%). Adequate therapies were found in 57.4% of patients, inadequate therapies in 23.4%, implantable cardioverter-defibrillator proarrhythmia in 14.9% and arrhythmic storm in 12.8% of patients. Adequate therapies were related to an ejection fraction ≤ 35% (p=0.022) and age (p=0.031). Cumulative free survival from the first event at four years was 34,7%. Cardiovascular mortality was related to: existence of structural heart disease (p=0.044), ejection fraction ≤ 35% (p<0.001), functional class III-IV (p=0.046), adequate therapies (p=0.014) and arrhythmic storm (p=0.002). Cumulative free survival of cardiovascular mortality was 70.7% at the fourth year. Conclusions: The survival of patients with implantable cardioverter-defibrillator is satisfactory. Mortality is associated with further deterioration of cardiovascular status and with device therapies.

Anaesthetic management of a patient with non compaction cardiomyopathy for implantable cardioverter defibrillator lead replacement

Non compaction cardiomyopathy (NCM) is a rare, primary genetically derived cardiomyopathy with a variable clinical presentation ranging from absence of symptoms to congestive heart failure, systemic thromboembolism, arrythmias and sudden cardiac death. Being an uncommon condition, the perioperative concerns in a patient with NCM have not been studied much. With increasing awareness and improved diagnostic tools including high resolution echocardiography and cardiac MRI, there has been an increase in the reporting of cases which stresses on the need for a complete understanding of this form of cardiomyopathy and its perioperative anaesthetic management. Authors report the case of a 24 years old female, with NCM who underwent prophylactic Implantable cardioverter defibrillator (ICD) insertion 5 years ago and was now posted for ICD removal and replacement in view of inappropriate ICD functioning.

Anesthetic management in a patient with arrhythmogenic right ventricular cardiomyopathy and an implantable cardioverter defibrillator: a case report / Anestesia para paciente com cardiomiopatia arritmogênica do ventrículo direito portador de cardioversor desfibrilador implantável: descrição de caso

Abstract Background and objectives: Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a genetic cardiomyopathy characterized by potentially lethal ventricular tachycardia. Here we describe a patient with ARVC and an Implantable Cardioverter Defibrillator (ICD) in whom maxillary sinus surgery was performed under general anesthesia. Case report: The patient was a 59 year-old man who was scheduled to undergo maxillary sinus surgery under general anesthesia. He had been diagnosed as having ARVC 15 years earlier and had undergone implantation of an ICD in the same year. Electrocardiography showed an epsilon wave in leads II, aVR, and V1-V3. Cardiac function was within normal range on transthoracic echocardiography. The ICD was temporarily deactivated after the patient arrived in the operating room and an intravenous line was secured. An external defibrillator was kept on hand for immediate defibrillation if any electrocardiographic abnormality was detected. Remifentanil 0.3 µg/kg/min, fentanyl 0.1 mg, propofol 154 mg, and rocuronium 46 mg were administered for induction of anesthesia. Tracheal intubation was performed orally. Anesthesia was maintained oxygen 1.0 L.min−1, air 2.0 L.min−1, propofol 5.0-7.0 mg.kg−1.h−1, and remifentanil 0.1-0.25 µg.kg−1.min−1. The surgery was completed as scheduled and the ICD was reactivated. The patient was then extubated after administration of sugammadex 200 mg. Conclusion: We report the successful management of anesthesia without lethal arrhythmia in a patient with ARVC and an ICD. An adequate amount of analgesia should be administered during general anesthesia to maintain adequate anesthetic depth and to avoid stress and pain.

Resumo Introdução e objetivo: A Cardiomiopatia Arritmogênica do Ventrículo Direito (CAVD) é uma cardiomiopatia genética caracterizada por taquicardia ventricular potencialmente letal. Descrevemos um paciente com CAVD com Cardioversor Desfibrilador Implantável (CDI) submetido a anestesia geral para cirurgia de seio maxilar. Relato do caso: Paciente masculino, 59 anos, a ser submetido a anestesia geral para cirurgia de seio maxilar. O paciente foi diagnosticado com CAVD há 15 anos, momento em que foi submetido a implante de CDI. A eletrocardiografia mostrou onda épsilon nas derivações II, aVR e V1-V3. O ecocardiograma transtorácico revelou função cardíaca normal. Após a entrada do paciente na sala de cirurgia, o CDI foi temporariamente desativado e uma via intravenosa foi instalada. Um desfibrilador externo foi mantido próximo ao paciente caso fosse detectada alguma anormalidade eletrocardiográfica que indicasse desfibrilação do paciente. Foram administrados 0,3 mg/kg/min de remifentanil, 0,1 mg de fentanil, 154 mg de propofol e 46 mg de rocurônio para indução da anestesia. A intubação traqueal foi realizada por via oral. A anestesia foi mantida com 1 L/min de oxigênio, 2 L/min de ar, 5-7 mg/kg/h de propofol e 0,1-0,25 µg/kg/min de remifentanil. O procedimento cirúrgico proposto foi concluído e o CDI foi reativado. O tubo traqueal foi retirado após administração de 200 mg de sugamadex. Conclusão: Descrevemos técnica de anestesia bem sucedida sem arritmia letal em paciente com CAVD e CDI. Analgesia adequada deve ser administrada durante a anestesia geral para manter profundidade anestésica correta e evitar estresse e dor.

Progress in application of implantable cardioverter defibrillators in children / 中华实用儿科临床杂志

Implantable cardioverter defibrillator (ICD) plays an irreplaceable role in preventing sudden cardiac death.There has been a continuous increase in the implantation rate of ICD in children along with technologic improvement.However,the choice of indication,device and implantation approaches of ICD still faces great challenges due to the particularity of children.Related issues on the clinical application of ICD in children,including common diseases,indications and the clinical application of ICD,are reviewed in this paper.

Progress in application of implantable cardioverter defibrillators in children / 中华实用儿科临床杂志

Implantable cardioverter defibrillator (ICD) plays an irreplaceable role in preventing sudden cardiac death.There has been a continuous increase in the implantation rate of ICD in children along with technologic improvement.However, the choice of indication, device and implantation approaches of ICD still faces great challenges due to the particularity of children.Related issues on the clinical application of ICD in children, including common diseases, indications and the clinical application of ICD, are reviewed in this paper.

Clinical Impact of Implantable Cardioverter-Defibrillator Therapy and Mortality Prediction Model for Effective Primary Prevention in Korean Patients

BACKGROUND: Studies on the efficacy of implantable cardioverter-defibrillator (ICD) therapy for primary prevention in Asian patients are relatively lacking compared to those for secondary prevention. Also, it is important to stratify which patients will benefit from ICD therapy for primary prevention.METHODS: Of 483 consecutive patients who received new implantation of ICD in 9 centers in Korea, 305 patients with reduced left ventricular systolic function and/or documented ventricular fibrillation/tachycardia were enrolled and divided into primary (n = 167) and secondary prevention groups (n = 138).RESULTS: During mean follow-up duration of 2.6 ± 1.6 years, appropriate ICD therapy occurred in 78 patients (25.6%), and appropriate ICD shock and anti-tachycardia pacing occurred in 15.1% and 15.1% of patients, respectively. Appropriate ICD shock rate was not different between the two groups (primary 12% vs. secondary 18.8%, P = 0.118). However, appropriate ICD therapy rate including shock and anti-tachycardia pacing was significantly higher (primary 18% vs. secondary 34.8%, P = 0.001) in the secondary prevention group. Type of prevention and etiology, appropriate and inappropriate ICD shock did not affect all-cause death. High levels of N-terminal pro-B-type natriuretic peptide, New York Heart Association functional class, low levels of estimated glomerular filtration ratio, and body mass index were associated with death before appropriate ICD shock in the primary prevention group. When patients were categorized in 5 risk score groups according to the sum of values defined by each cut-off level, significant differences in death rate before appropriate ICD shock were observed among risk 0 (0%), 1 (3.6%), 2 (3%), 3 (26.5%), and 4 (40%) (P < 0.001).CONCLUSION: In this multicenter regional registry, the frequency of appropriate ICD therapy is not low in the primary prevention group. In addition, combination of poor prognostic factors of heart failure is useful in risk stratification of patients who are not benefiting from ICD therapy for primary prevention.

Pseudo inappropriate shock: A technical dilemma

With liberal availability of high end cardiac implantable devices in recent era, we frequently encounter patients who are recipients of implantable cardioverter defibrillators (ICDs) in our routine clinical practice. Despite improvements in shock detecting algorithms by various manufacturers, incidence of inappropriate shock therapy remains high, it is cause of distress to physicians and patients. Here we present an interesting case of inappropriate shock in one of patient.

Update on Sports Participation for Athletes with Implantable Cardioverter Defibrillators

Prior statements have recommended restriction from competitive sports participation for all athletes with ICDs. Recent data, however, suggests that many athletes can participate in sports without adverse events. In the ICD Sports Registry, 440 athletes, aged 8-60 years, 77 of which were high-level interscholastic athletes, who had continued to practice sports, were prospectively followed for 4 years, with no deaths or failures to defibrillate during practice, and no injuries related to arrhythmia or shock during sports. Shocks did occur, for ventricular and supraventricular arrhythmias. While more athletes received shocks during physical activity than at rest, there were no differences between competition or practice, versus other physical activity. Programming with higher rate cut-offs and longer durations was associated with fewer inappropriate shocks, with no increase in syncope. Based on this study, current recommendations now state that returning to competition may be considered for an athlete with an ICD. In considering this decision, the underlying disease and type of sport should be discussed, and shared decision-making between doctor, patient, and often family, is critical

The Burden and Risk Factors for Infection of Transvenous Cardiovascular Implantable Electronic Device: a Nationwide Cohort Study

BACKGROUND AND OBJECTIVES: There are limited published data on the incidence and cost associated with cardiac implantable electrical device (CIED) infection for Asian patients. We analyzed the infection burden associated with the implantation of CIEDs in Korea. METHODS: In the Health Insurance Review & Assessment Service (HIRA) database during the period from January 1, 2014 to December 31, 2016, we identified 16,908 patients with CIED implantation. CIED infection was defined as either: 1) Infection-related diagnosis code by the Korean Standard Classification of Diseases after any CIED procedure; or 2) CIED removal along with systemic infection. RESULTS: The proportions of first implantation and replacement were 77.6% and 22.4%, respectively. During the follow-up period of 17.1±10.6 months, a total of 462 patients had CIED infection with incidence of 1.95 per 100 person-years with higher infection rate in replacement than first implantation (3.97 vs. 1.4 per 100 person-years, p<0.001). The average cost per person was US$ 16,584 (pacemaker, $13,736; implantable cardioverter defibrillator, $28,402; cardiac resynchronization therapy, $29,674). The risk factors of CIED infection were generator replacement (adjusted hazard ratio [aHR], 3.14; 95% confidence interval [CI], 2.60–3.78), diabetes mellitus (aHR, 1.94; 95% CI, 1.58–2.38), and congestive heart failure (aHR, 1.86; 95% CI, 1.51–2.28). CONCLUSIONS: The rate of CIED infection in Korea was 1.95 per 100 person-years with average cost of US$ 16,584. The most important risk factor was generator replacement. This result suggests that generator replacement should be performed cautiously to avoid CIED infection.

Impact of LDB3 gene polymorphisms on clinical presentation and implantable cardioverter defibrillator (ICD) implantation in Chinese patients with idiopathic dilated cardiomyopathy / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Objective: Mutations in LIM domain binding 3 (LDB3) gene cause idiopathic dilated cardiomyopathy (IDCM), a structural heart disease with a complicated genetic background. However, the association of polymorphisms in the LDB3 gene with susceptibility to IDCM in Chinese populations remains unexplored as dose the impact on clinical presentation. Methods: We sequenced all exons and the adjacent part of introns of the LDB3 gene in 159 Chinese Han IDCM patients and 247 healthy controls. Then we detected the distribution of polymorphisms in the LDB3 gene in all participants and assessed their associations with risk of IDCM. Additionally, we conducted a stratified genotypephenotype correlation analysis. Results: The A allele of rs4468255 was significantly associated with IDCM (P<0.01). The rs4468255, rs11812601, rs56165849, and rs3740346 were also associated with diastolic blood pressure (DBP) and left ventricular ejection fraction (LVEF) (P<0.05). Notably, a higher frequency of rs4468255 polymorphism was observed in implantable cardioverter defibrillator (ICD) recipients under a recessive model (P<0.01), whereas the significant association disappeared after adjusting for potential confounders. However, in the dominant model, notable correlations could only be observed after adjusting for multi parameters. Conclusions: The rs4468255 was significantly correlated with IDCM of Chinese Han population. A allele of rs4468255 is higher in IDCM patients with ICD implantation, suggesting the influence of genetic background in the generation of this response. In addition, rs11812601, rs56165849, and rs3740346 in LDB3 show association with brain natriuretic peptide, DBP, and LVEF levels in patients with IDCM but did not show any association with IDCM susceptibility.