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AIM: The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation. METHODS: A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate. STRUCTURE: Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.
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Fibrilação Atrial , Cardiologia , Tromboembolia , Humanos , American Heart Association , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Fibrilação Atrial/terapia , Fatores de Risco , Estados Unidos/epidemiologiaRESUMO
Previous reports indicate that IL18 is a novel candidate gene for diastolic dysfunction in sickle cell disease (SCD)-related cardiomyopathy. We hypothesize that interleukin-18 (IL-18) mediates the development of cardiomyopathy and ventricular tachycardia (VT) in SCD. Compared with control mice, a humanized mouse model of SCD exhibited increased cardiac fibrosis, prolonged duration of action potential, higher VT inducibility in vivo, higher cardiac NF-κB phosphorylation, and higher circulating IL-18 levels, as well as reduced voltage-gated potassium channel expression, which translates to reduced transient outward potassium current (Ito) in isolated cardiomyocytes. Administering IL-18 to isolated mouse hearts resulted in VT originating from the right ventricle and further reduced Ito in SCD mouse cardiomyocytes. Sustained IL-18 inhibition via IL-18-binding protein resulted in decreased cardiac fibrosis and NF-κB phosphorylation, improved diastolic function, normalized electrical remodeling, and attenuated IL-18-mediated VT in SCD mice. Patients with SCD and either myocardial fibrosis or increased QTc displayed greater IL18 gene expression in peripheral blood mononuclear cells (PBMCs), and QTc was strongly correlated with plasma IL-18 levels. PBMC-derived IL18 gene expression was increased in patients who did not survive compared with those who did. IL-18 is a mediator of sickle cell cardiomyopathy and VT in mice and a novel therapeutic target in patients at risk for sudden death.
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Anemia Falciforme/complicações , Cardiomiopatias/etiologia , Interleucina-18/sangue , Taquicardia Ventricular/etiologia , Adulto , Anemia Falciforme/sangue , Anemia Falciforme/fisiopatologia , Animais , Arritmias Cardíacas/sangue , Arritmias Cardíacas/etiologia , Arritmias Cardíacas/fisiopatologia , Cardiomiopatias/sangue , Cardiomiopatias/fisiopatologia , Humanos , Interleucina-18/análise , Masculino , Camundongos , Taquicardia Ventricular/sangue , Taquicardia Ventricular/fisiopatologia , Adulto JovemRESUMO
INTRODUCTION: Simulation technology has an established role in teaching technical skills to cardiology fellows, but its impact on teaching trainees to interpret coronary angiographic (CA) images has not been systematically studied. The aim of this randomized controlled study was to test whether structured simulation training, in addition to traditional methods would improve CA image interpretation skills in a heterogeneous group of medical trainees. METHODS: We prospectively randomized a convenience sample of 105 subjects comprising of medical students (N = 20), residents (N = 68) and fellows (N = 17) from the University of Arizona. Subjects were randomized in a stratified fashion into a simulation training group which received simulation training in addition to didactic teaching (n = 53) and a control training group which received didactic teaching alone (n = 52). The change in pre and post-test score (delta score) was analyzed by a two-way ANOVA for education status and training arm. RESULTS: Subjects improved in their post-test scores with a mean change of 4.6 ± 4.0 points. Subjects in the simulation training arm had a higher delta score compared to control (5.4 ± 4.2 versus 3.8 ± 3.7, p = 0.04), with greatest impact for residents (6.6 ± 4.0 versus 3.5 ± 3.4) with a p = 0.02 for interaction of training arm and education status. CONCLUSIONS: Simulation training complements traditional methods to improve CA interpretation skill, with greatest impact on residents. This highlights the importance of incorporating high-fidelity simulation training early in cardiovascular fellowship curricula.
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Internato e Residência , Treinamento por Simulação , Estudantes de Medicina , Competência Clínica , Simulação por Computador , Currículo , Humanos , EnsinoRESUMO
Coronavirus disease (COVID-19) is a serious illness caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The symptoms of the disease range from asymptomatic to mild respiratory symptoms and even potentially life-threatening cardiovascular and pulmonary complications. Cardiac complications include acute myocardial injury, arrhythmias, cardiogenic shock and even sudden death. Furthermore, drug interactions with COVID-19 therapies may place the patient at risk for arrhythmias, cardiomyopathy and sudden death. In this review, we summarise the cardiac manifestations of COVID-19 infection and propose a simplified algorithm for patient management during the COVID-19 pandemic.
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Doenças Cardiovasculares , Infecções por Coronavirus , Pandemias , Administração dos Cuidados ao Paciente/métodos , Pneumonia Viral , Algoritmos , Betacoronavirus/isolamento & purificação , Betacoronavirus/patogenicidade , COVID-19 , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/classificação , Doenças Cardiovasculares/terapia , Doenças Cardiovasculares/virologia , Infecções por Coronavirus/complicações , Infecções por Coronavirus/tratamento farmacológico , Infecções por Coronavirus/epidemiologia , Infecções por Coronavirus/fisiopatologia , Infecções por Coronavirus/terapia , Humanos , Pneumonia Viral/epidemiologia , Pneumonia Viral/fisiopatologia , Pneumonia Viral/terapia , SARS-CoV-2 , Tratamento Farmacológico da COVID-19RESUMO
Cardiac implanted electronic devices (CIEDs) have historically been regarded as a contraindication for performing magnetic resonance imaging (MRI), limiting the availability of this exam for large numbers of patients who may have otherwise benefited from the unique diagnostic capabilities of MRI. Interactions between CIEDs and the magnetic field associated with MRI systems have been documented, and include potential effects on CIED function, lead heating, and force/torque on the generator. Several device manufacturers have developed "MR-Conditional" CIEDs with specific hardware and software design changes to optimize the device for the MR environment. However, a substantial body of evidence has been accumulating that suggests that MRI may be safely performed in patients with either conditional or nonconditional CIEDs. Institutional policies and procedures, including preexam screening and assessment by skilled electrophysiology personnel and intraexam monitoring, allow MRI to be safely performed in CIED patients, as evidenced by at least two, large multicenter prospective studies and multiple smaller, single-institution studies. Cross-departmental collaboration and a robust safety infrastructure at sites that perform MRI should allow for the safe imaging of CIED patients who have a clinical indication for the study, regardless of the conditionality status of the device. LEVEL OF EVIDENCE: 5 Technical Efficacy: Stage 5 J. Magn. Reson. Imaging 2018;47:595-603.
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Imageamento por Ressonância Magnética , Marca-Passo Artificial , Segurança do Paciente , Animais , Desenho de Equipamento , Feminino , Humanos , Masculino , SuínosRESUMO
BACKGROUND: Observational studies have explored the safety of magnetic resonance (MR) scanning of patients with cardiac implantable electronic devices (CIEDs) that are not Food and Drug Administration approved for MR scanning ("nonconditional"). However, concern has been raised that MR scanning that includes the thoracic region may pose a higher risk. This study examines the safety of MR scanning of thoracic versus nonthoracic regions of patients with CIEDs. METHODS: Patients underwent MR scanning utilizing an institutional protocol. CIED variables examined included sensing value, pacing capture threshold, lead impedance, and battery voltage. Regression analysis of the CIED variable differences (pre- to immediately post-MR and pre-MR to long-term follow-up) was performed to determine if CIED variable differences were dependent on region scanned (thoracic vs nonthoracic), time from CIED implant to MR scanning, or CIED type (pacemaker vs implantable cardioverter defibrillator). RESULTS: 238 patients (38% female, age 65 ± 15 years) underwent 339 MR scans, including 99 MR scans of the thoracic region. CIED variable differences to immediately post-MR or to long-term follow-up were not significantly different from zero (P > 0.05) and there was no dependence upon region scanned (thoracic vs nonthoracic), time from CIED implant to MR scan, or CIED type. One power-on reset occurred in a patient that underwent a cardiac MR and the CIED was successfully reprogrammed. There were no clinical adverse effects. CONCLUSIONS: CIED variable differences following MR scan were not dependent on the region scanned (thoracic vs nonthoracic) and there were no clinical adverse effects in this prospective cohort.
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Desfibriladores Implantáveis , Imageamento por Ressonância Magnética/métodos , Marca-Passo Artificial , Segurança do Paciente , Tórax/diagnóstico por imagem , Idoso , Feminino , Humanos , Masculino , Estudos Prospectivos , Estudos RetrospectivosRESUMO
BACKGROUND: In retrospective swine and human investigations of ventricular fibrillation (VF) cardiac arrest, the amplitude-spectral area (AMSA), determined from the VF waveform, can predict defibrillation and a return of spontaneous circulation (ROSC). OBJECTIVES: We hypothesized that an algorithm using AMSA in real time to direct postshock chest compression (CC) duration would shorten the time to ROSC and improve neurological outcome in a swine model of VF cardiac arrest with acute myocardial infarction (AMI) or nonischemic myocardium. METHODS: AMI was induced by occlusion of the left anterior descending artery. VF was untreated for 10 min. Animals were randomized to either traditional resuscitation with 2 min of CC after each shock or to an AMSA-guided algorithm where postshock CCs were shortened to 1 min if the preshock AMSA exceeded 20 mV-Hz. RESULTS: A total of 48 animals were studied, 12 in each group (AMI vs. normal, and traditional vs. AMSA-guided). There was a nonsignificant shorter time to ROSC with an AMSA-guided approach in AMI swine (17.2 ± 3.4 vs. 18.5 ± 4.7 min, p = NS), and in normal swine (13.5 ± 1.1 vs. 14.4 ± 1.2, p = NS). Neurological outcome was similar between traditional and AMSA-guided animals. AMSA predicted ROSC (p < 0.001), and a threshold of 20 mV-Hz gave a sensitivity of 89%, with specificity of 29%. CONCLUSION: Although AMSA predicts ROSC in a swine model of VF arrest in both AMI and normal swine, a waveform-guided approach that uses AMSA to direct postshock CC duration does not significantly shorten the time to ROSC or alter neurological outcome.
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Algoritmos , Eletrocardiografia , Parada Cardíaca/terapia , Massagem Cardíaca , Infarto do Miocárdio/fisiopatologia , Fibrilação Ventricular/fisiopatologia , Animais , Reanimação Cardiopulmonar/métodos , Cardioversão Elétrica , Feminino , Parada Cardíaca/etiologia , Masculino , Modelos Animais , Infarto do Miocárdio/complicações , Valor Preditivo dos Testes , Suínos , Fatores de Tempo , Resultado do Tratamento , Fibrilação Ventricular/complicaçõesRESUMO
Purpose To examine the clinical effect of lead length and lead orientation in patients with cardiac implantable electronic devices (CIEDs) and lead fragments or abandoned leads undergoing 1.5-T MRI. Materials and Methods This Health Insurance Portability and Accountability Act-compliant retrospective study included patients with CIEDs and abandoned leads or lead fragments undergoing 1.5-T MRI from March 2014 through July 2020. CIED settings before and after MRI were reviewed, with clinically significant variations defined as a composite of the change in capture threshold of at least 50%, in sensing of at least 40%, or in lead impedance of at least 30% between before MRI and after MRI interrogation. Adverse clinical events were assessed at MRI and up to 30 days after. Univariable and multivariable analysis was performed. Results Eighty patients with 126 abandoned CIED leads or lead fragments underwent 107 1.5-T MRI examinations. Sixty-seven patients (median age, 74 years; IQR, 66-78 years; 44 male patients, 23 female patients) had abandoned leads, and 13 (median age, 66 years; IQR, 52-74 years; nine male patients, four female patients) had lead fragments. There were no reported deaths, clinically significant arrhythmias, or adverse clinical events within 30 days of MRI. Three patients with abandoned leads had a significant change in the composite of capture threshold, sensing, or lead impedance. In a multivariable generalized estimating equation analysis, lead orientation, lead length, MRI type, and MRI duration were not associated with a significant change in the composite outcome. Conclusion Use of 1.5-T MRI in patients with abandoned CIED leads or lead fragments of varying length and orientation was not associated with adverse clinical events. Keywords: Cardiac Assist Devices, MRI, Cardiac Implantable Electronic Device Supplemental material is available for this article. © RSNA, 2024.
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Desfibriladores Implantáveis , Falha de Equipamento , Imageamento por Ressonância Magnética , Marca-Passo Artificial , Humanos , Masculino , Feminino , Idoso , Desfibriladores Implantáveis/efeitos adversos , Estudos Retrospectivos , Marca-Passo Artificial/efeitos adversos , Pessoa de Meia-Idade , Falha de Equipamento/estatística & dados numéricosRESUMO
AIM: The "2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Patients With Atrial Fibrillation" provides recommendations to guide clinicians in the treatment of patients with atrial fibrillation. METHODS: A comprehensive literature search was conducted from May 12, 2022, to November 3, 2022, encompassing studies, reviews, and other evidence conducted on human subjects that were published in English from PubMed, EMBASE, the Cochrane Library, the Agency for Healthcare Research and Quality, and other selected databases relevant to this guideline. Additional relevant studies, published through November 2022, during the guideline writing process, were also considered by the writing committee and added to the evidence tables, where appropriate. STRUCTURE: Atrial fibrillation is the most sustained common arrhythmia, and its incidence and prevalence are increasing in the United States and globally. Recommendations from the "2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" and the "2019 AHA/ACC/HRS Focused Update of the 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation" have been updated with new evidence to guide clinicians. In addition, new recommendations addressing atrial fibrillation and thromboembolic risk assessment, anticoagulation, left atrial appendage occlusion, atrial fibrillation catheter or surgical ablation, and risk factor modification and atrial fibrillation prevention have been developed.
Assuntos
Fibrilação Atrial , Cardiologia , Tromboembolia , Humanos , Estados Unidos/epidemiologia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/terapia , Fibrilação Atrial/epidemiologia , American Heart Association , Fatores de RiscoRESUMO
BACKGROUND: Adoption and outcomes for conduction system pacing (CSP), which includes His bundle pacing (HBP) or left bundle branch area pacing (LBBAP), in real-world settings are incompletely understood. We sought to describe real-world adoption of CSP lead implantation and subsequent outcomes. METHODS: We performed an online cross-sectional survey on the implantation and outcomes associated with CSP, between November 15, 2020, and February 15, 2021. We described survey responses and reported HBP and LBBAP outcomes for bradycardia pacing and cardiac resynchronization CRT indications, separately. RESULTS: The analysis cohort included 140 institutions, located on 5 continents, who contributed data to the worldwide survey on CSP. Of these, 127 institutions (90.7%) reported experience implanting CSP leads. CSP and overall device implantation volumes were reported by 84 institutions. In 2019, the median proportion of device implants with CSP, HBP, and/or LBBAP leads attempted were 4.4% (interquartile range [IQR], 1.9-12.5%; range, 0.4-100%), 3.3% (IQR, 1.3-7.1%; range, 0.2-87.0%), and 2.5% (IQR, 0.5-24.0%; range, 0.1-55.6%), respectively. For bradycardia pacing indications, HBP leads, as compared to LBBAP leads, had higher reported implant threshold (median [IQR]: 1.5 V [1.3-2.0 V] vs 0.8 V [0.6-1.0 V], p = 0.0008) and lower ventricular sensing (median [IQR]: 4.0 mV [3.0-5.0 mV] vs. 10.0 mV [7.0-12.0 mV], p < 0.0001). CONCLUSION: In conclusion, CSP lead implantation has been broadly adopted but has yet to become the default approach at most surveyed institutions. As the indications and data for CSP continue to evolve, strategies to educate and promote CSP lead implantation at institutions without CSP lead implantation experience would be necessary.
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Bradicardia , Fascículo Atrioventricular , Humanos , Bradicardia/terapia , Estudos Transversais , Sistema de Condução Cardíaco , Doença do Sistema de Condução Cardíaco , Eletrocardiografia , Estimulação Cardíaca Artificial , Resultado do TratamentoRESUMO
Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.
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Cardiac physiologic pacing (CPP), encompassing cardiac resynchronization therapy (CRT) and conduction system pacing (CSP), has emerged as a pacing therapy strategy that may mitigate or prevent the development of heart failure (HF) in patients with ventricular dyssynchrony or pacing-induced cardiomyopathy. This clinical practice guideline is intended to provide guidance on indications for CRT for HF therapy and CPP in patients with pacemaker indications or HF, patient selection, pre-procedure evaluation and preparation, implant procedure management, follow-up evaluation and optimization of CPP response, and use in pediatric populations. Gaps in knowledge, pointing to new directions for future research, are also identified.
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Terapia de Ressincronização Cardíaca , Insuficiência Cardíaca , Criança , Humanos , Fascículo Atrioventricular , Resultado do Tratamento , Doença do Sistema de Condução Cardíaco , Terapia de Ressincronização Cardíaca/métodos , Insuficiência Cardíaca/terapia , Eletrocardiografia/métodosAssuntos
Taquicardia Supraventricular/terapia , Adolescente , Adulto , Fármacos Cardiovasculares/economia , Fármacos Cardiovasculares/uso terapêutico , Ablação por Cateter/economia , Criança , Pré-Escolar , Terapia Combinada , Análise Custo-Benefício , Tomada de Decisões , Técnicas de Diagnóstico Cardiovascular , Gerenciamento Clínico , Eletrocardiografia , Medicina Baseada em Evidências , Feminino , Humanos , Masculino , Gravidez , Complicações Cardiovasculares na Gravidez/terapia , Qualidade de Vida , Taquicardia Supraventricular/classificação , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/economia , Taquicardia Supraventricular/epidemiologia , Taquicardia Supraventricular/fisiopatologia , Adulto JovemAssuntos
Taquicardia Supraventricular/terapia , Adolescente , Adulto , Fármacos Cardiovasculares/economia , Fármacos Cardiovasculares/uso terapêutico , Ablação por Cateter/economia , Criança , Pré-Escolar , Terapia Combinada , Análise Custo-Benefício , Tomada de Decisões , Técnicas de Diagnóstico Cardiovascular , Gerenciamento Clínico , Eletrocardiografia , Medicina Baseada em Evidências , Feminino , Humanos , Masculino , Gravidez , Complicações Cardiovasculares na Gravidez/terapia , Qualidade de Vida , Taquicardia Supraventricular/classificação , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/economia , Taquicardia Supraventricular/epidemiologia , Taquicardia Supraventricular/fisiopatologia , Adulto JovemRESUMO
BACKGROUND: Patients with atrial fibrillation are increasingly prescribed a direct oral anticoagulant (DOAC) over warfarin and seek to avoid anticoagulation even without a history of major bleeding. This study explores the outcomes of patients implanted with a Watchman device in relation to anticoagulation choice (warfarin versus DOAC) in the post-procedure period and a history of bleeding. METHODS: Patients implanted with a Watchman device at a single center were retrospectively analyzed. Characteristics including anticoagulation in the first 45 days and history of major bleed were assessed and efficacy (thromboembolism) and safety (bleeding) outcomes compared by Kaplan-Meier analysis. RESULTS: Two hundred nine patients were implanted (57% male, age 74.6 ± 7.8 years) and followed for 23.5 ± 7.1 months. In the first half of patients, 98% were prescribed warfarin, which dropped to 51% in the second half (p < 0.0001). A history of major bleed was present in 80.8% of the first half of patients and decreased to 60% in the second half (p = 0.001). There were 16 safety and 4 efficacy events. There was no difference in safety outcomes according to history of major bleeding or anticoagulant choice in the first 45 days. There was no difference in efficacy outcomes over the duration of follow-up according to anticoagulation choice in the first 45 days. CONCLUSIONS: Patients implanted with a Watchman device were increasingly over time prescribed a DOAC and implanted without a history of major bleeding. Bleeding and thromboembolic events were infrequent and related neither to choice of anticoagulant nor to prior major bleeding.
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Apêndice Atrial , Fibrilação Atrial , Acidente Vascular Cerebral , Tromboembolia , Idoso , Idoso de 80 Anos ou mais , Anticoagulantes/efeitos adversos , Fibrilação Atrial/cirurgia , Feminino , Hemorragia/induzido quimicamente , Hemorragia/prevenção & controle , Humanos , Masculino , Estudos Retrospectivos , Tromboembolia/prevenção & controle , Resultado do Tratamento , Varfarina/efeitos adversosRESUMO
BACKGROUND: Vasopressors administered IV late during resuscitation efforts fail to improve survival. Intraosseous (IO) access can provide a route for earlier administration. We hypothesized that IO epinephrine after 1 minute of cardiopulmonary resuscitation (CPR) (an "optimal" IO scenario) after 10 minutes of untreated ventricular fibrillation (VF) cardiac arrest would improve outcome in comparison with either IV epinephrine after 8 minutes of CPR (a "realistic" IV scenario) or placebo controls with no epinephrine. METHODS: Thirty swine were randomized to IO epinephrine, IV epinephrine, or placebo. Important outcomes included return of spontaneous circulation (ROSC), 24-hour survival, and 24-hour survival with good neurological outcome (cerebral performance category 1). RESULTS: ROSC after 10 minutes of untreated VF was uncommon without administration of epinephrine (1 of 10), whereas ROSC was nearly universal with IO epinephrine or delayed IV epinephrine (10 of 10 and 9 of 10, respectively; P = 0.001 for either versus placebo). Twenty-four hour survival was substantially more likely after IO epinephrine than after delayed IV epinephrine (10 of 10 vs. 4 of 10, P = 0.001). None of the placebo group survived at 24 hours. Survival with good neurological outcome was more likely after IO epinephrine than after placebo (6 of 10 vs. 0 of 10, P = 0.011), and only 3 of 10 survived with good neurological outcome in the delayed IV epinephrine group (not significant versus either IO or placebo). CONCLUSION: In this swine model of prolonged VF cardiac arrest, epinephrine administration during CPR improved outcomes. In addition, early IO epinephrine improved outcomes in comparison with delayed IV epinephrine.
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Modelos Animais de Doenças , Epinefrina/administração & dosagem , Fibrilação Ventricular/tratamento farmacológico , Animais , Feminino , Infusões Intraósseas , Infusões Intravenosas , Masculino , Projetos Piloto , Distribuição Aleatória , Taxa de Sobrevida/tendências , Sus scrofa , Suínos , Fatores de Tempo , Fibrilação Ventricular/mortalidadeRESUMO
OPINION STATEMENT: For almost the past decade, recommendations for the use of implantable cardioverter defibrillators (ICDs) for primary prevention of sudden cardiac death have been based upon the left ventricular ejection fraction (LVEF). Current guidelines recommend an ICD for heart failure patients with LVEF ≤35% and NYHA functional class of II or III; however, because the majority of heart failure patients who qualify for ICD implantation based on these criteria will never have an event requiring ICD therapy over several years of follow-up, additional methods of risk stratification for sudden death are clearly needed. Additionally, most of the nearly 300,000 cardiac arrests that occur each year occur in patients without heart failure or significant left ventricular dysfunction. To improve the identification of patients at risk for sudden death, several criteria other than ejection fraction have been proposed and studied. Markers of autonomic tone, including heart rate turbulence and QT dynamicity, have shown some ability to predict total mortality but not arrhythmic events. Microvolt T-wave alternans testing was initially thought to be highly predictive of life-threatening arrhythmias, but prospective large sub-studies of the MADIT II and SCD-HeFT trials have failed to show a predictive value for T-wave alternans testing. Newer markers for risk are based upon the detection of myocardial fibrosis, which forms the substrate for re-entrant and malignant ventricular tachyarrhythmias. Markers of collagen turnover or quantification of myocardial scar by MRI may hold the best promise for identifying patients at highest risk for sudden cardiac death and may also identify patients at high risk but with an ejection fraction above 35%, who are not currently recommended for ICD implantation.
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Morte Súbita Cardíaca/prevenção & controle , Desfibriladores Implantáveis , Cardioversão Elétrica/instrumentação , Biomarcadores , Cardiomiopatias/terapia , Reanimação Cardiopulmonar , Morte Súbita Cardíaca/etiologia , Desenho de Equipamento , Falha de Equipamento , Parada Cardíaca/terapia , Insuficiência Cardíaca/terapia , Humanos , Estudos Multicêntricos como Assunto , Infarto do Miocárdio/terapia , Revascularização Miocárdica , Seleção de Pacientes , Período Pós-Operatório , Ensaios Clínicos Controlados Aleatórios como Assunto , Risco , Síncope/etiologia , Taquicardia Ventricular/complicações , Taquicardia Ventricular/prevenção & controle , Taquicardia Ventricular/terapia , Fatores de Tempo , Resultado do Tratamento , Troponina/sangue , Fibrilação Ventricular/complicações , Fibrilação Ventricular/prevenção & controle , Fibrilação Ventricular/terapiaRESUMO
OBJECTIVE: We have demonstrated that a return of spontaneous circulation in the first 3 mins of resuscitation in swine is predicted by ventricular fibrillation waveform (amplitude spectral area or slope) when untreated ventricular fibrillation duration or presence of acute myocardial infarction is unknown. We hypothesized that in prolonged resuscitation efforts that return of spontaneous circulation immediately after a second or later shock with postshock chest compression is independently predicted by end-tidal CO2, coronary perfusion pressure, and ventricular fibrillation waveform measured before that shock in a swine model of ischemic and nonischemic ventricular fibrillation arrest. DESIGN: Animal intervention study with comparison to a control group. SETTING: University animal laboratory. SUBJECTS: Twenty swine. INTERVENTIONS: Myocardial infarction was induced by steel plug occlusion of the left anterior descending coronary artery. Ventricular fibrillation was untreated for 8 mins in normal swine (n=10) and acute myocardial infarction swine (n=10). MEASUREMENTS AND MAIN RESULTS: End-tidal CO2, coronary perfusion pressure, and ventricular fibrillation waveform characteristics of amplitude spectral area and slope were analyzed before second or later shocks. For an amplitude spectral area>35 mV-Hz, the odds ratio for achieving return of spontaneous circulation after that shock was 72 (95% confidence interval, 3.8-1300; p=.004) compared with an amplitude spectral area<28 mV-Hz and with an area under the receiver operator characteristic curve of 0.86. For slope>3.6 mV/s, the odds ratio for achieving return of spontaneous circulation was 36 (95% confidence interval, 2.7-480; p=.007) compared with slope<2.72 mV/s with an area under the curve of 0.86. End-tidal CO2 and coronary perfusion pressure were not predictive of return of spontaneous circulation after a shock, although coronary perfusion pressure was significantly related to both amplitude spectral area (p<.001) and slope (p<.001). CONCLUSIONS: : In prolonged untreated ventricular fibrillation arrest, the waveform characteristics of amplitude spectral area and slope predict the attainment of return of spontaneous circulation with a second or later shock. This has implications for the ideal means to customize the timing of shocks and chest compressions when return of spontaneous circulation is not promptly obtained.