肥厚型心肌病与心源性猝死

肥厚型心肌病是最常见的遗传性心血管疾病,心源性猝死是其最恶劣的并发症,可以在各个年龄段发生。该病为35岁以下青年人和运动员发生心源性猝死的最主要原因。植入式心脏除颤器在预防猝死的发生方面取得了令人瞩目的成果,可以及时终止致命的恶性心律失常,挽救猝死高风险患者的生命。所以,判断哪些患者是心源性猝死的高危人群、哪些患者需进行ICD植入、如何进行危险分层至关重要。现有的危险评估模型仍有很大的局限性,需要更大规模的前瞻性研究及完整的数据采集以对其进行补充完善。     

Sudden cardiac death: Epidemiologic and financial worldwide perspective

The term sudden cardiac death (SCD) implies the sudden and unexpected loss of an active, productive member of the community. SCD is typically attributed to lethal ventricular arrhythmias; however, these arrhythmias are impossible to diagnose after the fact. Epidemiologic analyses, therefore, rely on inference of the cause of death. Estimates of the incidence of are SCD variable but it may be as high as 1 per 1,000 per year. The cost of SCD to society is incalculable. Current strategies for preventing SCD rely on risk assessment for cardiology patients and implantation of defibrillators (ICD) in high risk patients. Unfortunately, the absolute number of SCDs that occur in the general (relatively low-risk) population is large compared to the number of SCDs in the high risk population. Therefore, prevention of SCD in high risk populations is unlikely to prevent the majority of SCDs. Cost-effectiveness of ICD implantation for prevention of SCD has been studied; ICDs appear to meet U.S. and European criteria for cost-effectiveness if their benefit extends to at least 7–8 years. However, therapies considered cost-effective may nonetheless be too costly for most worldwide societies. Currently, investigators are focusing on refining risk stratification, partly in hopes of identifying patients for whom ICD implantation will not be useful.     

Sudden cardiac death preceded by ST segment elevations during ECG patch monitoring

A 58-year-old male underwent ambulatory ECG monitoring with continuous patch monitoring (Zio XT Patch) for the complaint of episodic dyspnea. In the period of monitoring the patient suffered sudden cardiac death (SCD) with continuous ECG recording showing pronounced ST segment elevations followed by bradycardia and death. This report highlights the growing potential of continuous ST segment monitoring, and features the infrequent entity of ischemic electromechanical dissociation with bradyarrhythmia as a cause of SCD.     

Sudden cardiac arrest with shockable rhythm in patients with heart failure

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Are women worldwide under-treated with regard to cardiac resynchronization and sudden death prevention?

Implantable cardioverter defibrillators (ICDs) have been demonstrated to improve survival in patients with serious structural heart disease. Likewise, cardiac resynchronization therapy (CRT) has assumed an important role in the treatment of patients with symptomatic heart failure because of its demonstrated value in improving functional class, quality of life, exercise capacity, and survival. However, these clinical trials have all primarily enrolled Caucasian males, raising the question as to whether other important subgroups benefit in a comparable way. Women have lower rates of sudden cardiac death (SCD) compared to men, and event rates lag 10–20 years behind those in men. Among patients with known coronary artery disease, women have one-fourth the risk of SCD found in men. Women with heart failure tend to present at an older age than men, and women more often have heart failure with preserved systolic function, a group in whom prophylactic ICD therapy for the prevention of SCD has not been studied. Despite these differences, analysis of clinical trial results shows that women have similar outcomes with ICD and CRT therapy compared to men. There is a lower percentage of women among device therapy patients both in clinical trials and in practice for reasons that are not clear, but at least some of the difference is likely due to differences in age at presentation and co-morbidities. In fact, device therapy overall appears to be under-utilized in both men and women, when implantation rates are compared to the prevalence of heart failure in the population as a whole.     

心源性猝死危险因素分析

目的探讨和分析心源性猝的危险因素。方法收集和整理在我院2012年04月-2013年10月诊治时发生心源性猝死的心肌患者64例为研究对象,对上述收集对象的临床资料进行整理和分析。结果本组单因素分析显示自发性持续室速、心室颤动(心脏骤停)、晕阙、左室流出道梗阻、非持续性室速等因素为心肌疾病患者发生心源性猝死的危险因素;多因素Logistic分析发现自发性持续性室速、心室颤动、晕阙以及猝死家族史是发生心源性猝死的重要危险因素。结论心肌疾病患者发生心源性猝死的为危险因素呈现综合化、多样化,临床治疗中应给予针对性的预防或治疗,这对降低心肌疾病患者心源性猝死率有着积极的意义。     

Five-year survival of patients after out-of-hospital cardiac arrest depending on age

Patient's age belongs to the independent prognostic factors of patients after out-of-hospital cardiac arrest (OHCA). This study aimed to evaluate the influence of age on 5-year survival in professionally cardio-pulmonary resuscitated patients with “primary cardiac” etiology OHCA. In this analysis of prospective multi-centric study, from April 1, 2002 until August 31, 2004, a total of 560 patients were included (aged 16-97 years) from the East Bohemian region, for whom a professional cardio-pulmonary resuscitation for OHCA was attempted. In the age subgroup <70 years there were 307 patients and in the age subgroup ≥70 years there were 253 patients. Of the subgroup <70 years, 29 patients (10%) survived to year 5 (58% from the 50 patients surviving to day 30), and in the subgroup ≥70 years, we had 4 patients surviving to year 5 (2%) (29% from the 14 patients surviving to day 30), respectively (Fisher‘s exact test; comparison in the all resuscitated patients: p < 0.001, in the population surviving to day 30: p = 0.071). In conclusion, there was a trend towards a worse outcome in 5-year survival following OHCA in the patients aged ≥70 years. Nevertheless, these data support that prognosis OHCA of elders is not associated with universal dismal outcome.     

Sudden death risk markers for patients with left ventricular ejection fractions greater than 40%

The major burden of sudden cardiac death (SCD) in patients with heart disease occurs in those with a left ventricular ejection fraction?>?40%. Although the annual risk of SCD may be lower in these patients compared to those with lower LVEF, their lifetime cumulative risk of SCD may be greater due to a better overall prognosis. It is plausible that those with LVEF?>?40% who are at highest risk of life-threatening arrhythmia will benefit from implantable cardioverter defibrillators. Features that identify patients with a LVEF?>?40% at high risk of SCD are urgently needed. We review existing studies examining SCD markers in this sub-group and discuss gaps in the current evidence base.     

Sudden cardiac death in Andersen-Tawil syndrome.

Andersen-Tawil syndrome (ATS) is an autosomal dominant or sporadic disorder characterized by periodic paralysis, dysmorphic features, and ventricular arrhythmias. Although ventricular tachycardia burden is quite high sudden cardiac death in ATS is rare. We describe a case with sudden cardiac death due to electrical storm a few days after ICD implantation in KCNJ2 mutation-negative ATS.     

Sudden death in the young

BACKGROUND: Sudden death is rare in young people, but it has a disproportionate impact on the community. OBJECTIVES: The purpose of this study was to determine the causes of sudden, natural death in persons aged 5-35 years. METHODS: All autopsies conducted at a forensic medicine facility in the years 1995-2004 (inclusive) were reviewed. This facility serves more than 2.5 million people in the eastern part of Sydney, Australia. Data collected included subject age, height, weight, gender, circumstances of death, and pathologic findings at autopsy. Deaths caused by trauma, accidental causes, drowning, and drug toxicity were excluded from analysis. RESULTS: There were 427 nontraumatic, sudden deaths in the 10-year period (70.7% male). Cardiac causes accounted for 56.4%, noncardiac causes 39.3%, and undetermined cause 4.3%. The most common cardiac cause of sudden death was presumed arrhythmia in those with no or minimal structural heart disease (29.0%). Other cardiac causes were acute myocardial infarction (24.5%), myocarditis (11.6%), hypertrophic cardiomyopathy (5.8%), aortic dissection (5.4%), and dilated cardiomyopathy (5.4%). More than two thirds of deaths caused by acute myocardial infarction occurred in the age group from 30-35 years. Sudden cardiac death occurred during physical activity in 10.8% of cases. Sudden cardiac death was reported in a first-degree relative in 4.5% of decedents. The most common noncardiac causes of sudden death were epilepsy (23.8%), intracerebral hemorrhage (23.8%), asthma (16.1%), and pulmonary embolism (12.5%). CONCLUSION: Presumed cardiac arrhythmia is the most common cause of sudden, natural death in the young. There was no reported history of sudden death among the relatives of most decedents.     

Sudden death and cardiac arrest without phenotype: the utility of genetic testing

Approximately 4% of sudden cardiac deaths are unexplained [the sudden arrhythmic death syndrome (SADS)], and up to 6–10% of survivors of cardiac arrest do not have an identifiable cardiac abnormality after comprehensive clinical evaluation [idiopathic ventricular fibrillation (IVF)]. Genetic testing may be able to play a role in diagnostics and can be targeted to an underlying phenotype present in family members following clinical evaluation. Alternatively, post-mortem genetic testing (the “molecular autopsy”) may diagnose the underlying cause if a clearly pathogenic rare variant is found. Limitations include a modest yield, and the high probability of finding a variant of unknown significance (VUS) leading to a low signal-to-noise ratio. Next generation sequencing enables cost-efficient high throughput screening of a larger number of genes but at the expense of increased genetic noise. The yield from genetic testing is even lower in IVF in the absence of any suggestion of another phenotype in the index case or his/her family, and should be actively discouraged at this time. Future improvements in diagnostic utility include optimization of the use of variant-calling pipelines and shared databases as well as patient-specific models of disease to more accurately assign pathogenicity of variants. Studying “trios” of parents and the index case may better assess the yield of sporadic and recessive disease.     

Sudden cardiac death in patients with nonischemic cardiomyopathy

Sudden cardiac death (SCD) is an important cause of mortality worldwide. Although SCD is most often associated with coronary heart disease, the risk of SCD in patients without ischemic heart disease is well-established. Nonischemic cardiomyopathies, including idiopathic dilated cardiomyopathy, hypertrophic cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy represent three unique disease entities that have been shown to be highly associated with SCD and ventricular arrhythmias. A variety of risk stratification tools have been investigated, although the optimal strategy remains unknown. Identification of the arrhythmogenic substrate and treatment of ventricular arrhythmias in these subgroups can be challenging. Herein, we aim to discuss the current understanding of the anatomic and electrophysiologic substrate underlying ventricular arrhythmias and highlight features that may be associated with a higher risk of SCD in these 3 conditions.     

Alcohol consumption and risk of ventricular arrhythmias and sudden cardiac death: An observational study of 408,712 individuals

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