Prehospital resuscitation and sudden cardiac death

Rates of survival horn pre-hospital cardiac arrest are often used to judge the quality of emergency medical systems. Despite many advances in technology and pharmacotherapy over the last two decades, overall survival rates in most systems remain disappointing. Objective analysis of different systems of care and associated outcomes has been hampered by a lack of uniform data reporting. Attempts to improve survival must focus on the key to resuscitation from sudden cardiac death, that is rapid response defibrillation.     

心源性猝死的院前诊断及复苏中的几个问题

目的：探讨心源性猝死的院前早期诊断,提高复苏成功率、方法分析24例心源性猝死的临床资料,结果24例中10例复苏成功,8例恢复心跳后于1－3天内死亡,其中5例平均血糖为21．6mmol/L,血钠156mmol/L,6例复苏失败,结论本文猝死病例中,由急性心肌梗死（AMI）引起者占70．83％,AMI早期诊断主要根据临床表现,不可因早期心电图检查没有表现出来轻易否定诊断而误诊,心脏骤停必须立即就地复苏,合理使用纳洛酮及碳酸氢钠、注意防治再灌注损伤综合征。在复苏中出现高糖、高钠血症者,其预后极差。     

Preventing sudden cardiac death

An exciting new era has begun in the management of patients who either have survived or are at risk for lethal ventricular arrhythmias. Electrophysiologic testing, a remarkably safe procedure, can be used to guide selection of the best protective drug regimen. A new device, the automatic implantable cardioverter-defibrillator, continuously monitors the heart rate and converts sustained ventricular tachyarrhythmias to normal sinus rhythm. Drs Lehmann and Steinman anticipate a significant reduction of the death rate in these patients in the coming years.     

Preventing sudden cardiac death

The syndrome of sudden cardiac death, which claims the lives of hundreds of thousands of Americans each year, is usually caused by ventricular tachycardia or fibrillation. Electrophysiologic testing is now being used to prevent recurrence of this syndrome in successfully resuscitated persons. With this procedure, antiarrhythmic drugs are assessed in terms of their ability to prevent induction of sustained ventricular tachyarrhythmias, rather than their ability to merely suppress ventricular premature beats. In medically unresponsive patients, an automatic cardioverter-defibrillator can be implanted to provide maximal protection from sudden cardiac death caused by ventricular tachyarrhythmias.     

Pathology of sudden cardiac death

Sudden unexpected cardiac death generally occurs in persons with previously unrecognized heart disease. It has become evident that it occurs often enough in patients without any identifiable structural abnormality. Although mechanical cardiac function may seem normal, such patients might have certain discrete anatomic abnormalities, such as myocarditis, focal myocardial fibrosis, hypertrophy of Purkinje-like myocytes, and myocardial disarray. The pathophysiology in patients with acute myocardial infarction (atherothrombosis of the coronary arteries) was discussed.     

Mechanisms of sudden cardiac death

Despite recent advances in preventing sudden cardiac death (SCD) due to cardiac arrhythmia, its incidence in the population at large has remained unacceptably high. Better understanding of the interaction among various functional, structural, and genetic factors underlying the susceptibility to, and initiation of, fatal arrhythmias is a major goal and will provide new tools for the prediction, prevention, and therapy of SCD. Here, we review the role of aberrant intracellular Ca handling, ionic imbalances associated with acute myocardial ischemia, neurohumoral changes, and genetic predisposition in the pathogenesis of SCD due to cardiac arrhythmia. Therapeutic measures to prevent SCD are also discussed.     

Risk stratification and primary prevention of sudden cardiac death: sudden death prevention

The initial challenge in primary prevention of sudden cardiac death (SCD) lies in identifying those at greatest risk, before the index event. Ventricular fibrillation is the leading cause of SCD; however, many clinical conditions predispose fatal ventricular dysrhythmias. In patients with structural heart disease, left ventricular dysfunction is the strongest predictor of SCD. Noninvasive markers such as nonsustained ventricular tachycardia, delayed potentials, decreased heart rate variability and baroreflex sensitivity, and repolarization alternans are further observed to assess risk in ischemic cardiomyopathy; however, most of these markers have poor positive predictive value and lack specificity. The electrophysiologic study has strong positive predictive value, but remains a costly and invasive method for risk stratification. In patients with normal hearts, genetic predisposition may identify patients at risk but clinical markers are not readily recognized. The implantable loop recorder is a useful tool in detecting dysrhythmic causes of syncope and identifying patients at risk for SCD.     

Behavioral states and sudden cardiac death.

Remarkable progress has been made both experimentally and clinically in defining the influence of behavioral states on susceptibility to life-threatening arrhythmias. Biological models have been developed to emulate anger and fear and have permitted detailed study of the intermediary mechanisms involved in stress-induced ischemia and ventricular fibrillation. The studies highlight the importance of adrenergic factors and the pathological significance of the poststress state. Clinically, the role of daily stresses in inducing silent myocardial ischemia and arrhythmias has been extensively characterized, and standardized behavioral stress tests have become available. Certain sleep states have been found to provoke ischemic episodes and arrhythmias. In particular, phasic rapid eye movement (REM) sleep has been shown both in animals and humans to conduce to perfusion abnormalities and propensity to fibrillation. Episodic surges in sympathetic nervous system activity appear to be the underlying basis. These conceptual and practical advances illustrate the promise of behavioral cardiology in the diagnosis and treatment of individuals at risk for sudden cardiac death.     

心脏猝死的危险分层问题

心脏猝死（sudden cardiac death）是常见的死亡方式之一,也是最具悲剧性质的死亡形式。多年来，人们一直希望能通过危险分层来找出心脏猝死的高危患者，制定预防策略，进而避免或明显减少心脏猝死患者。然而，由于种种原因，这些努力至今仍收效甚微。     

Electrocardiographic predictors of sudden cardiac death

Sudden cardiac death (SCD) is widespread and the most serious of the cardiac diseases, accounting for over half of cardiovascular mortality in adults in the United States, and nearly 1 in 3 of these patients does not report symptoms of cardiac disease before the sudden death. Quantifying the left ventricular ejection fraction is currently the best way to risk-stratify patients for SCD and identify those who are most likely to benefit from the insertion of an implantable cardiac defibrillator (ICD). The strategy of systemically placing ICDs in patients at risk of SCD is expensive and leads to substantial psychological hardship. However, noninvasive electrocardiographic indices of depolarization and repolarization may better identify patients who are at an increased risk of SCD. Therefore, developing an approach to identify electrocardiographic changes associated with the highest risk of arrhythmic death could markedly improve patient selection for ICD therapy. This report describes electrocardiographic parameters that may be useful in identifying patients at risk of SCD. The state of the science currently suggests that it is unlikely that a single electrocardiographic parameter will predict SCD, but rather a risk stratification algorithm based on a combination of electrocardiographic parameters may yield the best result.     

心脏性猝死高危病人家庭成员心肺复苏培训方法的研究

[目的]探讨适合我国国情的对心脏性猝死高危病人家庭成员的心肺复苏(CPR)培训方法,提高心脏性猝死高危病人家庭成员心肺复苏能力。[方法]采取对照研究的方法,将猝死高危病人家庭成员150人作为观察组进行心肺复苏培训,培训采取两级培训的方法,即先对社区医生,再由社区医生对家庭成员进行培训;将社区公众130人作为对照组,直接对其进行心肺复苏培训。分别对两组培训前、培训后即刻、培训后半年心肺复苏知识掌握情况进行问卷调查。[结果]观察组培训后即刻回答问题的正确率显著提高,且明显高于对照组。[结论]先对社区医生进行CPR培训,再由社区医生对猝死高危病人家属进行一对一个体CPR培训,可以有效地提高对心脏性猝死急救知识的掌握程度,是一项行之有效的方法。     

Molecular and genetic basis of sudden cardiac death

The abrupt cessation of effective cardiac function due to an aberrant heart rhythm can cause sudden and unexpected death at any age, a syndrome called sudden cardiac death (SCD). Annually, more than 300,000 cases of SCD occur in the United States alone, making this a major public health concern. Our current understanding of the mechanisms responsible for SCD has emerged from decades of basic science investigation into the normal electrophysiology of the heart, the molecular physiology of cardiac ion channels, fundamental cellular and tissue events associated with cardiac arrhythmias, and the molecular genetics of monogenic disorders of heart rhythm. This knowledge has helped shape the current diagnosis and treatment of inherited arrhythmia susceptibility syndromes associated with SCD and has provided a pathophysiological framework for understanding more complex conditions predisposing to this tragic event. This Review presents an overview of the molecular basis of SCD, with a focus on monogenic arrhythmia syndromes.     

家属心肺复苏培训对提高心脏猝死高危患者存活率的影响

目的 探讨分析心脏猝死高危患者家属进行心肺复苏培训对提高患者存活率的影响。方法 选择重庆医科大学附属第二医院心内科住院部2012年2月至2016年6月收治的610名心脏猝死高危患者的家属为研究对象。利用随机抽签法将其分为两组,观察组305名患者家属接受系统的心肺复苏培训方案;对照组305名患者家属只接受床旁健康宣教及公休会等。分析两组患者心脏骤停后存活率及其家属对急救知识及技能的掌握情况。存活的定义为患者心脏骤停经复苏抢救,患者出现自主心搏、自主呼吸,且在高级生命支持下存活时间＞24 h。存活率=（心脏骤停后存活人数/心脏骤停事件总例数）×100%。结果 观察组患者家属对心脏猝死诱因、防治措施、心脏骤停判断等方面知识的掌握情况均好于对照组（P＜0.05）;观察组患者家属应急反应时间平均为（81.02±37.01）s,明显短于对照组（169.62±30.69）s;观察组患者家属护理满意度97.05%,明显优于对照组83.28%。随访1年,观察组患者存活率（88.51%）高于对照组（70.45%）,差异有统计学意义（P＜0.05）。结论 对心脏猝死高危患者家属进行心肺复苏培训,能够有效提高家属的急救水平及应急能力,利于提高患者存活率。     

猝死复苏后的监护及护理

心脏性猝死主要为致命性心律失常所致。包括致死性快速心律失常、严重缓慢性心律失常和心室停顿[1],是心内科最主要的死亡原因。由于发生猝死因素的不确定性和多发性,因而,心肺复苏不易成功。即使复苏好转后也常再发生危象。心电监护技术可为心肺复苏提供有效的病情资料,也为治疗方案的制定提供确切依据。因此,心电监护和正确及时的护理为巩固复苏的成果,防止心脏再次停跳,最终脱离危险,具有不可替代的作用。同时,临床实践也对监护和护理不断提出新的要求。现将猝死心肺复苏后的监护和护理介绍如下。1临床资料2004年我科共收治心血管病人761…