室性心律失常的危险分层及评价方法

室性心律失常的危险分层及评 价方法 浙江大学医学院附属第一医院 陶谦民 背景 对于个人和家庭而言，因恶性室性心律失 常导致的心脏性猝死完全可以称之是一次 “ 地震 ”！ 目前对于心脏性猝死的预测，虽然经过了 四十多年的努力，仍然没有实质性的、确 切有效的方法。 我们只是通过检出高危人群，预防性应用 ICD，尽力去避免不幸的发生。 其实，在我们的身边，经常在 出现 图 动态心电图记录的心脏性猝死 非侵入性检查评估方法 心电学及相关检查是对室性心律失常危险分层的 常用方法。常规 12导联心电图、心电图运动试验 、动态心电图用以确定心律失常的诊断， QT间期 的改变、 ST改变、 T波电交替等反映复极的影响 ，对某些状况下的危险分层具有重要意义。 T波电 交替是唯一能判断是否发展到致命性室性心律失 常的危险分层指标（ IIa类推荐、 A级证据）；信 号平均心电图、心率变异、压力反射敏感性及心 率紊乱仅能作为不十分可靠的检测技术指标推荐 （ IIb类推荐、 B级证据） Microvolt T-wave alternans testing for ventricular arrhythmia risk stratification T-wave alternans tests prognostic horizon exceeds two years in analysis The finding addresses a persisting question about the test used to screen candidates for primary- prevention ICDs: if its negative, how soon should it be repeated? (Chan PS et al. Am J Cardiol 2008; 102:280-284.) Could it be that easy? Clinical-risk score may further stratify low-LVEF ICD candidates A retrospective analysis of none other than the MADIT-2 trial identified five familiar markers that could potentially be used to screen out post-MI, low-LVEF patients unlikely to need the devices. (Goldenberg I et al. J Am Coll Cardiol 2008:51:288-296.) Markers of autonomic tone advance in post-MI risk assessments In two studies, long-term prognostic measures included baroreflex sensitivity, heart-rate variability, and heart-rate turbulence. One found that the risk assessment didnt predict CV events unless it was performed later than usual, 10 to 14 weeks after the MI. (De Ferrari GM et al. Exner DV et al. J Am Coll Cardiol 2007; 50:2285-2290, 2275-2284.) Trials mixed message challenges TWA tests image for predicting sudden-death risk A mountain of data supports a risk-stratification role for microvolt TWA testing in candidates for primary-prevention ICDs, so how could the MASTER 1 trial suggest that it doesnt predict life- threatening ventricular arrhythmias in post-MI patients with poor LV function? (American Heart Association 2007 Scientific Sessions.) MASTER I: Disappointment for T-wave alternans testing The test did not predict life-threatening ventricular tachyarrhythmic events in patients with MADIT- 2 criteria for ICD implantation and therefore should not be used to stratify ICD use in this group, researchers said. (American Heart Association 2007 Scientific Sessions.) ALPHA strengthens case for TWA risk stratification in nonischemic HF The randomized trial adds to limited data suggesting that the T-wave-alternans test can sharpen the selection of patients most likely to need ICDs for primary prevention. (Salerno-Uriarte JA et al. J Am Coll Cardiol; published online before print October 29, 2007.) 侵入性检查评估方法 心脏电生理检查（ EP）是通过记录基础状 态和应用药物时心内电刺激对心律的影响 ，用以评估室性心律失常并对 SCD进行危 险分层，用以记录 VT是否可诱发、指导射 频消融治疗、评价药物疗效、 VT再发及 SCD的发生风险、评估心律失常是否是晕 厥的原因及 ICD治疗的适应证。 左室射血分数（ LVEF） 已成 为评估 SCA非常重要的 独立危 险因素 1 1 Myerberg RJ,Castellanos A.Cardiac arrest and sudden cardiac death.Braunwald E.Heart Disease,A Textbook of Cardiovascular Medicine.5th ed,Vol.Philadelphia:WB Saunders Co;1997:chapter 24 LVEF85%，遂 二期植入药物支架一枚，在 PCI术后三个月，突 发胸闷痛、气急，重复造影证实左旋支支架内血 栓形成伴左心功能不全，经 PCI血流恢复，重新 植入支架， 发生支架内血栓后，患者心功能下降明显，室性 早搏明显增多，有短阵室性心动过速。心脏增大 不明显，但室壁活动度较差（临床过程类似于反 复发生心肌梗死导致的心肌硬化性质的缺血性心 肌病）。 我们的体会 1.应该说， ICD作为严重冠心病和扩张型心肌病，伴 有心律失常的病人，有明确的一级预防的应用指 征。 2.病例的选择，当然依据国外的指南，心脏扩大伴 有 EF下降，就有植入指征，