University of Crete, School of Medicine, Department of Cardiology, Greece.
Int J Cardiol. 2013 Jul 31;167(2):335-41. doi: 10.1016/j.ijcard.2012.07.014. Epub 2012 Aug 11.
Non ischemic dilated cardiomyopathy poses a significant risk of malignant ventricular arrhythmias and subsequent sudden cardiac death. The pathologic and electrophysiological substrate implicated to arrhythmogenesis has been quite adequately defined over the last decades and multiple forms of myocardial fibrosis - diffuse, patchy or gross scarring - are being studied regarding their arrhythmogenic potential. Moreover, the recent demonstration and continuous expansion of knowledge regarding causative genes in dilated cardiomyopathy open a new chapter in the field of diagnosis and prognosis of these patients. Numerous noninvasive and invasive methods have been used to stratify patients according to sudden cardiac death level of risk. Severely reduced left ventricular systolic myocardial function, expressed mostly by left ventricular ejection function, NYHA functional class, syncope and invasive electrophysiological study with programmed electrical stimulation have been incorporated into international guidelines, though leaving significant proportions of primary prevention patients out of stratification schemes. Electrocardiographic markers, signal-averaged ECG, heart rate variability, heart rate turbulence, baroreflex sensitivity, heart rate recovery and T-wave alternans have given conflicting results in non ischemic dilated cardiomyopathy. During the last decade, cardiac magnetic resonance, especially with gadolinium enhancement, has made a step forward in defining the fibrotic substrate of such patients. Prospective studies have given promising results, demonstrating correlation between late gadolinium enhancement and ventricular arrhythmogenesis. Identification of patients with genetically caused dilated cardiomyopathy prone to sudden cardiac death and large prospective trials investigating cardiac magnetic resonance and its prognostic potential may be able to establish a new era in stratification schemes.
非缺血性扩张型心肌病会导致恶性室性心律失常和随后的心脏性猝死，风险显著增加。过去几十年中，已充分定义了与心律失常发生相关的病理和电生理基质，多种形式的心肌纤维化（弥漫性、斑片状或大瘢痕）正在研究其致心律失常的潜力。此外，最近关于扩张型心肌病中致病基因的不断发现和知识的扩展，为这些患者的诊断和预后开辟了新的篇章。已经使用了许多非侵入性和侵入性方法来根据心脏性猝死的风险水平对患者进行分层。严重降低的左心室收缩心肌功能，主要通过左心室射血功能、纽约心脏协会功能分类、晕厥和侵入性电生理研究中的程序电刺激来表示，已被纳入国际指南，尽管仍有很大比例的一级预防患者未被纳入分层方案。心电图标志物、信号平均心电图、心率变异性、心率震荡、压力反射敏感性、心率恢复和 T 波交替在非缺血性扩张型心肌病中得出了相互矛盾的结果。在过去十年中，心脏磁共振，特别是钆增强，在定义此类患者的纤维化基质方面取得了进展。前瞻性研究取得了有前景的结果，证明了晚期钆增强与室性心律失常发生之间的相关性。识别出易发生心脏性猝死的遗传性扩张型心肌病患者和大规模前瞻性试验，研究心脏磁共振及其预后潜力，可能能够开创分层方案的新时代。
