Cecchi Franco, Olivotto Iacopo, Baldi Massimo, Maron Martin S, Maron Barry J
Dipartimento cuore e vasi-S.Luca vecchio, Azienda Ospedaliera Universitaria Careggi, Florence 50129, Italy.
Zhonghua Xin Xue Guan Bing Za Zhi. 2009 Dec;37(12):1069-73.
Hypertrophic cardiomyopathy (HCM) is characterized by extreme clinical heterogeneity, ranging from sudden cardiac death to long-term disease progression and heart failure-related complications. Myocardial ischemia, occurring at the microvascular level, is a major determinant of clinical expression and outcome. Accordingly, the severity of this microvascular dysfunction has been shown to represent an early and powerful predictor of unfavorable outcome in HCM. The assessment of microvascular function in vivo is technically challenging, although critical to a truly comprehensive evaluation and risk stratification of HCM patients. Available technologies include positron emission tomography and cardiac magnetic resonance (CMR). Studies of regional myocardial blood flow using positron emission tomography have demonstrated that the vasodilator response to dipyridamole is impaired in most HCM patients, not only in the hypertrophied ventricular septum but also in the less hypertrophied or non-thickened left ventricular free wall. CMR also allows measurement of myocardial flow, although the technique is currently time-consuming and largely limited to research situations. CMR provides further insight into the effects of ischemia in HCM patients, by visualizing the distribution and extent of fibrosis at the intramyocardial level. Late gadolinium enhancement (LGE) is a potential predictor of risk in HCM patients, and is believed to largely reflect replacement fibrosis resulting from recurrent microvascular ischemia. LGE is associated with increased prevalence of ventricular arrhythmias, and associated with microvascular dysfunction. The present review is to provide a concise overview for the available evidence of microvascular ischemia and its consequences in HCM.
肥厚型心肌病（HCM）的特点是临床异质性极高，从心源性猝死到长期疾病进展以及与心力衰竭相关的并发症都有。发生在微血管水平的心肌缺血是临床表型和预后的主要决定因素。因此，这种微血管功能障碍的严重程度已被证明是HCM患者不良预后的早期且有力的预测指标。尽管对HCM患者进行真正全面的评估和风险分层至关重要，但体内微血管功能的评估在技术上具有挑战性。现有的技术包括正电子发射断层扫描和心脏磁共振成像（CMR）。使用正电子发射断层扫描对局部心肌血流的研究表明，大多数HCM患者对双嘧达莫的血管舒张反应受损，不仅在肥厚的室间隔，而且在肥厚程度较轻或未增厚的左心室游离壁也是如此。CMR也可以测量心肌血流，尽管该技术目前耗时较长且主要限于研究场景。CMR通过可视化心肌内纤维化的分布和范围，进一步深入了解HCM患者缺血的影响。延迟钆增强（LGE）是HCM患者风险的潜在预测指标，并且被认为在很大程度上反映了反复微血管缺血导致的替代性纤维化。LGE与室性心律失常的患病率增加相关，并且与微血管功能障碍相关。本综述旨在对HCM中微血管缺血及其后果的现有证据提供简要概述。
