肥厚型心肌病猝死危险因素分层

Risk stratification for sudden death in hypertrophic cardiomyopathy

肥厚型心肌病（HCM）是最常见的遗传性心脏病。普通人群患病率1／500，以自然病史差异极大为特征。很多患者终生无症状，寿命与常人并无不同。有些患者有心力衰竭（心衰）或心房颤动（房颤）的症状，某些患者猝死。猝死者常常先前没有症状，年龄较轻。HCM是青年人和运动员最常见的猝死原因。因此对猝死危险进行分层，预防猝死是一个重要的临床问题。

The natural history of hypertrophic cardiomyopathy （HCM） is extremely heterogeneous. Many patients remain asymptomatic throughout life, some develop severe symptoms of heart failure, but others die suddenly, often in the absence of previous symptoms and at a young age. Therefore, identification of those patients at high risk of sudden death represents a major clinical problem and has become an even greater challenge since the implantable cardioverter-defibrillator （ICD） has proved to be highly effective in preventing sudden death in HCM. Patients who have survived a cardiac arrest, or one or more episodes of sustained ventricular tachycardia, are considered to be at high risk and are candidates for an ICD. However, this patient subset represents a small proportion of the HCM population. The greatest difficulty concerns the identification of high risk patients who are candidates for primary prevention of sudden death with a prophylactic ICD. Decisions are based on generally accepted clinical markers which are associated with increased risk, including： family history of sudden death, extreme left ventricular （LV） wall thickness （ ≥ 30 mm）, nonsustained ventrieular tachyeardia on Holter monitoring, unexplained （non-neurocardiogenic） syncope particularly in young patients, and hypotensive blood pressure response to exercise. Patients with end-stage HCM or a LV apical aneurysm represent important arrhythmogenic subsets also associated with substantially increased risk. Multiple or single strong risk markers are associated with increased sudden death risk and justify consideration for a prophylactic ICD.