74例老年冠心病患者无症状心肌缺血临床探讨

Chinical value of silent myocardial ischemia in aged patients with coronary heart disease.

目的探讨老年冠心病患者无症状心肌缺血(SM1)的临床特点和发生规律。方法:对74例冠心病患者应用24h动态心电图检测(DCG)。按临床特征分为3组:Ⅰ组:单纯SMI;Ⅱ组:心绞痛患者伴有SMI;Ⅲ组:心肌梗死后有SMI发作。结果共检出心肌缺血634阵次,SMI的发生显著高于有症状心肌缺血,占90.22%。发作高峰在上午6～12点,ⅠⅡⅢ组的SMI发作次数、持续时间、ST段压低幅度依次增加,心肌缺血幅度与病情呈正相关,而与心率变异性(HRV)呈负相关。00～06点最少,但夜间缺血持续时间及ST段压低幅度明显重于白昼。结论SMI是冠心病最常见的表现形式,应和有症状心肌缺血同样给予足够重视。冠心病患者心脏自主神经受损程度随着心肌缺血程度而加重。

Objective To explore the clinical characteristic and occcurrence rule of silent myocardial ischemia(SMI)in aged patients with coronary heart disease(CHD).Methods 24-hour dynamic electrocardiogram monitoring was performed in 74 CHD patients.The 74 patients were divided into 3 groups;group I:pure SMI;gronp Ⅱ:patients with angina pectoris;group Ⅲ:SMI patients after myocardial infarction.Results Myocardial ischemia was found to occur 634 times.The frequency of occurrence of SMI(90.22%) was obviously higher than those of symptomatic ischemia.The frequency of SMI was highest between 6 a.m.to 12 a.m.From group Ⅰ to group Ⅱ and to group Ⅲ,the frequency and duration of episodes of SMI and the grade of ST segment depression increased gradually.The grade of myocardial ischemia had positive correlation with the state of illness,while negative correlation with the heart rate variability(HRV).The frequency of SMI was lowest between 0 a.m.to 6 a.m. but serious than those occuxred on day time.Conclusion SMI is the most common manifestation in patients with CHD.It should be paid the same enough attention as the symptomatic.The impairment of cardiac autonomic nerves is associated with the extension of ischemia in patients with CHD.