摘要目的 比较老年人与中青年人群心肌梗死发病时间的差异，以指导临床防治。方法 选取2000年1月至2010年5月我院确诊为急性ST段抬高心肌梗死且症状发作时间明确的1024例患者。根据年龄分为中青年组（＜65岁）536例，老年组（≥65岁）488例，比较两组发病月、周、日的差异。结果 中青年组心肌梗死发病人数在10月及2月，周五、周六及周三，早上10点及晚上10点较高。老年组心肌梗死发病人数在10月、1月及3月，周五、周日及周一，早上6点及2点较高。老年组在3月(11.89％)，周日(15.97％)及周一(17.42％)，早6点(6.35％)及2点(5.74％)心肌梗死发病高于中青年组(P＜0.05)。中青年组在2月(9.89％)，周六(16.98％)，晚8点(4.86％)及晚10点(5.78％)心肌梗死发病高于老年组(P＜0.05)。结论 老年人心肌梗死发病时间规律不同于中青年，易发在季节交替、休息日与工作日交替及凌晨。提示心肌梗死发病时间规律在不同年龄段有所差异。

abstractsObjective To compare the differences on onset timing of acute ST segment elevation myocardial infarction (STEMI) in young and aged patients. Methods The exact onset time of symptoms was obtained from 1024 consecutive patients with STEMI admitted to our hospital between January 2000 and May 2010. Patients were classified as the middle-aged group [＜65 years old, mean (52.2 ±8.0)years, n =536]and old group [≥65 years old, (72. 2 ±5.5)years, n =488], the difference of the onset months,weeks, weekdays and hours between two groups was compared. Results The high onset timing of STEMI in middle-aged group was October and February, Friday, Saturday and Wednesday, at 10 A.m. And 10P. M. The high onset timing of STEMI in old group was October, January and March, Friday, Sunday and Monday, at 6 A.m. And 2 A. M. The incidences of STEMI in the old group were significant higher than in the middle-aged group in March ( 11.89％ ), on Sunday ( 15.97％ ) and Monday ( 17.42％ ), at 6 A.m.(6.35％)and 2 A. M. (5.74％) (all P ＜0.05) while the onset rate was significant higher in February (9. 89％ ), On Saturday16. 98％ ), At 8 P. M. (4. 86％ )and 10 P. M. (5.78％)in the middle-aged group than old group ( all P ＜ 0. 05 ). Conclusion The onset timing of STEMI in old patients was significant different from the middle-aged patients suggesting the onset timing of STEMI changes with aging.