Abstract：Objective To explore the characteristics of aging changes in 24hour ambulatory electrocardiogram (AECG) of elderly patients. Methods The data of 12lead 24hour AECG from our hospital were retrospective analyzed, and the following conditions were required:① Local resident; ② The age of the patient is no less than 60 when taken first AECG; ③The same patient should take at least two AECG examinations, with an interval of at least 5 years between the first and the last examination; ④ No cardiac pacemaker implantation; ⑤ There is a complete life log, including work and rest time, daily activities, and when symptoms start and end, etc. A total of 98 patients were enrolled. The hospitalized medical records of the patients were reviewed, and the standard was developed. The 24hour mean heart rate, slowest heart rate, fastest heart rate, arrhythmia and ST segment ischemic attack detected by AECG were analyzed and compared between the two AECGs. Results With the increase of age, the 24hour mean heart rate, the slowest heart rate and the fastest heart rate of 98 elderly patients all showed a tendency of slowing down with statistical difference (P<0.001). All kinds of arrhythmias showed an increasing trend, among which the case of ventricular premature with Lown grade≥ Ⅲ increased from 0 to 10 cases, while the case of arrhythmias contained 3 or more types increased from 18 (18.37%) to 67(68.37%) (P<0.001). Twentyeight cases (125 times) of ST segment ischemic depression were detected in the first examination, including 82 times of silent myocardial ischemia (SMI), 43 times of symptomatic myocardial ischemia. Sixty cases (272 times) of ST segment ischemic depression were detected in the last examination, including 214 times of SMI and 58 times of symptomatic myocardial ischemia. The number of both SMI and symptomatic myocardial ischemic ST segment ischemic depression increased with age, and SMI increased significantly (P<0.001). All the patients showed a circadian rhythm of ST segment ischemic depression, but this circadian rhythm was weakened with the age growth, especially for SMI (P=0.535). Conclusions The elderly patients showed significant agerelated changes in 24hour AECG, and regular AECG examination is of great value.
