Electrocardiogram and echocardiogram changes of healthy youngsters during high altitude de-adaptation
Objective To explore the changing patterns of electrocardiogram(ECG)and echocardiography in healthy young people during their descent from high altitude to the plain.Methods A prospective cohort study was carried out.Fifty-five healthy young volunteers who had migrated to an altitude of 4800-5500 m on the Qinghai-Tibet Plateau within one year were recruited as the plateau-migration group.ECG examinations were performed at an altitude of 3700 m(first time),on the 5th day after returning to 1300 m(second time),and on the 15th day after returning to 1300 m(third time).Echocardiography was conducted at 3700 m and on the 5th day after returning to 1300 m.A plain control group of 55 healthy youngsters from the plains(1300 m)was matched.The results of ECG and echocardiography between the two groups were compared.Results Intragroup analysis of the plateau-migration group revealed that compared with the first ECG results,the number of normal ECGs decreased in the second and third ECG results(P<0.05),and the proportions of sinus rhythm irregularity,sinus bradycardia,and U-wave appearance increased(P<0.05).There was no statistically significant difference in abnormal ECG results between the second and third ECGs(P>0.05).Compared with plain control group,there was no significant difference in the abnormal results of the first ECG of plateau-migration group(P>0.05).In the second and third ECG results,the number of normal ECGs was significantly reduced,and the proportions of sinus bradycardia,sinus rhythm irregularity,and U-wave appearance were significantly increased compared with plain control group(P<0.001).Intragroup analysis of plateau-migration group revealed that compared with the first ECG,the heart rate decreased in the second and third ECGs(P<0.05 or<0.001).Compared with plain control group,in the first ECG of plateau-migration group,the PR interval was significantly prolonged,the QTc interval was shortened,and the QRS axis degree was increased(P<0.05).In the second ECG,the heart rate significantly decreased,the PR interval was prolonged,and the QTc interval was shortened(P<0.05).In the third ECG,the heart rate decreased,the PR interval was prolonged,the QTc interval was shortened,and the QRS axis degrees was increased(P<0.05).The QRS axis of the first,second,and third ECGs of plateau-migration group was statistically significantly different from that of plain control group(P<0.001).Intragroup analysis of plateau-migration group showed that compared with the first echocardiogram,the left ventricular end-systole diameter,left ventricular end-diastolic diameter,and left atrial anteroposterior diameter all significantly increased in the second echocardiogram(P<0.001).Compared with plain control group,in the first echocardiogram of plateau-migration group,the left ventricular end-systole diameter and right atrial transection diameter significantly decreased,the right ventricular transection diameter significantly increased,and the left ventricular fractional shortening rate(FS)significantly decreased(P<0.05);In the second echocardiogram,the left atrial anteroposterior diameter,right atrial transverse diameter,and right ventricular transverse diameter all significantly increased,and FS increased(P<0.05).Conclusions In healthy young people returning from high altitude to the plain,as the altitude decreased,the heart rate significantly drops.The number of people with frontal QRS axis right deviation significantly reduces.The number of normal ECGs significantly decreases,while the numbers of people with sinus bradycardia,sinus arrhythmias,and U-wave appearance significantly increase.During high-altitude stay,the left ventricular systolic and diastolic function is affected to some extent.
de-adaptation to high altitudeplateauplainelectrocardiogramechocardiogram
国家科技期刊平台
NSTL
万方数据
