Effects of long voyage on crew's cardiac function evaluated by high definition impedance cardiography
Objective To evaluate the effects of long voyage on crew's cardiac function.Methods A total of 47 crew members from a shipyard during the maintenance period of two ships with the same type from October 2017 to April 2018 were selected as research subjects.They were divided into experimental group(n=24)and control group(n=23).The first test was performed in all subjects within 5 days of enrollment.The experimental group participated in a 34-day seagoing voyage after the first test,while the control group continued to live on land and do regular physical exercise.All the subjects were tested again within 5 days after sailing.The submaximal exercise test was conducted according to the standard Bruce protocol.High definition impedance cardiogram was synchronously used to record heart rate and stroke output(SV)at rest.SV was continuously recorded to obtain its maximum value(SVmax)and the change of SV during exercise was analyzed.The exercise time,SV threshold,and SV threshold time were also recorded.Results There were no significant differences in the age,height,or weights at the beginning or end of the study between the two groups(P>0.05).At the end of the study,the exercise time of the experimental group was significantly shorter than that of the control group and the control group was prolonged(P<0.01).There was no significant difference in the SV threshold time,HR at rest,average resting SV,or SVmax between the two groups at enrollment(P>0.05).The SV threshold time at the end of the study was significantly shorter than that at enrollment in the experimental group,and there was a significant difference in the SV threshold time at the end of the study between the two groups(P<0.01).At the end of the study,the resting HR of the experimental group was significantly higher than that at enrollment and that of the control group(P<0.05);there were significant differences in the mean SV at rest and SVmax between groups and between intra-groups(P<0.05).Conclusion Long voyage can reduce the aerobic capacity and cardiac reserve of crew,and the preservation of aerobic exercise can improve the cardiac function and cardiac reserve.
Long voyageImpedance cardiographyCardiac functionTreadmill exercise testing
NETL
NSTL
万方数据
