Hadjis T, Jobin J, Bourbeau J, Desagagnés P, Juneau L, Sampalis J
Service de pneumologie, Hôpital du Saint-Sacrement, Montreal, Québec.
Can J Cardiol. 1995 Feb;11(2):100-4.
To determine the intra- and interobserver reproducibility of Doppler-derived ascending aortic flow velocity measurements at rest and during upright exercise of increasing intensity; and to determine the relationship between Doppler-derived measurements and cardiac output obtained by the indirect Fick carbon dioxide rebreathing method in the same conditions.
Twenty young healthy adults participated in the study; eight participated in the first part and 12 in the second.
For the intra-observer study, subjects were submitted to three workloads (50, 100 and 150 W) of 5 mins duration on two occasions, seven days apart. The intra-observer reproducibility was determined by two technicians taking the Doppler measurements within 90 s during the steady state of each workload during the first session. The relationship between cardiac output and aortic flow velocities was studied by measuring cardiac output by carbon dioxide rebreathing and flow velocities by continuous wave Doppler ultrasound simultaneously at rest as well as during the last minute of the three workloads (50, 100 and 150 W) of 5 mins duration.
The interobserver reproducibility was very good, with r values of 0.87 for peak velocity (PV) and 0.97 for peak acceleration (PA). The intra-observer reproducibility at the seventh day interval showed r values of 0.93 for PV and 0.96 for PA for one of the technicians. PV and PA of the ascending aortic flow correlated well with cardiac output (r = 0.85 and 0.82, respectively, P < 0.01). ANOVA showed that PV and PA increase proportionately with exercise intensity.
PV and PA of ascending aortic flow are reproducible and reflect changes in left ventricular function during exercise.
确定在静息状态及强度递增的直立运动过程中，多普勒测量升主动脉血流速度的观察者内及观察者间的可重复性；并确定在相同条件下，多普勒测量值与通过间接菲克二氧化碳重呼吸法获得的心输出量之间的关系。
20名年轻健康成年人参与了该研究；其中8人参与了第一部分，12人参与了第二部分。
在观察者内研究中，让受试者在两次分别相隔7天的情况下，接受三种持续5分钟的工作量（50瓦、100瓦和150瓦）。观察者内可重复性由两名技术人员在第一次测试中每个工作量的稳定状态下90秒内进行多普勒测量来确定。通过在静息状态以及三种持续5分钟的工作量（50瓦、100瓦和150瓦）的最后一分钟，同时用二氧化碳重呼吸法测量心输出量并用连续波多普勒超声测量血流速度，来研究心输出量与主动脉血流速度之间的关系。
观察者间的可重复性非常好，峰值速度（PV）的r值为0.87，峰值加速度（PA）的r值为0.97。对于其中一名技术人员，在间隔7天的观察者内可重复性显示，PV的r值为0.93，PA的r值为0.96。升主动脉血流的PV和PA与心输出量相关性良好（r分别为0.85和0.82，P<0.01）。方差分析表明，PV和PA随运动强度成比例增加。
升主动脉血流的PV和PA具有可重复性，并反映运动过程中左心室功能的变化。
