Division of Cardiac Anesthesia, Department of Anesthesiology and Critical Care Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
Department of Anesthesiology and Reanimatology, University of Fukui, Fukui, Japan.
Hypertens Res. 2017 Sep;40(9):811-818. doi: 10.1038/hr.2017.43. Epub 2017 Mar 30.
The left ventricular ejection time is routinely measured from a peripheral arterial waveform. However, the arterial waveform undergoes constant transformation as the pulse wave propagates along the arterial tree. Our goal was to determine if the left ventricular ejection time measured peripherally in the arterial tree accurately reflected the ejection time measured through the aortic valve. Moreover, we examined/accessed the modulating influence of hemodynamics on ejection time measurements. Continuous wave Doppler waveform images through the aortic valve and the simultaneously obtained radial artery pressure waveforms were analyzed to determine central and peripheral ejection times, respectively. The peripheral ejection time was significantly longer than the simultaneously measured central ejection time (174.5±25.2 ms vs. 120.7±14.4 ms; P<0.0001; 17.4±8.7% increase). Moreover, the ejection time prolongation was accentuated at lower blood pressures, lower heart rate and lower pulse wave velocity. The time difference between centrally and peripherally measured ejection times likely reflects intrinsic vascular characteristics. Moreover, given that the ejection time also depends on blood pressure, heart rate and pulse wave velocity, peripherally measured ejection times might need to be adjusted to account for changes in these variables.
左心室射血时间通常可通过外周动脉波形来测量。然而，随着脉搏波沿动脉树传播，动脉波形会不断发生变化。我们的目标是确定在动脉树的外周测量的左心室射血时间是否能准确反映通过主动脉瓣测量的射血时间。此外，我们还研究了/探讨了血流动力学对射血时间测量的调节影响。通过主动脉瓣获得连续波多普勒波形图像，并同时分析获得的桡动脉压力波形，分别确定中央和外周射血时间。外周射血时间明显长于同时测量的中央射血时间（174.5±25.2ms 比 120.7±14.4ms；P<0.0001；增加 17.4±8.7%）。此外，在较低的血压、较低的心率和较低的脉搏波速度下，射血时间延长更为明显。中央和外周测量的射血时间之间的差异可能反映了内在的血管特征。此外，由于射血时间还取决于血压、心率和脉搏波速度，因此外周测量的射血时间可能需要进行调整以考虑这些变量的变化。
