Dubrey S W, Falk R H
Section of Cardiology, Boston University School of Medicine, MA, USA.
J Am Soc Echocardiogr. 1997 Jan-Feb;10(1):67-71. doi: 10.1016/s0894-7317(97)80034-x.
This study was undertaken to determine the optimum number of Doppler velocity waveforms required to calculate cardiac output in atrial fibrillation with the same degree of accuracy as that for sinus rhythm. Twenty-one patients in atrial fibrillation underwent calculations of cardiac output derived from aortic Doppler waveform velocity time integrals and RR intervals. The variability in estimates of the cardiac output was calculated with the successive addition of sequential beats and compared with that determined in a control group of 12 subjects in sinus rhythm. For the group in atrial fibrillation, a mean of 13 beats (range 4 to 17 beats) was required to achieve an estimation of cardiac output with a variability of less than 2%, compared with a mean of four beats in sinus rhythm. In atrial fibrillation, the mean number of beats required to determine cardiac output was approximately three times that necessary in sinus rhythm.
本研究旨在确定在心房颤动中计算心输出量所需的最佳多普勒速度波形数量，以达到与窦性心律相同的准确程度。21例心房颤动患者通过主动脉多普勒波形速度时间积分和RR间期进行心输出量计算。随着连续心跳的逐次增加，计算心输出量估计值的变异性，并与12例窦性心律对照组受试者的变异性进行比较。对于心房颤动组，平均需要13次心跳（范围为4至17次心跳）才能实现心输出量估计，其变异性小于2%，而窦性心律组平均需要4次心跳。在心房颤动中，确定心输出量所需的平均心跳次数约为窦性心律时所需次数的三倍。
