Shapiro L M, Thwaites B C
National Heart Hospital, London.
Cardiovasc Res. 1987 Jul;21(7):489-91. doi: 10.1093/cvr/21.7.489.
The relation between mitral valve opening and transmitral blood flow was investigated by M-mode echocardiography and Doppler ultrasound in 50 normal subjects to allow the measurement of the timing of the end of isovolumic relaxation. Standard parasternal M-mode echocardiograms of the mitral valve to show the onset of cusp separation were recorded with a simultaneous electrocardiogram and phonocardiogram. Pulse wave Doppler ultrasound using both amplitude and spectral analysis was recorded with a transducer at the apex, and the initial diastolic blood flow towards the transducer was taken as the onset of flow. For each subject five cardiac cycles of similar length were measured using the three methods. Isovolumic relaxation could be measured with a high degree of reliability (retest reliability coefficient greater than 0.94). The echocardiographic measurement of isovolumic relaxation ranged from 52 to 82 ms (mean(SD) 67(9) ms). Isovolumic relaxation measured by Doppler was 52-83 ms (mean(SD) 67(9) ms) using amplitude analysis and 54-89 ms (mean(SD) 72(11) ms) using spectral analysis. There was a strong correlation between the echocardiographic isovolumic relaxation and measurements made using spectral analysis (r = 0.93, slope 0.97) and amplitude analysis (r = 0.97, slope 0.98). Therefore in normal subjects the end of isovolumic relaxation can be reliably measured by echocardiographic and Doppler methods, and whereas the amplitude signal is coincidental with that measured by echocardiography that measured by spectral analysis is delayed by approximately 5 ms.
采用M型超声心动图和多普勒超声对50名正常受试者的二尖瓣开放与跨二尖瓣血流之间的关系进行了研究，以测定等容舒张期末的时间。记录标准胸骨旁二尖瓣M型超声心动图，以显示瓣叶分离的起始，并同步记录心电图和心音图。使用位于心尖的换能器记录采用幅度和频谱分析的脉冲波多普勒超声，朝向换能器的初始舒张期血流被视为血流起始。对每名受试者使用这三种方法测量了五个长度相似的心动周期。等容舒张期能够以高度可靠性进行测量（重测可靠性系数大于0.94）。等容舒张期的超声心动图测量值范围为52至82毫秒（均值（标准差）67（9）毫秒）。采用幅度分析时，多普勒测量的等容舒张期为52 - 83毫秒（均值（标准差）67（9）毫秒），采用频谱分析时为54 - 89毫秒（均值（标准差）72（11）毫秒）。超声心动图测量的等容舒张期与采用频谱分析（r = 0.93，斜率0.97）和幅度分析（r = 0.97，斜率0.98）所做的测量之间存在很强的相关性。因此，在正常受试者中，等容舒张期末可通过超声心动图和多普勒方法可靠地测量，并且幅度信号与超声心动图测量的信号一致，而频谱分析测量的信号延迟约5毫秒。
