Hoit B D, Rashwan M, Watt C, Sahn D J, Bhargava V
Division of Cardiology, Veterans Administration Medical Center, San Diego, California.
Am J Cardiol. 1988 Jul 1;62(1):131-5. doi: 10.1016/0002-9149(88)91378-1.
To simplify transmitral volume flow determination by Doppler echocardiography, a formula for calculating mean mitral valve orifice area using M-mode echocardiography without any 2-dimensional measurements was developed and evaluated in this study. The maximal mitral orifice area was assumed to be circular and its diameter was calculated from the maximal M-mode mitral leaflet separation. The maximal area was multiplied by the mean to maximal anterior mitral leaflet excursion ratio to correct for phasic changes in flow orifice area during ventricular filling. This measurement had a high correlation (r = 0.97, standard error of the estimate + 0.26 cm2) with mean mitral valve orifice area calculated from frame-by-frame analysis of short-axis 2-dimensional echoes in a select group of 10 normal volunteers and 10 patients with cardiomyopathy who had very high quality images of the mitral valve leaflet tips. Cardiac output calculated using the new method for orifice area estimation combined with apex view mitral valve Doppler velocities was then validated in 48 consecutive patients undergoing thermodilution cardiac output determinations with a close correlation between Doppler and thermodilution cardiac output (2.3 to 6.1 liter/min, r = 0.93, standard error of the estimate = 362 ml). The correlation improved when 12 patients with mild mitral insufficiency were excluded (r = 0.95). The M-mode echocardiogram-derived mitral valve orifice method combined with Doppler mitral valve velocities is accurate, easy to perform, has a high success rate and should increase the applicability of Doppler echocardiography for estimation of cardiac output.
为简化经多普勒超声心动图测定二尖瓣血流量，本研究开发并评估了一种无需任何二维测量、使用M型超声心动图计算平均二尖瓣口面积的公式。假定最大二尖瓣口面积为圆形，其直径根据M型二尖瓣叶最大分离度计算得出。将最大面积乘以平均至二尖瓣前叶最大运动幅度之比，以校正心室充盈期间血流口面积的相位变化。在一组10名正常志愿者和10名患有心肌病且二尖瓣叶尖部图像质量非常高的患者中，该测量值与通过短轴二维回波逐帧分析计算出的平均二尖瓣口面积具有高度相关性（r = 0.97，估计标准误差±0.26 cm²）。然后，在48例连续接受热稀释法心输出量测定的患者中，验证了使用新的口面积估计方法结合心尖视图二尖瓣多普勒速度计算的心输出量，多普勒心输出量与热稀释法心输出量之间具有密切相关性（2.3至6.1升/分钟，r = 0.93，估计标准误差 = 362毫升）。排除12例轻度二尖瓣反流患者后，相关性有所改善（r = 0.95）。M型超声心动图衍生的二尖瓣口方法结合多普勒二尖瓣速度准确、易于操作、成功率高，应能提高多普勒超声心动图在心输出量估计中的适用性。
