Methods The color Doppler data including intraventricular pressure gradients(IVPG) and color singular value(CSV) were collected with the two-dimensional color Doppler image analyzing system.

• 方法使用自制左室流入彩色多普勒图像分析系统,自动计算舒张早期沿左室流入彩色多普勒血流的色阶差数据,计算左室流入血流的平均压力阶差(IVPG)与彩色血流色阶奇异值(color singularvalue,CSV)。