Sheehan F H, Stewart D K, Dodge H T, Mitten S, Bolson E L, Brown B G
Circulation. 1983 Sep;68(3):550-9. doi: 10.1161/01.cir.68.3.550.
Four types of variability affecting quantification of regional wall motion from contrast left ventriculograms (LVgrams) were studied. These included beat-to-beat variability in 24 LVgrams, intraobserver and interobserver variability in 20 LVgrams, and study-to-study variability in serial LVgrams of 21 patients with stable coronary artery disease. Motion was measured at 100 equidistant chords perpendicular to a center line drawn midway between the end-diastolic and end-systolic contours and normalized for heart size. Variability was computed as the absolute difference between observations. Beat-to-beat, intraobserver, and interobserver variability at the 100 chords were similar, averaging 14%, 14%, and 17%, respectively, of the mean motion in 64 patients with normal ventriculograms. Study-to-study variability was significantly higher, averaging 30% of mean normal motion, but was reduced when regional motion was calculated as the mean motion of chords within a region of interest. Variability peaked at the apex. Realignment to correct for cardiac rotation significantly increased variability. Investigators whose methods of wall motion analysis rely on identification of the apex as a landmark should be aware of this source of potential variability and error.
研究了影响从对比左心室造影（LVgram）定量分析局部室壁运动的四种变异性类型。这些包括24例LVgram中的逐搏变异性、20例LVgram中的观察者内和观察者间变异性，以及21例稳定型冠状动脉疾病患者的系列LVgram中的研究间变异性。在垂直于舒张末期和收缩末期轮廓之间中点绘制的中心线的100条等距弦上测量运动，并根据心脏大小进行归一化。变异性计算为观测值之间的绝对差值。在64例心室造影正常的患者中，100条弦处的逐搏、观察者内和观察者间变异性相似，平均分别为平均运动的14%、14%和17%。研究间变异性显著更高，平均为正常平均运动的30%，但当将局部运动计算为感兴趣区域内弦的平均运动时，变异性会降低。变异性在 apex 处达到峰值。为校正心脏旋转而进行的重新对齐显著增加了变异性。那些壁运动分析方法依赖于将 apex 识别为标志的研究者应该意识到这种潜在变异性和误差的来源。
