Sandor G G, Webber S A, Popov R O, DeSouza E, Johnston B
Department of Paediatrics, University of British Columbia, Vancouver, Canada.
J Am Soc Echocardiogr. 1996 May-Jun;9(3):251-6. doi: 10.1016/s0894-7317(96)90137-6.
This study determined the short- and long-term variability of stress-velocity relationships at end systole and peak systole. A prospective study during the short term (0 to 15 and 0 to 30 minutes) and long term (0 to 1 and 0 to 12 months) was performed calculating variability by the limits of agreement method. The study was performed in a tertiary-care pediatric echocardiographic laboratory. Twenty-five normal children underwent repeat testing as described. Standard blood pressure, carotid pulse tracing, and M-echocardiography of the left ventricle was performed at the intervals described. The rate-corrected mean velocity of fiber shortening (MVCFC), echocardiographic stress at end systole (SES), and echocardiographic stress at peak systole (SPS) were calculated for all recordings. The slopes of MVCFC-SES and MVCFC-SPS were determined by regression and plotted. With these slopes, the second and third stress values were normalized to the first stress value for the short and long term. The differences in normalized MVCFC and MVCFC (delta MVCFC) for 15 to 0 minutes, 30 to 0 months, 1 to 0 month, and 12 to 1 month were obtained for both SES and SPS, and 95% limits of agreement were estimated. The mean delta MVCFC for SES and SPS for the short and long term were not different from 0 or each other, indicating no bias. The 95% limits of agreement of delta MVCFCs (i.e., variability for SES at 15 to 0 minutes, 30 to 0 minutes, 1 to 0 month, and 12 to 0 month) were +/- 0.18, +/- 0.24, +/- 0.34, and +/- 0.27, respectively, and for SPS +/- 0.18, +/- 0.24, +/- 0.33, and +/- 0.28. Variability showed an increasing trend with time but was significant only from 15 to 0 minutes and 1 to 0 month (p = 0.006). This study has established short- and long-term variability in the stress-velocity relationship that is essential for monitoring acute and chronic changes in ventricular contractility in an individual patient.
本研究确定了收缩末期和收缩峰值时应力-速度关系的短期和长期变异性。采用一致性界限法计算变异性，进行了短期（0至15分钟和0至30分钟）和长期（0至1个月和0至12个月）的前瞻性研究。研究在一家三级护理儿科超声心动图实验室进行。25名正常儿童按所述方法接受重复检测。按照所述间隔进行标准血压、颈动脉脉搏描记以及左心室M型超声心动图检查。计算所有记录的心率校正平均纤维缩短速度（MVCFC）、收缩末期超声心动图应力（SES）和收缩峰值超声心动图应力（SPS）。通过回归确定MVCFC-SES和MVCFC-SPS的斜率并绘图。利用这些斜率，将短期和长期的第二个和第三个应力值相对于第一个应力值进行标准化。获取了SES和SPS在15至0分钟、30至0个月、1至0个月以及12至1个月时标准化MVCFC与MVCFC的差值（δMVCFC），并估计了95%一致性界限。SES和SPS短期和长期的平均δMVCFC与0无差异，且彼此之间也无差异，表明无偏差。δMVCFC的95%一致性界限（即15至0分钟、30至0分钟、1至0个月以及12至0个月时SES的变异性）分别为±0.18、±0.24、±0.34和±0.27，SPS的分别为±0.18、±0.24、±0.33和±0.28。变异性随时间呈增加趋势，但仅在15至0分钟和1至0个月时具有显著性（p = 0.006）。本研究确立了应力-速度关系的短期和长期变异性，这对于监测个体患者心室收缩性的急性和慢性变化至关重要。
