Mitchell G D, Brunken R C, Schwaiger M, Donohue B C, Krivokapich J, Child J S
Department of Medicine, UCLA School of Medicine.
Am J Cardiol. 1988 Mar 1;61(8):536-40. doi: 10.1016/0002-9149(88)90760-6.
Exercise-induced myocardial ischemia results in both diastolic and systolic left ventricular (LV) dysfunction. To investigate the utility of Doppler assessment of LV diastolic function with exercise, 28 consecutive patients underwent digital stress echocardiography, including measurement of mitral flow velocity by pulsed-wave Doppler and simultaneous stress thallium imaging. The mean mitral flow velocity was measured as the integrated area under the LV diastolic inflow Doppler spectral display. The change in mean mitral flow velocity from baseline to immediate postexercise was compared among 3 patient groups: (1) patients with thallium redistribution or exercise-induced wall-motion abnormalities, or both, consistent with exercise-induced ischemia (n = 18), (2) patients with no evidence of stress-induced ischemia, with or without resting wall-motion abnormalities (n = 10), and (3) 10 control subjects of similar age with normal resting 12-lead electrocardiograms, normal resting and postexercise 2-dimensional echocardiograms and normal electrocardiographic treadmill stress testing. The percent increase in mean mitral flow velocity was 101% (+/- 59) for controls and 86% (+/- 53) for patients without stress-induced ischemia versus 33% (+/- 24) in patients with stress-induced ischemia (p less than 0.005). An increase in mean mitral flow velocity with exercise of greater than 50% correctly identified 9 of 10 nonischemic control patients. An increase in mean velocity of less than 50% predicted ischemia in 15 of 18 patients with evidence of stress-induced ischemia (p less than 0.005) Thus, Doppler assessment of LV diastolic function with exercise expressed as a change in the mean velocity of mitral flow is a useful indicator of stress-induced ischemia.
运动诱发的心肌缺血会导致左心室（LV）舒张功能和收缩功能障碍。为了研究运动时多普勒评估左心室舒张功能的效用，连续28例患者接受了数字负荷超声心动图检查，包括用脉冲波多普勒测量二尖瓣血流速度以及同步进行负荷铊显像。平均二尖瓣血流速度通过左心室舒张期流入多普勒频谱显示下的积分面积来测量。比较了3组患者从基线到运动后即刻平均二尖瓣血流速度的变化：（1）铊再分布或运动诱发的室壁运动异常或两者皆有，与运动诱发的缺血相符的患者（n = 18），（2）无应激诱发缺血证据、有或无静息室壁运动异常的患者（n = 10），以及（3）10名年龄相仿、静息12导联心电图正常、静息和运动后二维超声心动图正常且心电图平板运动试验正常的对照受试者。对照组平均二尖瓣血流速度增加百分比为101%（±59），无应激诱发缺血的患者为86%（±53），而应激诱发缺血的患者为33%（±24）（p<0.005）。运动时平均二尖瓣血流速度增加超过50%可正确识别10名非缺血对照患者中的9名。平均速度增加小于50%可预测18名有应激诱发缺血证据患者中的15名存在缺血（p<0.005）。因此，以二尖瓣血流平均速度变化表示的运动时左心室舒张功能的多普勒评估是应激诱发缺血的有用指标。
