Cotrim Carlos, Almeida Ana G, Carrageta Manuel
Serviço de Cardiologia, do Hospital Garcia de Orta, Almada, Portugal.
Rev Port Cardiol. 2008 Nov;27(11):1367-75.
The development of intraventricular gradients on exertion has been described in various clinical settings. Recently, a small study using exercise echocardiography in healthy subjects, with image acquisition immediately after exercise termination, failed to demonstrate the development of intraventricular gradients. In the present study, we performed exercise echocardiography in 34 healthy individuals, mean age 50 +/- 12 years (age range, 28 to 70), 17 of whom were male. The development of obstructive intraventricular gradients and systolic anterior motion (SAM) of the mitral valve during exertion was evaluated using Doppler echocardiography during exercise treadmill testing according to the Bruce protocol. Exercise testing had a mean duration of 653 +/- 144 sec and a mean of 92 +/- 8% of age-predicted maximum heart rate was attained. The mean double product achieved at peak exercise was 25,703 +/- 2887. Maximum left ventricular outflow tract velocity measured using continuous-wave Doppler and in left lateral decubitus was significantly different from that obtained in the orthostatic position (125 +/- 16.3 vs. 111 +/- 13.9 cm/sec, p<0.000). Maximum left ventricular outflow tract velocity at three minutes of exercise was also significantly different from that obtained in the resting orthostatic position (163 +/- 29 vs. 111 +/- 13.9 cm/sec, p<0.000). Maximum left ventricular outflow tract velocity at peak exercise was also higher than that obtained at three minutes of exercise (199.9 +/- 23 vs. 163 +/- 29 cm/sec, p<0.000). The maximum velocity measured at peak exercise in the study population was 237 cm/sec. None of the patients in this study demonstrated a pattern of intraventricular flow with endsystolic peak velocity consistent with the development of an intraventricular gradient. Similarly, none of the patients developed SAM of the mitral valve during exercise. We concluded that, in the present study, a group of healthy subjects did not develop left intraventricular gradients or SAM during exertion.
在各种临床情况下均已描述了运动时心室内压力阶差的发展情况。最近，一项针对健康受试者的小型研究，在运动结束后立即进行图像采集，使用运动超声心动图未能证实心室内压力阶差的发展。在本研究中，我们对34名健康个体进行了运动超声心动图检查，这些个体的平均年龄为50±12岁（年龄范围为28至70岁），其中17名为男性。根据布鲁斯方案，在运动平板试验期间使用多普勒超声心动图评估运动时梗阻性心室内压力阶差和二尖瓣收缩期前向运动（SAM）的发展情况。运动试验的平均持续时间为653±144秒，平均达到年龄预测最大心率的92±8%。运动高峰时达到的平均双乘积为25,703±2887。使用连续波多普勒在左侧卧位测量的最大左心室流出道速度与直立位时显著不同（125±16.3对111±13.9 cm/秒，p<0.000）。运动3分钟时的最大左心室流出道速度也与静息直立位时显著不同（163±29对111±13.9 cm/秒，p<0.000）。运动高峰时的最大左心室流出道速度也高于运动3分钟时（199.9±23对163±29 cm/秒，p<0.000）。研究人群中运动高峰时测量的最大速度为237 cm/秒。本研究中没有患者表现出与心室内压力阶差发展一致的收缩末期峰值速度的心室内血流模式。同样，没有患者在运动期间出现二尖瓣SAM。我们得出结论，在本研究中，一组健康受试者在运动时未出现左心室内压力阶差或SAM。
