De Hert S G, Rodrigus I E, Haenen L R, De Mulder P A, Gillebert T C
Department of Anesthesiology, University of Antwerp, Belgium.
Anesthesiology. 1996 Nov;85(5):1063-75. doi: 10.1097/00000542-199611000-00015.
Impairment of left ventricular function after cardiopulmonary bypass (CPB) is well recognized, but little is known about the time course of recovery of cardiac function early after separation from CPB. Therefore, recovery of left ventricular function was evaluated early after separation from CPB in patients undergoing coronary artery surgery. The authors tried to determine whether this recovery might be attributed to autoregulation of function by preload.
Left ventricular pressure was measured with fluid-filled catheters. Data were digitally recorded during increased pressure induced by elevating the legs. Transgastric short-axis echocardiographic views of the left ventricle were simultaneously recorded on videotape. Systolic function was evaluated with the slope (Ees, mmHg/ml) of the systolic pressure-volume relation. Diastolic function was evaluated with the chamber stiffness constant (Kc, ml-1) of the diastolic pressure-volume relation. Cardiac function was assessed before CPB, after termination of CPB, and 5, 10, and 15 min later. Two different separation procedures from CPB were compared: in protocol 1, left ventricular function was documented during the standard procedure (n = 24); in protocol 2, the heart was optimally filled 10 min before separation from CPB (n = 12).
In protocol 1, Ees was 2.88 +/- 0.21 mmHg/ml (mean +/- SEM) and Kc was 0.012 +/- 0.001 ml-1 before CPB. Within 10 min after separation from CPB, Ees increased from 1.10 +/- 0.32 to 2.92 +/- 0.34 (P = 0.001) and Kc decreased from 0.022 +/- 0.002 to 0.011 +/- 0.001 (P = 0.001). The parameters remained stable thereafter. In protocol 2, Ees was 2.92 +/- 0.51 mmHg/ ml and Kc was 0.011 +/- 0.002 ml-1 before CPB. Depression of systolic and diastolic function was not observed in these patients. At time 0, Ees was 2.46 +/- 0.16 and Kc was 0.012 +/- 0.002. These values remained stable throughout the entire observation period.
Significant functional recovery was observed early after separation from CPB, which was suggestive of time-dependent changes in both systolic and diastolic left ventricular function induced by preload restoration.
体外循环（CPB）后左心室功能受损已得到充分认识，但对于CPB结束后早期心脏功能恢复的时间进程了解甚少。因此，对接受冠状动脉手术的患者在CPB结束后早期的左心室功能恢复情况进行了评估。作者试图确定这种恢复是否可能归因于前负荷对功能的自动调节。
使用充满液体的导管测量左心室压力。在抬高腿部引起压力升高期间对数据进行数字记录。同时在录像带上记录经胃左心室短轴超声心动图图像。用收缩压-容积关系的斜率（Ees，mmHg/ml）评估收缩功能。用舒张压-容积关系的心室僵硬度常数（Kc，ml-1）评估舒张功能。在CPB前、CPB结束后以及之后5、10和15分钟评估心脏功能。比较了两种不同的CPB脱离程序：在方案1中，在标准程序期间记录左心室功能（n = 24）；在方案2中，在脱离CPB前10分钟将心脏最佳充盈（n = 12）。
在方案1中，CPB前Ees为2.88±0.21 mmHg/ml（均值±标准误），Kc为0.012±0.001 ml-1。在脱离CPB后10分钟内，Ees从1.10±0.32升高至2.92±0.34（P = 0.001），Kc从0.022±0.002降至0.011±0.001（P = 0.001）。此后参数保持稳定。在方案2中，CPB前Ees为2.92±0.51 mmHg/ml，Kc为0.011±0.002 ml-1。在这些患者中未观察到收缩和舒张功能的降低。在时间0时，Ees为2.46±0.16，Kc为0.012±0.002。这些值在整个观察期内保持稳定。
在脱离CPB后早期观察到显著的功能恢复，这提示前负荷恢复引起左心室收缩和舒张功能随时间的变化。
