Leung J M, Levine E H
Department of Anesthesiology, University of California, San Francisco 94115.
Anesthesiology. 1994 Nov;81(5):1102-9. doi: 10.1097/00000542-199411000-00003.
Transesophageal echocardiography is increasingly used intraoperatively as a monitor of ventricular function and volume. Although obliteration of the left ventricular (LV) cavity at end-systole is interpreted as indicative of intraoperative hypovolemia, this relation has not been demonstrated directly.
We continuously monitored the LV short axis by using transesophageal echocardiography and determined the relation between acute changes in LV area and hemodynamic variables in 139 patients undergoing elective coronary artery bypass graft surgery. The end-diastolic areas (EDA) and end-systolic areas were calculated during the control state (after anesthetic induction) and during LV end-systolic cavity obliteration.
Thirty-nine of 139 patients had episodes of LV cavity obliteration. Mean LV end-systolic area decreased significantly from the control to obliterated state (7.29 +/- 2.56 to 4.00 +/- 1.46 cm2, P = 0.0001). The corresponding mean LV EDA also significantly decreased from the control to obliterated state (18.18 +/- 4.36 to 12.92 +/- 3.74 cm2, P = 0.0001). Mean ejection fraction area increased from 0.609 +/- 0.095 (control) to 0.692 +/- 0.083 (obliteration) (P < 0.0001). Of these 39 episodes, 31 (80%) were associated with a greater than 10% decrease in EDA relative to the initial value after induction of anesthesia and tracheal intubation; 4 (10%) with increases in ejection fraction area only; and an additional 4 (10%) with no substantial change in either the EDA or ejection fraction area. Overall, LV cavity obliteration was not associated with hemodynamic changes.
Our study demonstrates that LV cavity obliteration is rarely preceded by any acute alteration in hemodynamic parameters. Although end-systolic cavity obliteration detected by intraoperative transesophageal echocardiography is frequently associated with decreases in EDA, not every instance of end-systolic cavity obliteration is indicative of decreased left ventricular filling.
术中经食管超声心动图越来越多地用于监测心室功能和容积。虽然收缩末期左心室（LV）腔消失被解释为术中血容量不足的表现，但这种关系尚未得到直接证实。
我们使用经食管超声心动图持续监测左心室短轴，并确定了139例行择期冠状动脉旁路移植术患者左心室面积急性变化与血流动力学变量之间的关系。在对照状态（麻醉诱导后）和左心室收缩末期腔消失期间计算舒张末期面积（EDA）和收缩末期面积。
139例患者中有39例出现左心室腔消失。左心室平均收缩末期面积从对照状态到消失状态显著减小（7.29±2.56至4.00±1.46 cm²，P = 0.0001）。相应的左心室平均EDA也从对照状态到消失状态显著减小（18.18±4.36至12.92±3.74 cm²，P = 0.0001）。平均射血分数面积从0.609±0.095（对照）增加到0.692±0.083（消失）（P < 0.0001）。在这39次发作中，31次（80%）与麻醉诱导和气管插管后EDA相对于初始值下降超过10%有关；4次（10%）仅与射血分数面积增加有关；另外4次（10%）EDA或射血分数面积均无实质性变化。总体而言，左心室腔消失与血流动力学变化无关。
我们的研究表明，左心室腔消失很少先于血流动力学参数的任何急性改变。虽然术中经食管超声心动图检测到的收缩末期腔消失通常与EDA降低有关，但并非每个收缩末期腔消失的实例都表明左心室充盈减少。
