Cabrera Schulmeyer M C, Farías J, De la Maza J
Departamento de Anestesiología, Universidad de Valparaíso, Hospital Clínico FACH, Santiago de Chile.
Rev Esp Anestesiol Reanim. 2011 Nov;58(9):543-7. doi: 10.1016/s0034-9356(11)70138-4.
Transesophageal echocardiography is appropriate for intraoperative monitoring of hemodynamics. The parameter often estimated is ejection fraction (EF) by means of Simpson's rule. With the advent of tissue Doppler imaging and measurement of the systolic (S) wave, corresponding to the rate of myocardial perfusion during the systole, it is possible to estimate the EF more easily and rapidly during surgery.
To compare EF estimates obtained by Simpson's rule to those based on intraoperative tissue Doppler measurements of S-wave velocity (S').
Patients with chronic cardiovascular disease undergoing scheduled cardiac and noncardiac surgery were studied. Patients in nonsinus rhythm and with mitral valve disease were excluded. To apply Simpson's rule for calculating the EF, we measured end-diastolic volume in 4- and 2-chamber views. The group was divided into patients with normal (> or = 50%) and diminished (< or = 49%) ejection fraction. Tissue Doppler imaging of the mitral annulus was then used to measure S'. Ejection fraction was calculated according to the formula EF = 5.5 x S' + 8.
Ninety-two patients were studied; in 51 (55%) the EF was normal and in 41 (45%) it was reduced. In patients whose EF was < or = 49% according to Simpson's rule, the correlation between that measurement and EF based on tissue Doppler estimate of S' was good. The correlation was lower, however, in the group with normal EF (r=0.61; P>0.5).
EF is easy to estimate with tissue Doppler imaging and the procedure is reproducible. This approach is probably more useful in patients with left ventricular dysfunction.
经食管超声心动图适用于术中血流动力学监测。常用Simpson法则估算射血分数（EF）。随着组织多普勒成像技术的出现以及对与收缩期心肌灌注速率相对应的收缩期（S）波的测量，术中更轻松、快速地估算EF成为可能。
比较通过Simpson法则获得的EF估算值与基于术中组织多普勒测量S波速度（S'）得出的估算值。
对计划进行心脏及非心脏手术的慢性心血管疾病患者展开研究。排除非窦性心律及患有二尖瓣疾病的患者。为应用Simpson法则计算EF，我们在四腔心和两腔心视图中测量舒张末期容积。将该组患者分为射血分数正常（≥50%）和降低（≤49%）的患者。然后使用二尖瓣环的组织多普勒成像测量S'。根据公式EF = 5.5×S' + 8计算射血分数。
共研究了92例患者；其中51例（55%）EF正常，41例（45%）EF降低。根据Simpson法则，EF≤49%的患者中，该测量值与基于组织多普勒S'估算的EF之间相关性良好。然而，在EF正常的组中相关性较低（r = 0.61；P>0.5）。
使用组织多普勒成像估算EF简便易行且可重复性强。这种方法可能对左心室功能不全患者更有用。
