Mandegar Mohammad Hossein, Yousefnia Mohammad Ali, Roshanali Farideh, Rayatzadeh Hussein, Alaeddini Farshid
Day General Hospital, Tehran, Iran.
J Thorac Cardiovasc Surg. 2008 Oct;136(4):930-6. doi: 10.1016/j.jtcvs.2007.11.061. Epub 2008 May 12.
In patients with ischemic cardiomyopathy and substantial amounts of dysfunctional but viable myocardium, revascularization cannot always improve the left ventricular ejection fraction. We sought to investigate the interaction between the left ventricular volume and the amount of viable myocardium to predict the left ventricular ejection fraction increase after revascularization.
Eighty-five consecutive patients with a depressed left ventricular ejection fraction (mean: 27.3% +/- 5.2%) underwent coronary artery bypass grafting after a dobutamine stress echocardiography had determined that they had at least 4 viable segments. Six months after coronary artery bypass grafting, left ventricular ejection fraction and regional wall motion were reassessed.
Although the left ventricular ejection fraction was expected to recover more than 5% in all 85 patients after coronary artery bypass grafting, it did not improve in 15 patients (17.6%) despite the presence of viable segments. The likelihood of the left ventricular ejection fraction recovery decreased proportionally with an increase in the left ventricular end-systolic volume. The nonimprovers had a higher left ventricular end-systolic volume (164.2 +/- 22.4 mL vs 125.6 +/- 23.4 mL, P = .0001). In addition, the number of viable segments during the dobutamine stress echocardiography had a significant correlation with the ejection fraction increase after 6 months (P < .0001). Patients with 6 viable segments showed a good outcome irrespective of their left ventricular end-systolic volume. In patients with fewer than 6 viable segments, left ventricular end-systolic volume was a major factor in the prognosis: Patients with left ventricular end-systolic volume of 145 or more had a poor left ventricular ejection fraction increase and vice versa.
The extent of left ventricular remodeling determines the rate of functional improvement after coronary artery bypass grafting. Patients with a high left ventricular end-systolic volume and fewer than 6 viable segments have a lower likelihood of improvement.
在患有缺血性心肌病且存在大量功能失调但存活心肌的患者中，血运重建并不总能改善左心室射血分数。我们试图研究左心室容积与存活心肌量之间的相互作用，以预测血运重建后左心室射血分数的增加情况。
85例连续的左心室射血分数降低（平均：27.3%±5.2%）的患者，在多巴酚丁胺负荷超声心动图确定他们至少有4个存活节段后，接受了冠状动脉旁路移植术。冠状动脉旁路移植术后6个月，重新评估左心室射血分数和室壁节段运动。
尽管预计所有85例患者冠状动脉旁路移植术后左心室射血分数会恢复超过5%，但15例患者（17.6%）尽管存在存活节段，其左心室射血分数并未改善。左心室射血分数恢复的可能性随左心室收缩末期容积的增加成比例降低。未改善者的左心室收缩末期容积更高（164.2±22.4 mL对125.6±23.4 mL，P = ．0001）。此外，多巴酚丁胺负荷超声心动图检查时存活节段的数量与6个月后射血分数的增加有显著相关性（P < ．0001）。有6个存活节段的患者无论其左心室收缩末期容积如何，均显示出良好预后。在存活节段少于6个的患者中，左心室收缩末期容积是预后的主要因素：左心室收缩末期容积为≥145的患者左心室射血分数增加不佳，反之亦然。
左心室重构的程度决定了冠状动脉旁路移植术后功能改善的速率。左心室收缩末期容积高且存活节段少于6个的患者改善的可能性较低。
