Koth Andrew M, Axelrod David M, Reddy Sushma, Roth Stephen J, Tacy Theresa A, Punn Rajesh
Division of Pediatric Cardiology, Department of Pediatrics, Lucile Packard Children's Hospital at Stanford, Stanford University School of Medicine, 750 Welch Road, Suite # 325, Palo Alto, CA, 94304, USA.
Pediatr Cardiol. 2017 Mar;38(3):539-546. doi: 10.1007/s00246-016-1546-9. Epub 2016 Dec 22.
The effect of veno-arterial extracorporeal membrane oxygenation (VA ECMO) on wall stress in patients with cardiomyopathy, myocarditis, or other cardiac conditions is unknown. We set out to determine the circumferential and meridional wall stress (WS) in patients with systemic left ventricles before and during VA ECMO. We established a cohort of patients with impaired myocardial function who underwent VA ECMO therapy from January 2000 to November 2013. Demographic and clinical data were collected and inotropic score calculated. Measurements were taken on echocardiograms prior to the initiation of VA ECMO and while on full-flow VA ECMO, in order to derive wall stress (circumferential and meridional), VCFc, ejection fraction, and fractional shortening. A post hoc sub-analysis was conducted, separating those with pulmonary hypertension (PH) and those with impaired systemic output. Thirty-three patients met inclusion criteria. The patients' median age was 0.06 years (range 0-18.7). Eleven (33%) patients constituted the organ failure group (Gr2), while the remaining 22 (66%) patients survived to discharge (Gr1). WS and all other echocardiographic measures were not different when comparing patients before and during VA ECMO. Ejection and shortening fraction, WS, and VCFc were not statistically different comparing the survival and organ failure groups. The patients' position on the VCFc-WS curve did not change after the initiation of VA ECMO. Those with PH had decreased WS as well as increased EF after ECMO initiation, while those with impaired systemic output showed no difference in those parameters with initiation of ECMO. The external workload on the myocardium as indicated by WS is unchanged by the institution of VA ECMO support. Furthermore, echocardiographic measures of cardiac function do not reflect the changes in ventricular performance inherent to VA ECMO support. These findings are informative for the interpretation of echocardiograms in the setting of VA ECMO. ECMO may improve ventricular mechanics in those with PH as the primary diagnosis.
静脉-动脉体外膜肺氧合（VA ECMO）对心肌病、心肌炎或其他心脏疾病患者壁应力的影响尚不清楚。我们着手确定在VA ECMO治疗前及治疗期间，系统性左心室患者的圆周壁应力和子午线壁应力（WS）。我们建立了一组心肌功能受损且在2000年1月至2013年11月期间接受VA ECMO治疗的患者队列。收集了人口统计学和临床数据，并计算了肌力评分。在开始VA ECMO之前以及在全流量VA ECMO期间进行超声心动图测量，以得出壁应力（圆周和子午线）、心肌纤维缩短速度（VCFc）、射血分数和缩短分数。进行了事后亚组分析，将患有肺动脉高压（PH）的患者和全身输出受损的患者分开。33名患者符合纳入标准。患者的中位年龄为0.06岁（范围0 - 18.7岁）。11名（33%）患者构成器官衰竭组（Gr2），其余22名（66%）患者存活至出院（Gr1）。比较VA ECMO治疗前和治疗期间的患者时，WS和所有其他超声心动图测量结果无差异。比较存活组和器官衰竭组时，射血分数和缩短分数、WS和VCFc无统计学差异。开始VA ECMO后，患者在VCFc - WS曲线上的位置没有变化。患有PH的患者在开始ECMO后WS降低且EF增加，而全身输出受损的患者在开始ECMO后这些参数没有差异。VA ECMO支持并未改变WS所指示的心肌外部工作负荷。此外,心脏功能的超声心动图测量结果并未反映出VA ECMO支持所固有的心室功能变化。这些发现对于在VA ECMO背景下解释超声心动图具有参考价值。ECMO可能改善以PH为主要诊断的患者的心室力学。
