National Heart Centre Singapore, Mistri Wing 17 Third Hospital Avenue, Singapore, Singapore.
Med Eng Phys. 2011 Nov;33(9):1120-6. doi: 10.1016/j.medengphy.2011.05.003.
This paper contains (i) derivation of the aorto-ventricular matching (AVM) index in terms of the ratio of aortic elastance and LV end-systolic elastance, E(aorta)/E(es); (ii) procedure for determination of this index, by means of non-invasive measurements of auscultatory pressures, time-variation of blood volume ejected into the aorta, stroke volume and ejection fraction; (iii) results of improved AVM index evaluation in ischemic dilated cardiomyopathy (IDCM) patients following surgical ventricular restoration (SVR), as a result of reduced end-diastolic and end-systolic LV volumes and increased LV E(es).
Among the ten recruited IDCM patients, four of them underwent surgical ventricular restoration (SVR) and coronary artery bypass graft (CABG), while six of them underwent CABG alone. All patients were studied by echocardiography pre- and 4 months post-operatively; LV volumes were determined by echo Doppler. LV end-systolic elastance E(es) was determined from a derived expression, by employing blood pressure, stroke volume, ejection fraction, pre-ejection and systolic periods, and estimated normalized ventricular elastance at end-diastole, based on single-beat measurements. Aortic elastance E(aorta) was determined by means of our modified single-beat method for determining aortic pressure profile.
In the CABG plus SVR group, the AVM index E(aorta)/E(es) was reduced by 35% from 0.93±0.32 to 0.60±0.33, consistent with improved aorto-ventricular matching. However, in the CABG alone group, the AVM index E(aorta)/E(es) decreased only 11% from 1.02±0.24 to 0.91±0.29.
There is shown to be increased value of LV E(es) and a more favorable decreased value of AVM index in those IDCM patients who underwent SVR.
本文包含（i）根据主动脉弹性和左心室收缩末期弹性的比值，即主动脉弹性与左心室收缩末期弹性之比（E(aorta)/E(es)），推导出的房室匹配指数；（ii）通过非侵入性测量听诊压力、血液流入主动脉的时间变化、心搏量和射血分数，确定该指数的程序；（iii）通过外科心室修复（SVR）后缺血性扩张型心肌病（IDCM）患者的房室匹配指数评估得到改善的结果，这是由于左心室舒张末期和收缩末期容积减少以及左心室收缩末期弹性增加。
在 10 名招募的 IDCM 患者中，4 名患者接受了外科心室修复（SVR）和冠状动脉旁路移植术（CABG），而 6 名患者仅接受了 CABG。所有患者均在术前和术后 4 个月进行超声心动图检查；左心室容积通过超声心动图多普勒确定。左心室收缩末期弹性 E(es) 通过推导出的表达式确定，方法是利用血压、心搏量、射血分数、射血前期和收缩期，以及基于单次搏动测量的估计末舒张期标准化心室弹性。主动脉弹性 E(aorta) 通过我们改进的单次搏动方法确定主动脉压力曲线。
在 CABG 加 SVR 组中，房室匹配指数 E(aorta)/E(es) 从 0.93±0.32 降低到 0.60±0.33，降低了 35%，表明房室匹配得到改善。然而，在 CABG 单独组中，房室匹配指数 E(aorta)/E(es) 仅从 1.02±0.24 降低到 0.91±0.29，降低了 11%。
在接受 SVR 的 IDCM 患者中，左心室收缩末期弹性 E(es) 增加，房室匹配指数 E(aorta)/E(es) 降低幅度更大，具有更高的价值。
