Left ventricular geometry in normal and post-anterior myocardial infarction patients: sphericity index and 'new' conicity index comparisons
Left ventricular geometry in normal and post-anterior myocardial infarction patients: sphericity index and 'new' conicity index comparisons
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DOI：
10.1016/j.ejcts.2006.03.002
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发表时间：
2006-04-01
影响因子：
3.4
通讯作者：
Menicanti, Lorenzo
中科院分区：
文献类型：
--
作者：
Di Donato, Marisa;Dabic, Petar;Menicanti, Lorenzo
背景：前壁心肌梗死导致一系列结构改变，改变左心室的大小和形状。已努力通过整体左心室(W)腔分析(球形指数，SI)来评估形状，但这一分析没有发现像心尖水平那样的局部形状异常，这些异常发生在整体心室扩张之前。目的：对52例正常人和92例既往前壁心肌梗死患者的局部心尖改变进行新的分析。方法：所有患者均行经胸超声心动图检查，获得多个切面(纵轴切面、4CH切面、2CH切面和短轴切面)。从4CH角度测量齿轴和短轴，并计算其比值(球度指数)。在同一切面下，测量根尖轴长，计算根尖与短轴长度的比值(心尖锥度指数，ACI)。结果：患者除球度指数无明显变化外，其余各项测量参数均明显低于正常。前壁心肌梗死后，脑室长度和宽度增加，但两个测量值之间的比率没有改变。相反，心尖锥度指数在前壁心肌梗死后有显著不同，因此表明前壁梗死产生的锥形较少。当二尖瓣关闭不全与二尖瓣功能相关时，SI与ACI不同，SI与二尖瓣返流程度及乳头肌距离相关，ACI与二尖瓣返流影响因素呈负相关。这些观察反映了缺血性心肌病心尖部扩张与整体扩张的不同，因此当心尖部相对于短轴明显扩张(高锥度指数)时，二尖瓣功能更好(塔状帐篷面积和较低的瓣膜高度)。相反，当球形指数较高时，二尖瓣功能受损(乳头肌之间的距离较大，二尖瓣返流程度较高)。结论：球度指数能较好地检测局部根尖形态异常。为了解决这一局部变化，我们引入了一种简单的新测量方法，称为心尖锥度指数，该指数在心肌梗死患者中是异常的，可以用于评估随后的外科手术入路的心室重塑引起的变化。(C)2006爱思唯尔B.V.保留所有权利。
Background: Anterior myocardial infarction leads a sequence of structural changes that alter the size and the shape of the left ventricle. Efforts to assess shape have been made by global left ventricular (W) chamber analysis (sphericity index, SI) but this analysis does not detect regional shape abnormalities like those at the apical level, which precede global ventricular dilatation. Objective: The present study will introduce a new analysis of regional apical changes in 52 normal subjects and in 92 patients with previous anterior myocardial infarction. Methods: All patients had transthoracic echocardiogram and multiple views were obtained (tong axis, 4CH, 2CH and short axis view). From the 4CH view the tong and the short axes were measured and their ratio was calculated (sphericity index). In the same view, the apical axis length was also measured and the ratio between apical and short axis length was calculated (apical conicity index, ACI). Results: Patients had all the measured parameters significantly worse than normal, except the sphericity index which remained unchanged. Ventricular length and width increased following anterior MI but the ratio between the two measurements did not change. Conversely, apical conicity index is significantly different following anterior MI, thereby indicating anterior infarction produces a less conical shape. SI and ACI differed when correlations were made in the relationship of mitral valve function; SI correlates with the degree of mitral regurgitation (MR) and with the distance of papillary muscles, conversely ACI shows an inverse correlation with the determinants of mitral regurgitation. These observations reflect differences between apical versus global dilatation in ischemic cardiomyopathy, so that mitral function is better (tower tenting area and lower coaptation height) when the apex is markedly dilated in respect to the short axis (high conicity index). In contrast, mitral function is impaired (bigger distance between papillary muscles and higher degree of mitral regurgitation), when sphericity index is high. Conclusions: Sphericity index faits to detect regional apical shape abnormalities. To address this focal change, we introduce a simple new measure termed apical conicity index, which is abnormal in patients with myocardial infarction, and can be useful to evaluate changes induced by the subsequent surgical approach of ventricular re-shaping. (c) 2006 Elsevier B.V. All rights reserved.