Miyawaki H, Tsuiki K, Yamaguchi S, Ohta I, Sukekawa H, Ikeda H, Yasui S
1st Department of Internal Medicine, Yamagata University School of Medicine, Japan.
Jpn Circ J. 1991 Dec;55(12):1211-23. doi: 10.1253/jcj.55.1211.
The functional response of the left ventricle with scar to increased afterload, was examined in 15 patients with old myocardial infarction and left ventricular aneurysm (OMI). Interventional cine left ventriculography during elevating left ventricular pressure with methoxamine. Wall motion was assessed by the radial and the centerline method. Augmented afterload didn't change ejection fraction in patients with OMI, but normalized wall motion (Z) increased in the aneurysmal region and decreased in the remote region in both methods. In the remote region in patients with OMI, afterload stress shortened left ventricular pressure-radial length (P-L) loops along length axis, and reduced percent systolic radial shortening (SS). In the aneurysmal region, P-L loops showed systolic elongation of length at rest and the slope of end-diastolic point to end-systolic point became steeper with increased afterload, resulting in a decrease of aneurysmal expansion. In summary, with increasing afterload, wall motion decreased in non-infarcted regions and increased in aneurysmal regions, in left ventricles with aneurysm. This mechanism may be interpreted as afterload-induced shifts of P-L loops in each region.
在15例陈旧性心肌梗死合并左心室室壁瘤（OMI）患者中，研究了有瘢痕的左心室对后负荷增加的功能反应。使用甲氧明升高左心室压力时进行介入性电影左心室造影。采用径向法和中心线法评估室壁运动。后负荷增加时，OMI患者的射血分数未改变，但两种方法均显示，瘤壁区域的标准化室壁运动（Z）增加，而远隔区域的标准化室壁运动（Z）减少。在OMI患者的远隔区域，后负荷应激使左心室压力-径向长度（P-L）环沿长度轴缩短，并降低了收缩期径向缩短百分比（SS）。在瘤壁区域，P-L环显示静息时长度的收缩期延长，随着后负荷增加，舒张末期点至收缩末期点的斜率变得更陡，导致瘤壁扩张减小。总之，在合并室壁瘤的左心室中，随着后负荷增加，非梗死区域的室壁运动减少，瘤壁区域的室壁运动增加。这种机制可解释为后负荷引起的每个区域P-L环的移位。
