REGIONAL EPICARDIAL AND ENDOCARDIAL 2-DIMENSIONAL FINITE DEFORMATIONS IN CANINE LEFT-VENTRICLE
REGIONAL EPICARDIAL AND ENDOCARDIAL 2-DIMENSIONAL FINITE DEFORMATIONS IN CANINE LEFT-VENTRICLE
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DOI：
10.1152/ajpheart.1991.261.5.h1402
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发表时间：
1991-11-01
影响因子：
--
通讯作者：
MILLER, DC
中科院分区：
文献类型：
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作者：
FANN, JI;SARRIS, GE;MILLER, DC
我们评估了心外膜下和心内膜下的二维有限变形在左心室（LV）前，侧，后区在闭胸，清醒的狗的心脏。8只犬在LV心肌中放置了22个不透射线标记。在心室中部水平的前、侧和后心外膜下和内膜下植入三组标记物;将参考标记物放置在心尖和基底部位。8小时后，进行了双平面视频透视。在呼气末连续三次搏动期间，分析每个心外膜下和心内膜下区域的有限变形。环向缩短发生在所有层和区域;同样，纵向缩短发生在所有层中，除了后内膜。主应变值分别为前内膜下和心外膜下-0.19 +/- 0.08（SD）和-0.10 +/- 0.03，外内膜下和心外膜下-0.20 +/- 0.07和-0.10 +/- 0.02，后内膜下和心外膜下分别为-0.13 ± 0.02和-0.10 ± 0.03（P < 0.05）。在所有区域中，第二主应变趋于接近零或正值（从-0.01 +/-0.05至0.04 +/-0.05）。收缩末期主应变方向：前心外膜下和心内膜下分别为-29 +/- 32 °和-34 +/- 29 °，外侧心外膜下和心内膜下分别为-47 +/- 10 °和-30 +/- 37 °，后心外膜下和心内膜下分别为-4 +/- 29 °和+7 +/- 23 °。主应变的前向和侧向在心外膜下和心内膜下层中是相似的，并且沿着心外膜纤维轴定向，但是后向倾向于周向定向。这种区域不均匀性可能是纤维几何形状不均匀、后壁心外膜和心内膜影响均衡或两者兼而有之的结果。
We evaluated subepicardial and subendocardial two-dimensional finite deformations in the left ventricular (LV) anterior, lateral, and posterior regions in the closed-chest, conscious dog heart. Eight dogs underwent placement of 22 radiopaque markers in the LV myocardium. Sets of three markers were implanted in the anterior, lateral, and posterior subepicardium and subendocardium at the mid-ventricular level; reference markers were placed at apical and basal sites. Eight hours later, biplane videofluoroscopy was performed. Finite deformations for each subepicardial and subendocardial region were analyzed during three consecutive beats at end expiration. Circumferential shortening occurred in all layers and regions; similarly, longitudinal shortening occurred in all layers except that of the posterior endocardium. Values of principal strain were -0.19 +/- 0.08 (SD) and -0.10 +/- 0.03 for the anterior subendocardium and subepicardium, -0.20 +/- 0.07 and -0.10 +/- 0.02 for the lateral subendocardium and subepicardium, and -0.13 +/- 0.02 and -0.10 +/- 0.03 for the posterior subendocardium and subepicardium respectively (P < 0.05 subendocardium vs. subepicardium). Second principal strain tended to be near zero or positive (from -0.01 +/- 0.05 to 0.04 +/- 0.05) in all regions. The end-systolic direction of principal strain was -29 +/- 32-degrees and -34 +/- 29-degrees in the anterior subepicardium and subendocardium, -47 +/- 10-degrees and -30 +/- 37-degrees in the lateral subepicardium and subendocardium, and -4 +/- 29-degrees and +7 +/- 23-degrees in the posterior subepicardium and subendocardium. Anterior and lateral directions of principal strain were similar in the subepicardial and subendocardial layers and oriented along the epicardial fiber axis, but the posterior direction tended to be circumferentially oriented. This regional heterogeneity may be the result of heterogeneous fiber geometry, equalization of epicardial and endocardial influences in the posterior wall, or both.