Gallagher K P, Osakada G, Matsuzaki M, Miller M, Kemper W S, Ross J
Am J Physiol. 1985 Aug;249(2 Pt 2):H241-8. doi: 10.1152/ajpheart.1985.249.2.H241.
Transmural differences in systolic wall thickening were analyzed in 13 conscious dogs by implanting sonomicrometers to continuously measure total wall thickness (WT) and outer WT approximately half the distance through the myocardium at a closely adjacent location. Inner WT was derived by subtraction of outer WT from total WT. Outer wall measurements spanned, on average, the outer 44 +/- 10% (+/- SD) of the wall; derived inner wall measurements spanned the remaining 56 +/- 10%. At rest the fractional contribution (FC) of the outer wall to total systolic wall thickening was 29 +/- 9%, which was significantly less than the FC of the inner wall, 71 +/- 9%. These data are in good agreement with simplified modeling of a cross section of the left ventricle as two concentric rings that predicts that the FC of inner and outer halves of the wall should be approximately 67 and 33%, respectively. During treadmill exercise, the extent of both inner and outer thickening increased significantly (30 and 29%, respectively) but the relative FC of the inner and outer wall remained the same. The data indicate that systolic wall thickening is nonuniform and that this nonuniformity remains constant during the increased inotropic and chronotropic stimulation associated with exercise.
通过植入超声微测仪，对13只清醒犬的跨壁收缩期壁增厚差异进行了分析，以连续测量总壁厚度（WT）和在紧邻位置穿过心肌约一半距离处的外壁厚度。内壁厚度通过从总壁厚度中减去外壁厚度得出。外壁测量平均跨越壁的外44±10%（±标准差）；由此得出的内壁测量跨越其余的56±10%。静息时，外壁对总收缩期壁增厚的分数贡献（FC）为29±9%，显著低于内壁的FC，即71±9%。这些数据与将左心室横截面简化建模为两个同心环的结果高度一致，该模型预测壁的内半部分和外半部分的FC应分别约为67%和33%。在跑步机运动期间，内壁和外壁增厚的程度均显著增加（分别为30%和29%），但内壁和外壁的相对FC保持不变。数据表明，收缩期壁增厚是不均匀的，并且在与运动相关的变力性和变时性刺激增加期间，这种不均匀性保持不变。
