Pearlman E S, Weber K T, Janicki J S, Pietra G G, Fishman A P
Lab Invest. 1982 Feb;46(2):158-64.
To elucidate the structural correlates of cardiac failure in myocardial tissue, muscle fiber alignment and connective tissue volume fraction were measured at multiple sites in the left ventricular free wall and in the interventricular septum of 14 human hearts. Group 1 (five hearts; 280 +/- 20 gm.) had no evidence of cardiac disease, group 2 (five hearts; 380 +/- 30 gm.) had a history of systemic hypertension without clinical heart failure, and group 3 (four hearts;; 590 +/- 40 gm.) had both left ventricular overload and congestive failure. Fiber orientations were determined by measuring fiber angle relative to the circumferential direction (helix angle). The fraction of the myocardial volume occupied by connective tissue was determined by point counting. Our results indicate a smooth transition of helix angle from epi- to endocardial surface in the normal left ventricular free wall with nearly 55 per cent of the wall occupied by circumferentially oriented fibers near the cardiac equator (latitude of largest ventricular diameter); morphologically, the interventricular septum was nearly identical with the free wall. Fiber alignment was maintained in all three groups as was the fraction of wall occupied by circumferential fibers. Connective tissue volume fraction was, however, significantly increased (p less than 0.02) in hypertrophied hearts (groups 2 and 3) as compared with normal hearts, and at two of six sites in clinically failed hearts as compared with hypertrophied but functionally compensated hearts. Thus, muscle fiber orientation is not altered in the hypertrophied pressure-overloaded left ventricle, whereas connective tissue content is increased with the increase being greatest in the failing heart.
为阐明心肌组织中心力衰竭的结构关联，在14例人类心脏的左心室游离壁和室间隔的多个部位测量了肌纤维排列和结缔组织体积分数。第1组（5例心脏；280±20克）无心脏病证据，第2组（5例心脏；380±30克）有系统性高血压病史但无临床心力衰竭，第3组（4例心脏；590±40克）既有左心室负荷过重又有充血性心力衰竭。通过测量纤维相对于圆周方向的角度（螺旋角）来确定纤维方向。通过点计数确定结缔组织占心肌体积的比例。我们的结果表明，在正常左心室游离壁中，螺旋角从心外膜表面到心内膜表面呈平滑过渡，在心脏赤道附近（心室最大直径的纬度），近55%的壁由圆周方向排列的纤维占据；形态学上，室间隔与游离壁几乎相同。三组中纤维排列均得以维持，圆周纤维所占壁的比例也如此。然而，与正常心脏相比，肥厚心脏（第2组和第3组）中结缔组织体积分数显著增加（p<0.02），与肥厚但功能代偿的心脏相比，临床心力衰竭心脏的六个部位中有两个部位的结缔组织体积分数增加。因此，在压力负荷过重的肥厚左心室中，肌纤维方向未改变，而结缔组织含量增加，且在衰竭心脏中增加最为明显。
