Mohan J C, Agarwal R, Arora R
Department of Cardiology, G.B. Pant Hospital, New Delhi, India.
Indian Heart J. 1994 Mar-Apr;46(2):107-11.
The purpose of this study was to investigate possible differences between juvenile and adult variety of mitral stenosis (MS) with regard to left ventricular preload, afterload, contractile function and geometry by two-dimensional echocardiography. Thirty six consecutive children and adolescents with MS (Group 1, mean age +/- 1 standard deviation 16 +/- 3 yrs) were compared with an equal number of adults with MS of comparable mitral valve area (Group II, mean age 30 +/- 8 yrs). Patients with juvenile versus adult MS had similar left ventricular ejection fraction (0.57 +/- 0.09 vs 0.57 +/- 0.11, p = not significant (NS)), end-systolic wall stress (64.8 +/- 21 vs 64.3 +/- 25 Kdynes/cm2, p = NS), wall stress to end-systolic volume ratio (2.6 +/- 1.2 vs 2.71 +/- 0.9, p = NS) and mass (77 +/- 19 vs 83 +/- 26 gm/m2 p = NS) but the former had greater end diastolic volume (68 +/- 16 vs 57 +/- 18 ml/m2, p = 0.008) and sphericity index (0.62 +/- 0.19 vs 0.50 +/- 0.19, p = 0.01) and lower mass to volume ratio (1.01 +/- 0.32 vs 1.36 +/- 0.42, p (0.01). Compared to normal controls, adult patients with MS had similar end-diastolic volume (58 +/- 13 vs 57 +/- 18 ml/m2), mass (84 +/- 20 vs 83 +/- 26 gm/m2), mass to volume ratio (1.45 +/- 0.4 vs 1.36 +/- 0.42) but greater wall stress (45.6 +/- 11.7 vs 64.3 +/- 25 Kdynes/cm2, p < 0.001) and lower ejection fraction (0.66 +/- 0.07 vs 0.57 +/- 0.11, p < 0.001). Thus patients with juvenile MS have significantly altered left ventricular geometry and increased preload in response to comparably elevated afterload due to compensatory adaptive process.
本研究旨在通过二维超声心动图，调查青少年和成人二尖瓣狭窄（MS）在左心室前负荷、后负荷、收缩功能及几何形态方面可能存在的差异。选取36例连续性儿童及青少年MS患者（第1组，平均年龄±1个标准差16±3岁），并与同等数量、二尖瓣瓣口面积相当的成人MS患者（第2组，平均年龄30±8岁）进行比较。青少年与成人MS患者的左心室射血分数相似（0.57±0.09对0.57±0.11，p=无显著差异（NS）），收缩末期壁应力相似（64.8±21对64.3±25Kdynes/cm2，p=NS），壁应力与收缩末期容积比相似（2.6±1.2对2.71±0.9，p=NS），质量相似（77±19对83±26gm/m2，p=NS），但前者舒张末期容积更大（68±16对57±18ml/m2，p=0.008），球形指数更高（0.62±0.19对0.50±0.19，p=0.01），质量与容积比更低（1.01±0.32对1.36±0.42，p=0.01）。与正常对照组相比，成人MS患者舒张末期容积相似（58±13对57±18ml/m2），质量相似（84±20对83±26gm/m2），质量与容积比相似（1.45±0.4对1.36±0.42），但壁应力更大（45.6±11.7对64.3±25Kdynes/cm2，p<0.001），射血分数更低（0.66±0.07对0.57±0.11，p<0.001）。因此，青少年MS患者由于代偿性适应过程，在面对同等升高的后负荷时，左心室几何形态显著改变，前负荷增加。
