慢性阻塞性肺病纵隔应变对“小心脏”形成的力学分析

MECHANICAL ANALYSIS OF"SMALL HEART" CAUSED BYCHRONIC OBSTRUCTIVE PULMONARY DISEASE MEDIATINALSTRAIN

本文通过对COPD病人纵隔及心包膜壁层(下简称心包)的应力—应变分析,认为COPD病人纵隔应变程度已不容忽视,将导致其应力增加并在心包处集中而影响心包。按心包的平衡方程,心包应力增加导致其曲率减小,中点挠度减小,心包移向纵隔中位。同时,心脏舒张期充盈阻力增加、充盈量减少,因而心搏量减少而次数增加。提出COPD病人纵隔应变也是其“小心脏”发生的原因之一。

<ABSTRACT> This paper analyzes mediastinal and pericardial stress--strain in COPD patients and the author suggests that the mediastinum deformation of COPD patients should not be neglected. It leads to the stress growth in it; the stress is accumulated around and effects on the pericardium. Ac- cording to the pericardium's balance equation proposed by the author, the stress increase can result in the decrease of pericardium curvature and medi- an deflection and pericardium displacement towards mediastinum center. Be- cause of the supercharging resistance increase and filling-amount decrease during diastole, the stroke volume becomes gradually lessened with sim- ultaneous increase of heart beat, indicating that mediastinum deformati- on of COPD patients is also one of the cause of 'small heart'deformity.