心室容积减少手术对扩张且收缩功能不良的左心室的影响：一项简单的有限元分析。

The effect of ventricular volume reduction surgery in the dilated, poorly contractile left ventricle: a simple finite element analysis.

作者信息

Ratcliffe M B, Hong J, Salahieh A, Ruch S, Wallace A W

机构信息

Department of Surgery, School of Medicine of the University of California, San Francisco, San Francisco Veterans Affairs Medical Center, 94121, USA.

出版信息

J Thorac Cardiovasc Surg. 1998 Oct;116(4):566-77. doi: 10.1016/S0022-5223(98)70162-X.

DOI:10.1016/S0022-5223(98)70162-X

PMID:9766584

Abstract

OBJECTIVES

Ventricular volume reduction surgery has been proposed by Batista to improve cardiac function in patients with dilated cardiomyopathy. However, limited clinical data exist to determine the efficacy of this operation. A finite element simulation is therefore used to determine the effect of volume reduction surgery on left ventricular end-systolic elastance, diastolic compliance, stroke work/end-diastolic volume (preload recruitable stroke work), and stroke work/end-diastolic pressure (Starling) relationships.

METHODS

End-diastole and end-systole were represented by elastic finite element models with different unloaded shapes and nonlinear material properties. End-systolic elastance, diastolic compliance, preload recruitable stroke work, and Starling relationships, as well as energy expenditure per gram of unresected myocardium, were calculated. Two different types of volume reduction surgery (apical and lateral) were simulated at 10% and 20% left ventricular mass reduction.

RESULTS

Ventricular volume reduction surgery causes diastolic compliance to shift further to the left on the pressure-volume diagram than end-systolic elastance. Volume reduction surgery increases the slope of the preload recruitable stroke work relationship (dilated cardiomyopathy 0.006 J/mL; 20% lateral volume reduction surgery 0.009 J/mL) but decreases the slope of the Starling relationship (dilated cardiomyopathy 0.028 J/mm Hg; 20% lateral volume reduction 0.023 J/mm Hg). For a given amount of resection, lateral volume reduction has a greater effect than apical volume reduction. Ten-percent and 20% lateral volume reduction reduces energy expenditure by 7% and 17%, respectively.

CONCLUSION

Ventricular volume reduction surgery shifts end-systolic elastance and diastolic compliance to the left on the pressure-volume diagram. The net effect on ventricular function is mixed. Volume reduction surgery increases the slope of preload recruitable stroke work, but increased diastolic compliance causes a small decrease in the Starling relationship (3 mm Hg difference between dilated cardiomyopathy and volume reduction surgery at stroke work = 0.5 J).

摘要

目的

巴蒂斯塔提出心室减容手术以改善扩张型心肌病患者的心脏功能。然而，确定该手术疗效的临床数据有限。因此，采用有限元模拟来确定减容手术对左心室收缩末期弹性、舒张顺应性、每搏功/舒张末期容积（可募集前负荷每搏功）以及每搏功/舒张末期压力（斯塔林）关系的影响。

方法

舒张末期和收缩末期由具有不同无负荷形状和非线性材料特性的弹性有限元模型表示。计算收缩末期弹性、舒张顺应性、可募集前负荷每搏功、斯塔林关系以及每克未切除心肌的能量消耗。在左心室质量减少10%和20%的情况下模拟两种不同类型的减容手术（心尖部和侧壁）。

结果

心室减容手术使舒张顺应性在压力-容积图上比收缩末期弹性更向左偏移。减容手术增加了可募集前负荷每搏功关系的斜率（扩张型心肌病为0.006 J/mL；侧壁减容手术20%为0.009 J/mL），但降低了斯塔林关系的斜率（扩张型心肌病为0.028 J/mm Hg；侧壁减容20%为0.023 J/mm Hg）。对于给定的切除量，侧壁减容比心尖部减容的效果更大。侧壁减容10%和20%分别使能量消耗降低7%和17%。