心肌梗死后左心室室壁瘤：室壁瘤切除术后的局部应力、功能及重塑

Postinfarction left-ventricular aneurysm: regional stress, function, and remodeling after aneurysmectomy.

作者信息

Taniguchi K, Sakurai M, Takahashi T, Imagawa H, Mitsuno M, Nakano S, Kawashima Y, Matsuda H

机构信息

First Department of Surgery, Osaka University Medical School, Japan.

出版信息

Thorac Cardiovasc Surg. 1998 Oct;46(5):253-9. doi: 10.1055/s-2007-1010234.

DOI:10.1055/s-2007-1010234

PMID:9885114

Abstract

BACKGROUND

Left-ventricular (LV) aneurysm formation after myocardial infarction (MI) leads to LV remodeling with global and regional cardiac dysfunction. LV aneurysmectomy (LVA) can often improve LV function, but changes of regional wall stress and systolic function in the noninfarcted segment before and after the operation remain poorly understood. The purpose of this study was to assess the effects of LVA on regional stress and systolic function in the noninfarcted region and to examine this procedure's impact on the LV remodeling in patients with LV aneurysm after myocardial infarction (MI).

METHODS

Using quantitative left ventriculography and pressure measurements, 11 patients with an anterior LV aneurysm were studied before and 8 months after standard linear repair (LVA group), and 10 patients with an anterior transmural infarction who received coronary artery bypass grafting were also studied (CABG group) in an attempt to separate the effects of aneurysmectomy from the effects of bypass surgery. Regional end-systolic (ESS) and end-diastolic (EDS) stresses of the contractile segment (CS) were computed by Janz's method.

RESULTS

The total ejection fraction (EF) increased (p < 0.01) in the LVA group, whereas it did not change in the CABG group at 8 months after surgery. Both the end-diastolic and end-systolic volume indices of CS decreased (p < 0.01 and p < 0.01, respectively) in the LVA group, whereas both remained unchanged in the CABG group. The mean velocity of circumferential fiber shortening (mean Vcf) of CS increased substantially (p < 0.01) in the LVA group and, less significantly (p < 0.05), in the CABG group. Regional ESS and EDS decreased (p < 0.01 and p < 0.05, respectively) in the LVA group, whereas both remained unchanged in the CABG group. The increase in mean Vcf correlated strongly with the magnitude of decrease in ESS (r = -0.63, p < 0.01) in the LVA group but not in the CABG group.

CONCLUSIONS

LVA can reduce regional afterload and improve ejection performance of the noninfarcted myocardium in many patients with a large anterior LV aneurysm and, moreover, may favorably affect the LV remodeling process after MI.

摘要

背景

心肌梗死（MI）后左心室（LV）动脉瘤形成会导致LV重塑，并伴有整体和局部心脏功能障碍。左心室动脉瘤切除术（LVA）通常可改善LV功能，但手术前后非梗死节段的局部壁应力和收缩功能变化仍了解甚少。本研究的目的是评估LVA对非梗死区域局部应力和收缩功能的影响，并研究该手术对心肌梗死（MI）后左心室动脉瘤患者LV重塑的影响。

方法

使用定量左心室造影和压力测量，对11例患有前壁LV动脉瘤的患者在标准线性修复术前及术后8个月进行研究（LVA组），并对10例接受冠状动脉旁路移植术的前壁透壁性梗死患者进行研究（CABG组），以试图区分动脉瘤切除术的效果与旁路手术的效果。通过扬茨方法计算收缩节段（CS）的局部收缩末期（ESS）和舒张末期（EDS）应力。

结果

LVA组的总射血分数（EF）增加（p < 0.01），而CABG组在术后8个月时未发生变化。LVA组CS的舒张末期和收缩末期容积指数均降低（分别为p < 0.01和p < 0.01），而CABG组两者均保持不变。LVA组CS的圆周纤维平均缩短速度（平均Vcf）大幅增加（p < 0.01），CABG组增加幅度较小（p < 0.05）。LVA组的局部ESS和EDS降低（分别为p < 0.01和p < 0.05），而CABG组两者均保持不变。LVA组平均Vcf的增加与ESS降低幅度密切相关（r = -0.63，p < 0.01），而CABG组则无此相关性。