左心室形态是心力衰竭中功能性二尖瓣反流的主要决定因素。

Left ventricular shape is the primary determinant of functional mitral regurgitation in heart failure.

作者信息

Kono T, Sabbah H N, Rosman H, Alam M, Jafri S, Goldstein S

机构信息

Henry Ford Heart and Vascular Institute, Division of Cardiovascular Medicine, Detroit, Michigan.

出版信息

J Am Coll Cardiol. 1992 Dec;20(7):1594-8. doi: 10.1016/0735-1097(92)90455-v.

DOI:10.1016/0735-1097(92)90455-v

PMID:1452934

Abstract

OBJECTIVES

The aim of this study was to examine the temporal association between the onset of functional mitral regurgitation and the development of changes in left ventricular shape, chamber enlargement, mitral anulus dilation and regional wall motion abnormalities during the course of evolving heart failure.

BACKGROUND

Despite extensive characterization, the exact etiology of functional mitral regurgitation in patients with chronic heart failure remains unknown.

METHODS

Heart failure was produced in seven dogs by multiple sequential intracoronary microembolizations. Serial changes in left ventricular chamber volume and shape were evaluated from ventriculograms. Changes in mitral anulus diameter and ventricular regional wall motion abnormalities were evaluated echocardiographically. The presence and severity of mitral regurgitation were determined with Doppler color flow mapping. Measurements were obtained at baseline and then biweekly until mitral regurgitation was first observed.

RESULTS

No dog had mitral regurgitation at baseline but all developed mild to moderate regurgitation 12 +/- 1 weeks after the first embolization. The onset of mitral regurgitation was not associated with an increase in left ventricular end-diastolic volume relative to baseline (58 +/- 3 vs. 62 +/- 3 ml), mitral anulus diameter (2.4 +/- 0.1 vs. 2.4 +/- 0.1 cm) or wall motion abnormalities of left ventricular wall segments overlying the papillary muscles. In contrast, the onset of mitral regurgitation was accompanied by significant changes in global left ventricular shape evidenced by increased end-systolic chamber sphericity index (0.22 +/- 0.02 vs. 0.30 +/- 0.01) (p < 0.01) and decreased end-systolic major axis/minor axis ratio (1.71 +/- 0.05 vs. 1.43 +/- 0.04) (p < 0.001).

CONCLUSIONS

These data indicate that transformation of left ventricular shape (increased chamber sphericity) is the most likely substrate for the development of functional mitral regurgitation.

摘要

目的

本研究旨在探讨功能性二尖瓣反流的发生与心力衰竭进展过程中左心室形状改变、腔室扩大、二尖瓣环扩张及局部室壁运动异常之间的时间关联。

背景

尽管已有广泛的特征描述，但慢性心力衰竭患者功能性二尖瓣反流的确切病因仍不清楚。

方法

通过多次序贯冠状动脉内微栓塞在7只犬身上诱发心力衰竭。从心室造影评估左心室腔容积和形状的系列变化。通过超声心动图评估二尖瓣环直径变化和心室局部室壁运动异常。用多普勒彩色血流图确定二尖瓣反流的存在和严重程度。在基线时进行测量，然后每两周测量一次，直至首次观察到二尖瓣反流。

结果

所有犬在基线时均无二尖瓣反流，但在首次栓塞后12±1周均出现轻至中度反流。二尖瓣反流的发生与相对于基线的左心室舒张末期容积增加（58±3 vs. 62±3 ml）、二尖瓣环直径（2.4±0.1 vs. 2.4±0.1 cm）或覆盖乳头肌的左心室壁节段的室壁运动异常无关。相反，二尖瓣反流的发生伴随着整体左心室形状的显著变化，表现为收缩末期腔球形指数增加（0.22±0.02 vs. 0.30±0.01）（p<0.01）和收缩末期长轴/短轴比值降低（1.71±0.05 vs. 1.43±0.04）（p<0.001）。