运动猪左前降支冠状动脉狭窄所致的心室间冠状动脉窃血

Interventricular coronary steal induced by stenosis of left anterior descending coronary artery in exercising pigs.

作者信息

Crottogini A J, Guth B D, Barra J G, Willshaw P, Lascano E C, Pichel R H

机构信息

Research and Teaching Department, Favaloro Foundation, Buenos Aires, Argentina.

出版信息

Circulation. 1991 Apr;83(4):1361-70. doi: 10.1161/01.cir.83.4.1361.

DOI:10.1161/01.cir.83.4.1361

PMID:2013153

Abstract

BACKGROUND

In pigs and humans, the left anterior descending coronary artery (LAD) supplies the left ventricular anterior wall (LVAW), anterior septum, and paraseptal band of the right ventricular anterior wall (RVAW). The purposes of our study were 1) to study the LAD flow distribution in these walls during preexercise, exercise, and exercise with LAD stenosis and 2) to analyze regional wall motion under these conditions.

METHODS AND RESULTS

Nine pigs were instrumented with sonomicrometers for measuring percent wall thickening (%WTh) in LVAW, RVAW, and lateral (control) walls of both ventricles, a hydraulic occluder at the LAD origin, an LV pressure transducer, and catheters for radioactive microsphere injection (left atrium) and blood withdrawal (aorta). One month later, regional %WTh and flows were measured during preexercise, exercise, and continuing exercise with LAD stenosis resulting in more than 50% reduction in systolic LVAW %WTh with regard to exercise. LAD stenosis caused a dramatic decrease in total mean +/- SD LVAW subendocardial flow with regard to exercise (28.7 +/- 8 to 9.1 +/- 3.2 ml.min-1, p less than 0.0001) but not significant changes in either LVAW subepicardial flow or RVAW flow. The transmural distribution of flows within the LAD bed (as percentages of the total LAD flow in each experimental condition) showed that LAD stenosis redistributed flows with regard to exercise such that the LVAW subendocardial flow decreased from 26.4 +/- 4.2% of the total LAD flow to 11.8 +/- 4.3% (p less than 0.0001), whereas LVAW subepicardial flow increased from 32.9 +/- 2.3% of the total LAD flow to 45.5 +/- 7.9% (p less than 0.0001) and RVAW increased from 12 +/- 4.9% of the total LAD flow to 18.7 +/- 7.2% (p less than 0.0005). With exercise plus LAD stenosis, LVAW %WTh decreased from 43.2 +/- 8.4% to 17.2 +/- 9.7% (p less than 0.0001), but RVAW %WTh did not change.

CONCLUSIONS

In the LAD bed of exercising pigs, LAD stenosis induces, in addition to transmural steal, an interventricular steal favoring the RVAW at the expense of the LVAW subendocardium. This steal results in preserved RVAW thickening despite severe LVAW hypokinesia.

摘要

背景

在猪和人类中，左冠状动脉前降支（LAD）为左心室前壁（LVAW）、前间隔以及右心室前壁（RVAW）的旁间隔带供血。我们研究的目的是：1）研究运动前、运动期间以及LAD狭窄时运动状态下这些心肌壁中的LAD血流分布；2）分析这些情况下的局部心肌壁运动。

方法与结果

对9头猪进行仪器植入，通过超声微测仪测量左、右心室的LVAW、RVAW和外侧（对照）心肌壁的心肌增厚百分比（%WTh），在LAD起始处放置一个液压封堵器，植入左心室压力传感器，以及用于放射性微球注射（左心房）和采血（主动脉）的导管。1个月后，在运动前、运动期间以及LAD狭窄导致收缩期LVAW的%WTh相对于运动时降低超过50%的持续运动期间，测量局部%WTh和血流。与运动相比，LAD狭窄导致LVAW心内膜下总平均±标准差血流显著减少（从28.7±8降至9.1±3.2 ml·min-1，p<0.0001），但LVAW心外膜下血流或RVAW血流均无显著变化。LAD供血区血流的透壁分布（以每种实验条件下LAD总血流的百分比表示）显示，与运动相比，LAD狭窄使血流重新分布，使得LVAW心内膜下血流占LAD总血流的比例从26.4±4.2%降至11.8±4.3%（p<0.0001），而LVAW心外膜下血流占LAD总血流的比例从32.9±2.3%增至45.5±7.9%（p<0.0001），RVAW血流占LAD总血流的比例从12±4.9%增至18.7±7.2%（p<0.0005）。运动加LAD狭窄时，LVAW的%WTh从43.2±8.4%降至17.2±9.7%（p<0.0001），但RVAW的%WTh未改变。