Reciprocal functional interaction of adjacent myocardial segments during regional ischemia: an intraventricular loading phenomenon affecting apparent regional contractile function in the intact heart.
Reciprocal functional interaction of adjacent myocardial segments during regional ischemia: an intraventricular loading phenomenon affecting apparent regional contractile function in the intact heart.
复制标题
区域缺血期间相邻心肌节段的相互功能相互作用：影响完整心脏中明显区域收缩功能的心室内负荷现象。
DOI：
10.1016/s0735-1097(86)80155-3
复制
发表时间：
1986
影响因子：
24
通讯作者：
Desmond,J
中科院分区：
文献类型：
--
作者：
Smalling,RW;Ekas,RD;Felli,PR;Binion,L;Desmond,J
与局部缺血相邻的心肌节段功能增加的机制尚不清楚。为了研究区域负荷变化是这一现象的重要原因的假设，17只犬在左前降支和回旋支动脉分布中使用节段性缩短声测微计，回旋支冠状动脉流量探头和袖带封堵器，以及回旋支冠状动脉压力导管。此外，动物有主动脉压力导管和心室压力微压计。该动物模型允许通过局部缺血或给予异丙肾上腺素来调节局部变力状态，在回旋支冠状动脉床缺血时，回旋支分布的节段性缩短从11.9%降低到6.3%（p = 0.001），而左前降支区域性缩短从11.6%增加到13.4%（p < 0.001）。这些相互的变化发生在全球后负荷或心率变化的情况下。全身β受体阻断剂并没有改变这种反应，这表明它不是反射或儿茶酚胺介导的。冠状动脉回旋支注入异丙肾上腺素导致回旋支区域缩短从12.5%增加到17.4%左前降支区域性短缩从13.5%下降到8.3%（P < 0.02）（p < 0.001），这些数据表明，心脏相邻的心脏之间的相互作用，心肌节段的变化是局部后负荷变化的结果，局部前负荷和射血时间的变化也有助于观察到的效果。
The mechanism of the increase in function in myocardial segments adjacent to those subjected to regional ischemia is not known. To investigate the hypothesis that changes in regional loading are an important causative factor of this phenomenon, 17 dogs were instrumented with segmental shortening sonomicrometers in the left anterior descending and circumflex artery distributions, circumflex coronary flow probes and cuff occluders, as well as circumflex coronary pressure catheters. Additionally, the animals had aortic pressure catheters and ventricular pressure micromanometers. This animal model allowed modulation of regional inotropic state with regional ischemia or isoproterenol administration.With circumflex coronary bed ischemia, segmental shortening in the circumflex distribution decreased from 11.9 to 6.3% (p = 0.001) whereas left anterior descending regional shortening increased from 11.6 to 13.4% (p < 0.001). These reciprocal changes occurred in the absence of changes in global afterload or heart rate. Systemic beta-receptor blockade did not change this reponse, suggesting that it was not reflex- or catecholamine-mediated. Infusing isoproterenol into the circumflex coronary artery resulted in an increase in circumflex regional shortening from 12.5 to 17.4% (p < 0.02) whereas left anterior descending regional shortening decreased from 13.5 to 8.3% (p < 0.001), again without change in heart rate or left ventricular or aortic pressure.These data suggest that reciprocal functional interaction between adjacent myocardial segments is a result of changes in regional afterload for the most part, with changes in local preload and timing of ejection also contributing to the observed effect.