REDISTRIBUTION OF MYOCARDIAL FIBER STRAIN AND BLOOD-FLOW BY ASYNCHRONOUS ACTIVATION
REDISTRIBUTION OF MYOCARDIAL FIBER STRAIN AND BLOOD-FLOW BY ASYNCHRONOUS ACTIVATION
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DOI：
10.1152/ajpheart.1990.259.2.h300
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发表时间：
1990-08-01
影响因子：
--
通讯作者：
RENEMAN, RS
中科院分区：
文献类型：
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作者：
PRINZEN, FW;AUGUSTIJN, CH;RENEMAN, RS
11只麻醉开胸犬的心脏从右心房（RA）、右心室流出道（RVOT）和左心室心尖（LVA）起搏。在左室前壁15- 20cm2区域内获得心外膜层的电激活序列图（192个电极）、纤维应变图（视频技术）和血流图（微球技术）。该区域的电不同步度为10。5 (ra) 52 .+-。12 （RVOT）和30 .+-。16ms （LVA，平均值+-）。RVOT和LVA与RA比较，SD, P < 0.05)。射血期心外膜纤维张力在RA起搏期间分布均匀。然而，在心室起搏期间，它的范围从13。33% RVOT)和23% +-。RA起搏早期激活区LVA值降低29%至268 +-。127% （RVOT）和250。在晚激活的区域是这个值的130% （LVA）。心外膜血流量从81。22 （RVOT）和79 .+-。23% （LVA）早激活区至142 .+-。42 （RVOT）和126 .+-。22% （LVA）在后期激活区。以上数值与RA比较P < 0.05。在RVOT起搏过程中，心外膜电激活时间、纤维张力和血流量的梯度指向相同的方向。与RVOT起搏相比，LVA起搏时各梯度方向相反，时间和血流的电激活梯度较小。这些结果表明，电激活的时间是左心室壁纤维张力和血流分布的重要决定因素。
Hearts of 11 anesthetized open-chest dogs were paced from the right atrium (RA), right ventricular outflow tract (RVOT), and left ventricular apex (LVA). Maps of the sequence of electrical activation (192 electrodes), fiber strain (video technique), and blood flow (microsphere technique) in the epicardial layers were obtained from a 15- to 20-cm2 area of the anterior left ventricular wall. Electrical asynchrony in this area was 10 .+-. 5 (RA), 52 .+-. 12 (RVOT), and 30 .+-. 16 ms (LVA, means .+-. SD, P < 0.05) for RVOT and LVA compared with RA). Epicardial fiber strain during the ejection phase was uniformly distributed during RA pacing. However, during ventricular pacing it ranged from 13 .+-. 33% RVOT) and 23 .+-. 29% (LVA) of the value during RA pacing in early-activated regions to 268 .+-. 127% (RVOT) and 250 .+-. 130% (LVA) of this value in late-activated regions. Epicardial blood flow ranged from 81 .+-. 22 (RVOT) and 79 .+-. 23% (LVA) in early-activated regions to 142 .+-. 42 (RVOT) and 126 .+-. 22% (LVA) in late activated regions. In all above values P < 0.05 compared with RA. During RVOT pacing, gradients of epicardial electrical activation time, fiber strain, and blood flow pointed in the same direction. Compared with RVOT pacing, during LVA pacing all gradients were opposite in direction, and the gradients of electrical activation of time and blood flow appeared to be smaller. These results indicate that timing of electrical activation is an important determinant for the distribution of fiber strain and blood flow in the left ventricular wall.