Dumcius Arimantas, Bavarskis Egidijus, Bytautas Algimantas, Chekanov Valeri
Institute of Biomedical Research of Kaunas Medical University, Kaunas, Lithuania.
ASAIO J. 2003 Jul-Aug;49(4):486-91.
Our previous investigations in a sheep model demonstrated that when electrical stimulation (ES) was applied to a newly mobilized latissimus dorsi muscle (LDM) in a work-rest regimen and at a rate of 15 contractions per minute, it did not damage this muscle. This regimen was used twice during a 60 minute period, once a day for 16 days, with no LDM damage. The goal of our current investigation was to apply this regimen in studies of acute thoracic aortomyoplasty. In two experimental groups, we mobilized the LDM but left it in situ. Two hours later, contractile force (CF) testing (20 g/kg preload, six impulses per burst) was performed until CF dropped to 50% of baseline. Recovery time needed to completely restore CF was calculated. In one group (six sheep), we applied continuous ES; in another (six sheep), we applied ES in a work-rest regimen (1 min work, 1 min rest). In two other groups of six dogs each, aortomyoplasty was performed; the LDM flap was subjected to ES immediately postoperatively (six impulses per burst; ventricular-LDM delay, 290 ms). Again, one group received continuous ES, and the other received work-rest ES. In the mobilized LDM under continuous ES, CF decreased to 50% of baseline values after 52 +/- 8 minutes, and returned to baseline after 84 +/- 16 minutes of rest. Under the work-rest regimen, this decrease took 105 +/- 8 minutes, and the return to baseline took 25 +/- 6 minutes (p < 0.05). In LDM subjected to work-rest ES, light microscopy revealed no additional damage to LDM tissue than was seen immediately after mobilization. However, LDM subjected to continuous ES had evidence of increased basophilic degeneration and wavy fibers. After acute thoracic aortomyoplasty, assisted hemodynamic values under the continuous ES exceeded unassisted values for only 40 minutes, compared with 100 minutes for work-rest ES (p < 0.05). When counterpulsation was completed, for continuous ES, recovery time to baseline was 96 +/- 9 minutes; for work-rest ES, it was only 43 +/- 6 minutes. In conclusion, a work-rest regimen of ES can be started safely immediately postprocedure.
我们之前在绵羊模型中的研究表明，当以每分钟15次收缩的频率，在工作-休息方案下对新动员的背阔肌（LDM）施加电刺激（ES）时，不会损伤该肌肉。在60分钟内该方案使用两次，每天一次，共16天，未出现LDM损伤。我们当前研究的目标是将该方案应用于急性胸主动脉成形术的研究中。在两个实验组中，我们动员了LDM但将其留在原位。两小时后，进行收缩力（CF）测试（预负荷20 g/kg，每次爆发6次脉冲），直至CF降至基线的50%。计算完全恢复CF所需的恢复时间。在一组（6只绵羊）中，我们施加持续ES；在另一组（6只绵羊）中，我们以工作-休息方案（工作1分钟，休息1分钟）施加ES。在另外两组各有6只狗的实验中，进行了主动脉成形术；术后立即对LDM皮瓣施加ES（每次爆发6次脉冲；心室-LDM延迟290 ms）。同样，一组接受持续ES，另一组接受工作-休息ES。在持续ES下的动员LDM中，CF在52±8分钟后降至基线值的50%，休息84±16分钟后恢复到基线。在工作-休息方案下，这种下降需要105±8分钟，恢复到基线需要25±6分钟（p<0.05）。在接受工作-休息ES的LDM中，光学显微镜检查显示，与动员后立即观察到的情况相比，LDM组织没有额外损伤。然而，接受持续ES的LDM有嗜碱性变性增加和纤维呈波浪状的证据。急性胸主动脉成形术后，持续ES下的辅助血流动力学值仅在40分钟内超过非辅助值，而工作-休息ES为100分钟（p<0.05）。当反搏完成时，持续ES恢复到基线的时间为96±9分钟；工作-休息ES仅为43±6分钟。总之，ES的工作-休息方案可在术后立即安全启动。
