Department of Physiology, Cardiovascular Division, Federal University of São Paulo (UNIFESP), Brazil.
J Card Fail. 2009 Aug;15(6):540-8. doi: 10.1016/j.cardfail.2009.01.007. Epub 2009 Mar 17.
The purpose of the current study was to create a model of myocardial infarction (MI) that is homogeneous in size with a low immediate (24 hours) mortality.
Male and female rats (n = 256) underwent left ventricle (LV) ablation (Ab) by a radiofrequency current (1000 kHz; 12 watts for 12 seconds) to promote a MI. A transmural MI occurred in all rats. Post-Ab complex arrhythmias were frequent (atrioventricular block, ventricular tachycardia, and fibrillation), which rapidly and spontaneously reverted to sinus rhythm. Among 66 male rats, immediate mortality occurred in 7.5%. Small MI size dispersion was characterized by smaller variability following Ab (x +/- SD: 45 +/- 8%) when compared with coronary occlusion (Oc; 40 +/- 19%). The histopathologic evaluations identified lesions similar to those which occurred following Oc, with scarring complete at 4 weeks. The hemodynamic and Doppler echocardiograms showed comparable increases in LV dimension, end-diastolic pressure, and pulmonary water content 1 and 4 weeks post-MI. Papillary muscle mechanics 6 weeks post-MI had matched inotropic and lusitropic dysfunction.
LV Ab gave rise to a MI within a narrow size limit and with a low immediate mortality. LV Ab resulted in histopathologic evolution, ventricular dilation, and dysfunction, impairment in myocardial mechanics, and congestive outcome that reproduced a MI from Oc.
本研究的目的是建立一种大小均一且即刻（24 小时）死亡率较低的心肌梗死（MI）模型。
雄性和雌性大鼠（n=256）接受左心室（LV）消融（Ab），采用射频电流（1000 kHz；12 瓦 12 秒）以促进 MI。所有大鼠均发生透壁性 MI。Ab 后常出现复杂的心律失常（房室传导阻滞、室性心动过速和颤动），这些心律失常迅速且自发地恢复为窦性节律。在 66 只雄性大鼠中，即刻死亡率为 7.5%。与冠状动脉闭塞（Oc）相比，Ab 后 MI 大小的离散度较小（x +/- SD：45 +/- 8%），这表明 MI 大小的离散度较小。组织病理学评估发现病变与 Oc 后发生的病变相似，4 周时完全形成瘢痕。血流动力学和多普勒超声心动图显示，MI 后 1 周和 4 周时 LV 内径、舒张末期压力和肺水含量均有相似程度的增加。MI 后 6 周时，乳头肌力学出现匹配的变力性和松弛性功能障碍。
LV Ab 导致 MI 的大小限制在较窄的范围内，且即刻死亡率较低。LV Ab 导致组织病理学演变、心室扩张和功能障碍、心肌力学受损以及充血性结局，与 Oc 引起的 MI 相似。
