Moroe K, Annoura M, Matsuo K, Yamanouchi Y, Kumagai K, Arakawa K, Hiroki T
Department of Internal Medicine, Fukuoka University School of Medicine, Japan.
Cardiology. 1993;83(4):244-9. doi: 10.1159/000175977.
We examined the relationship between postpacing T wave changes and monophasic action potentials recorded from the ventricle in dogs. MAPs were recorded from the right and left ventricle before and after cessation of pacing. The duration of the MAP was calculated as the time in milliseconds from the upstroke to 90% repolarization (MAPD90). T waves in limb leads were flat or had a biphasic pattern, eventually becoming negative after pacing. The Q-T interval of the escape beat after pacing was prolonged compared with the control. After right ventricular pacing, the average duration of MAPD90 in the right ventricle, but not in the left ventricle, was prolonged. (right MAPD: control 275 +/- 10 ms; after pacing: 311 +/- 17 ms, p < 0.05; left MAPD: control: 266 +/- 23 ms, after pacing: 284 +/- 26 ms, NS). After left ventricular pacing, the average duration of MAPD90 in the left ventricle, but not in the right ventricle, was prolonged (right MAPD: control: 247 +/- 75 ms, after pacing: 287 +/- 39 ms, NS; left MAPD: control: 257 +/- 23 ms, after pacing: 303 +/- 25 ms, p < 0.05). Furthermore, the average duration of MAPD90 at the pacing site became progressively prolonged over time. These results suggest that myocardial cells retain the memory of abnormal repolarization associated with pacing.
我们研究了犬类心室起搏后T波变化与单极动作电位之间的关系。在起搏停止前后，分别记录右心室和左心室的单极动作电位（MAP）。MAP的持续时间计算为从上升支到复极化90%的时间（以毫秒为单位，即MAPD90）。肢体导联的T波呈平坦或双相模式，起搏后最终变为负向。起搏后逸搏的Q-T间期较对照组延长。右心室起搏后，右心室MAPD90的平均持续时间延长，而左心室未延长。（右心室MAPD：对照组275±10毫秒；起搏后：311±17毫秒，p<0.05；左心室MAPD：对照组：266±23毫秒，起搏后：284±26毫秒，无显著性差异）。左心室起搏后，左心室MAPD90的平均持续时间延长，而右心室未延长（右心室MAPD：对照组：247±75毫秒，起搏后：287±39毫秒，无显著性差异；左心室MAPD：对照组：257±23毫秒，起搏后：303±25毫秒，p<0.05）。此外，起搏部位的MAPD90平均持续时间随时间逐渐延长。这些结果表明，心肌细胞保留了与起搏相关的异常复极化记忆。
