伊文思兰对兔左室心肌灌注范围显示效果及跨膜动作电位的影响

目的　探讨伊文思兰对于经冠脉灌注的兔左室心肌组织块灌注范围显示效果及跨膜动作电位的影响。方法　制做兔左心室游离壁楔形组织块 ,经回旋支持续灌注台式液。采用浮置的玻璃微电极同步记录内、中、外层心肌细胞跨膜动作电位并记录跨壁心电图。分析伊文思兰灌注前、灌注 30 min后组织块显色情况及不同频率刺激下内、中、外层跨膜动作电位时程和跨壁复极离散度的变化。结果　伊文思兰可清晰显示灌注范围 ,且 30 m in后颜色仍保持不变 ;在 5 0 0～ 4 0 0 0 ms刺激作用下 ,伊文思兰灌注前与灌注 30 m in后动作电位时程、跨壁复极离散度无显著变化 (P>0 .0 5 ) ,灌注过程中组织块无室性心律失常发生。结论　伊文思兰可以作为组织块灌注范围的显示剂

Effects of Evan Blue on Perfused Dimension Display and Rabbit Left Ventricular Action Potential

Objective Simultaneous recording of transmembrane action potential at endocardium, midcardium and epicardium and transmural ECG in arterially perfused left ventricular preparation is a new method for researching into the mechanism about ventricular arrhythmia, and in this connection, how to distinguish the perfused area plays a key role in keeping preparations under normal condition. This study is aimed to evaluate the effects of Evan Blue on the displaying of the perfused area and on the characters of transmembrane action potential of the arterially perfused left ventricular preparations. Methods Rabbit left ventricular wedge preparations were perfused with Tyrode solution continuously via left circumflex, and the action potential of endocardium, midmyocardium, epicardium or transmural electrocardiogram were recorded simultaneously. The action poatential duration (APD) , transmural dispersion of repolarization (TDR) or QT intervals were compared and the color variation of the preparations were studied before and 30 min after perfusion with Evan Blue. Results Under the basic stimulatory cycle length of 1000,2000, 4000 ms,there was no significant difference of APD in the same transmural layer or TDR before and after Evan Blue perfusion(P<0.01), but APD or TDR stimulated at basic cycle length of 1000-4000 ms were all higher than those recorded at 500 ms(P<0.01); APDs of endocardium were much longer than those of epicardium or midmyocardium (P<0.01); there was no significant difference in APD , TDR and QT intervals before and after Evan Blue perfusion (P>0.05). No premature ventricular contractions and ventricular tachycardia happened during the experiments. Conclusion Evan Blue can be used as a marker to identify the perfused area.