Optical study on the generation of experimental arrhythmias with re-entry of the excitatory waves

采用电压敏感染料和多元件光电二极管阵列多点光学记录跨膜电压活动，监测大鼠心房的心动过速样兴奋。从成年大鼠心脏解剖的心房制备物用部花青-若丹宁染料（NK 2761）染色，并从多个部位同时记录动作电位。我们使用含有2，3-丁二酮单肟（20 mM）的沐浴介质，以减少收缩相关的光散射。通过一系列电刺激（5-20 Hz/ 1-2 sec）或用双极电极施加的0.5-1 Hz的常规刺激诱发具有约250 - 450 ms周期长度的心动过速样兴奋。这些事件持续不同的时间段（10秒-超过10分钟），通常自发终止。兴奋的传播进行了光学评估，我们映射的兴奋波的传导模式。这些图表明，兴奋波往往在一个准圆形的途径，往往包围了上级腔静脉口传播。然而，也观察到其他几种模式，如无解剖障碍的“阻塞区”，起搏活动的异位病灶和具有多个波前的更复杂的模式。

Multiple-site optical recordings of transmembrane voltage activity, using a voltage-sensitive dye and a multi-element photodiode array, were employed to monitor the tachycardia-like excitation in the rat atrium. Atrial preparations dissected from adult rat hearts were stained with a merocyanine-rhodanine dye (NK2761), and the action potentials were recorded simultaneously from many sites. We used a bathing medium containing 2,3-butanedione monoxime (20 mM) to reduce the contraction-related light scattering. The tachycardia-like excitation with a cycle length of about 250 - 450 ms was evoked either by a train of electrical stimuli (5-20 Hz/ 1-2 sec) or regular stimuli of 0.5-1 Hz applied with bipolar electrodes. The events lasted for various time periods (10 sec - over 10 min) and often terminated spontaneously. The spread of excitation was assessed optically, and we mapped the conduction patterns of the excitatory waves. These maps indicate that the excitatory waves often propagated in a quasi-circular pathway which often surrounded the ostium of the superior vena cava. However, several other patterns, such as "blocked areas" without anatomical obstacle, ectopic foci of pacemaking activity and more complex patterns with multiple wavefront, were also observed.