Sun H, Velipasaoglu E O, Berrier K L, Khoury D S
Department of Medicine, Baylor College of Medicine, Houston, Texas, USA.
Pacing Clin Electrophysiol. 1998 Nov;21(11 Pt 2):2500-5. doi: 10.1111/j.1540-8159.1998.tb01208.x.
Cavitary electrograms previously were measured from multiple directions simultaneously in the canine left ventricle with the use of noncontact multielectrode probes. The objective of the present study was to measure cavitary electrograms in the canine right atrium (RA) and describe the corresponding global activation sequences during normal and abnormal atrial rhythms. A 64-electrode custom probe was inserted into the RA of six dogs. Probe position and orientation were guided by fluoroscopy. Probe unipolar electrograms were acquired simultaneously during sinus rhythm, RA pacing, and ventricular pacing. Vagally mediated atrial fibrillation (AF) was induced in four dogs. Probe electrograms were acquired during AF induced at baseline and after intravenous infusion of ibutilide (0.075 mg/kg followed by 0.075 mg/kg infusion over 10 minutes). Isochrone maps were derived from noncontact probe electrograms and were displayed on a beat-by-beat basis during normal and paced rhythms. During AF, maps were displayed for 10 consecutive 100-ms windows. Isochrone maps of normal and paced beats revealed regions of early activation that were consistent with sites of wavefront initiation. During AF, multiple varying activation wavefronts were observed. At baseline, AF cycle length was 110 +/- 15 ms and the number of wavefronts was 1.72 +/- 0.25 per 100-ms window. After ibutilide, AF cycle increased to 182 +/- 36 ms (P = 0.018) and the number of wavefronts decreased to 0.82 +/- 0.14 per 100-ms window (P = 0.009). In conclusion, global electrophysiological imaging with a noncontact multielectrode probe delineates RA anatomy. Furthermore, images of AF activation depict multiple wandering wavefronts. Ibutilide reduces the number of these wavefronts and organizes AF.
以往使用非接触式多电极探头在犬类左心室中同时从多个方向测量心腔电图。本研究的目的是测量犬类右心房（RA）的心腔电图，并描述正常和异常心房节律期间相应的整体激动顺序。将一个64电极定制探头插入6只犬的右心房。探头位置和方向由荧光透视引导。在窦性心律、右心房起搏和心室起搏期间同时采集探头单极电图。在4只犬中诱发迷走神经介导的心房颤动（AF）。在基线时和静脉注射伊布利特（0.075mg/kg，随后在10分钟内输注0.075mg/kg）后诱发房颤期间采集探头电图。等时线图由非接触式探头电图得出，并在正常和起搏节律期间逐搏显示。在房颤期间，连续10个100毫秒窗口显示图谱。正常和起搏搏动的等时线图显示了与波前起始部位一致的早期激动区域。在房颤期间，观察到多个变化的激动波前。基线时，房颤周期长度为110±15毫秒，每100毫秒窗口的波前数量为1.72±0.25。伊布利特治疗后，房颤周期增加至182±36毫秒（P = 0.018），每100毫秒窗口的波前数量减少至0.82±0.14（P = 0.009）。总之，使用非接触式多电极探头进行的整体电生理成像描绘了右心房的解剖结构。此外，房颤激动图像显示了多个游走的波前。伊布利特减少了这些波前的数量并使房颤变得规整。
