Extracellular detection of delayed afterdepolarization of cardiac fibers using signal averaging technique  

用细胞外信号叠加技术探测心肌纤维的延迟后除极<英文>

作　　者：解景田 TashaKLOWELL 袁钧苏 

机构地区：[1]Tang Center for Herbal Medicine Research, and Department of Anesthesia & Critical Care, The Pritzker School of Medicine, The University of Chicago, Chicago, IL 60637, USA

出　　处：《Acta Pharmacologica Sinica》2000年第11期19-27,共9页中国药理学报（英文版）

摘　　要：be detected using the extracellular electrograms combined with the high resolution, signal averaging technique.AIM: To detect delayed afterdepolarizations (DAD) in extracellular electrograms using signal averaging tech-nique. METHODS: DAD were induced by acetylstro-phanthidin (0.25 μmol·L-1, n = 9) and resibufogenin (0.52 μmol·L-1, n - 5) in sheep cardiac Purkinje fibers. Intracellular voltage was recorded with a conven-tional microelectrode, and simultaneous extracellular elec-trograms were recorded differentially from widely spaced electrodes placed in the tissue bath. Noise of electro-grams was reduced using signal averaging technique. RESULTS: Acetylstrophanthidin and resibufogenin both induced DAD in the intracellular recording and extracellu-lar DAD (DAD-E) in the extracellular electrogram in sheep heart Purkinje fibers. Acetylstrophanthidin and re-sibufogenin induced typical changes in the action potential including decrease in action potential amplitude, resting potential, maximum diastolic potential, and action poten-tial duration. Similar shortening occurred in the 'Q-T interval' recorded by the extracellular electrogram. With either acetylstrophanthidin or resibufogenin, shortening of stimulation cycle length from 990 ms to 690 ms reduced the coupling interval between action potential upstroke and peak voltage of the DAD (P < 0.01), and the cou-pling interval between the 'QRS' and DAD-E recorded extracellularly (P < 0.01). CONCLUSION: DAD can arrhythmia; electrophysiology; Purkin-je fibers; strophanthidin; bufanolides; computer-assisted; signal processing;目的:用信号叠加技术探测心肌细胞延迟后除极(DAD).方法:用乙酰毒毛花甙元(AS 0.25μmol/L,n=9)和脂布福吉宁(RBG 0.52μmol/L,n=5)诱发羊心肌浦氏纤维的DAD.胞内记录用常规微电极技术,胞外电图用一般电极技术.用信号叠加技术减少电图的噪声干扰.结果:AS和RBG均可诱发羊心肌浦氏纤维DAD,并可在胞内、外同时记录到.AS和RBG引发动作电位的典型改变包括降低振幅,减小静息电位和最大舒张期电位,缩短动作电位间期及Q-T间期.缩短刺激周长可缩短细胞内外记录的DAD的偶联间期(P<0.01).结论:用信号叠加技术可在细胞外探测心肌细胞DAD.

关 键 词：心律失常 电生理学 浦肯野氏纤维 毒毛旋花子甙元 蟾酥甾类 计算机辅助信号处理 

分 类 号：R541[医药卫生—心血管疾病]