Sutton P M, Taggart P, Lab M, Runnalls M E, O'Brien W, Treasure T
Department of Physiology, University College & Middlesex School of Medicine, London, U.K.
Eur Heart J. 1991 Jan;12(1):70-8. doi: 10.1093/oxfordjournals.eurheartj.a059828.
Electrophysiological alternans (beat-to-beat alternation of the configuration of the action potential and/or electrocardiogram) may be important in the causation of ventricular arrhythmias. We recorded monophasic action potentials from the left ventricular epicardium in patients undergoing routine cardiac surgery. We set out to determine: (a) whether a small increase in atrial pacing rate could elicit electrophysiological alternans; (b) whether different phases of the operation influence the incidence and; (c) whether electrical alternans was a localized phenomenon. Thirty-six patients were studied, and alternans of action potential duration was observed in 14 (39%). The difference between alternate long and short action potential durations ranged from 4 to 112 ms. The mean differences during each stage of the protocol were: pacing before bypass 33.3 +/- 22.7 ms (three of 17 patients); pacing after bypass 46.7 +/- 37.8 ms (nine of 36 patients); pacing during transient graft occlusion 28.0 +/- 23.1 ms (five of 17 patients); pacing following release of the grafts 29.6 +/- 30.0 ms (five of 17 patients). None of the patients showed any evidence of alternans in the electrocardiogram or mechanical alternans in radial artery pressure. In seven of the 14 patients showing alternans, recordings were made in closely adjacent (approximately 1 cm) areas showing that alternans could be a localized phenomenon. The findings indicate that electrical alternans was a frequent occurrence in this study (39% of patients) and may be a localized phenomenon.
电生理交替现象（动作电位和/或心电图形态的逐搏交替）可能在室性心律失常的发生中起重要作用。我们在接受常规心脏手术的患者的左心室心外膜记录了单相动作电位。我们旨在确定：（a）心房起搏频率的小幅增加是否会引发电生理交替现象；（b）手术的不同阶段是否会影响其发生率；以及（c）电交替现象是否为局部现象。对36例患者进行了研究，14例（39%）观察到动作电位时程的交替现象。交替出现的长、短动作电位时程之间的差异范围为4至112毫秒。方案各阶段的平均差异为：体外循环前起搏时为33.3±22.7毫秒（17例患者中的3例）；体外循环后起搏时为46.7±37.8毫秒（36例患者中的9例）；移植血管短暂阻断期间起搏时为28.0±23.1毫秒（17例患者中的5例）；移植血管开放后起搏时为29.6±30.0毫秒（17例患者中的5例）。所有患者均未显示心电图有任何交替现象的证据，桡动脉压力也未出现机械性交替现象。在出现交替现象的14例患者中的7例中，在相邻（约1厘米）区域进行了记录，表明交替现象可能是局部现象。研究结果表明，在本研究中电交替现象很常见（39%的患者），且可能是局部现象。
