Daoud E G, Pariseau B, Niebauer M, Bogun F, Goyal R, Harvey M, Man K C, Strickberger S A, Morady F
Department of Internal Medicine, University of Michigan, Ann Arbor 48109-0022, USA.
Circulation. 1996 Sep 1;94(5):1036-40. doi: 10.1161/01.cir.94.5.1036.
High-density mapping studies of atrial fibrillation (AF) have suggested the presence of an excitable gap. The purpose of this study was to assess the local and left atrial response to pacing at the high right atrium during type I AF in humans.
Pacing was performed at the high right atrium during type I AF in 24 patients in the electrophysiology laboratory. The response to pacing was assessed at cycle lengths 10, 20, 30, 40, and 50 ms less than the mean baseline atrial cycle length. Digitized tracings of the baseline tachycardia and the response to pacing were recorded from the high right atrium and from the distal coronary sinus. Computer analysis of these signals was used to calculate a left atrial electrogram density before, during, and after pacing. Two hundred eight-eight segments of AF with a duration of 3.9 +/- 0.5 seconds (mean +/- SD) were analyzed. Local capture of the right atrium during AF was demonstrated for at least one pacing cycle length in each patient. The left atrial electrogram density was significantly greater than baseline at each pacing cycle length that resulted in local capture, except when pacing at 50 ms less than the mean AF cycle length. There was no significant change in the baseline left atrial electrogram density compared with baseline when pacing did not result in local capture of AF.
Local right atrial capture is often possible by pacing during type I AF and consistently influences the left atrial electrograms recorded in the coronary sinus. These results confirm the presence of excitable tissue in the right and left atria in type I AF.
心房颤动（AF）的高密度标测研究提示存在可兴奋间隙。本研究的目的是评估人类I型房颤期间高位右心房起搏时的局部及左心房反应。
在24例患者的电生理实验室中，于I型房颤期间在高位右心房进行起搏。在比平均基线心房周期长度短10、20、30、40和50毫秒的周期长度下评估起搏反应。从高位右心房和远端冠状窦记录基线心动过速及起搏反应的数字化描记图。对这些信号进行计算机分析，以计算起搏前、起搏期间和起搏后的左心房电图密度。分析了288段持续时间为3.9±0.5秒（平均±标准差）的房颤。在每位患者中，均证实房颤期间右心房至少在一个起搏周期长度内实现了局部夺获。在导致局部夺获的每个起搏周期长度下，左心房电图密度均显著高于基线，但在比平均房颤周期长度短50毫秒进行起搏时除外。当起搏未导致房颤的局部夺获时，与基线相比，基线左心房电图密度无显著变化。
在I型房颤期间起搏常常能够实现右心房局部夺获，并持续影响在冠状窦记录到的左心房电图。这些结果证实了I型房颤时右心房和左心房中存在可兴奋组织。
