Kamalvand K, Tan K, Lloyd G, Gill J, Bucknall C, Sulke N
Department of Cardiology, Guy's Hospital, London, U.K.
Eur Heart J. 1999 Jun;20(12):888-95. doi: 10.1053/euhj.1998.1404.
The purpose of this study was to determine the changes in atrial electrophysiology associated with chronic persistent atrial fibrillation in man.
Atrial monophasic action potential duration at 90% repolarization and the effective refractory period were measured in 13 patients with chronic persistent atrial fibrillation after low-energy endocardial cardioversion, and compared to eight controls without a history of atrial fibrillation. Measurements were made at the right atrial appendage and midlateral right atrial wall at basic, 600 ms and 400 ms drive cycle lengths. In control patients, the effective refractory periods were significantly longer at the atrial appendage than the lateral wall at 600 ms (right atrial appendage 265 ms, midlateral right atrial wall 228 ms, P<0.05), and 400 ms cycle lengths (right atrial appendage 270 ms, midlateral right atrial wall 218 ms, P<0.05), but this was not evident in patients with atrial fibrillation. The monophasic action potentials and effective refractory periods at both atrial sites were shorter in the atrial fibrillation patients compared to controls; however, only the effective refractory periods at atrial appendage at 600 ms (atrial fibrillation 210 ms, controls 265 ms, P<0.001), and 400 ms cycle lengths (atrial fibrillation 200 ms, controls 270 ms, P>0.001) reached statistical significance. Effective refractory period dispersion was significantly greater in controls than in patients with atrial fibrillation (cycle length 600 ms: controls 36, atrial fibrillation 13, P=0.01; cycle length 400 ms: controls 54, atrial fibrillation 18, P<0.01).
In patients without a history of atrial fibrillation, the refractory period at the right atrial appendage is significantly longer than at the midlateral right atrial wall. This 'normal' pattern of atrial refractory dispersion is lost in patients with chronic persistent atrial fibrillation, with marked shortening of the effective refractory period at the right atrial appendage. This may explain the high risk of recurrence of atrial fibrillation following successful electrical cardioversion.
本研究的目的是确定人类慢性持续性心房颤动相关的心房电生理变化。
在13例慢性持续性心房颤动患者接受低能量心内膜心脏复律后，测量其90%复极化时的心房单相动作电位持续时间和有效不应期，并与8例无房颤病史的对照者进行比较。在基础、600毫秒和400毫秒驱动周期长度下，于右心耳和右心房侧壁进行测量。在对照患者中，600毫秒（右心耳265毫秒，右心房侧壁228毫秒，P<0.05）和400毫秒周期长度时（右心耳270毫秒，右心房侧壁218毫秒，P<0.05），右心耳的有效不应期显著长于侧壁，但在房颤患者中并非如此。与对照组相比，房颤患者两个心房部位的单相动作电位和有效不应期均较短；然而，只有600毫秒（房颤组210毫秒，对照组265毫秒，P<0.001）和400毫秒周期长度时（房颤组200毫秒，对照组270毫秒，P>0.001）右心耳的有效不应期达到统计学意义。对照组的有效不应期离散度显著大于房颤患者（周期长度600毫秒：对照组36，房颤组13，P=0.01；周期长度400毫秒：对照组54，房颤组18，P<0.01）。
在无房颤病史的患者中，右心耳的不应期显著长于右心房侧壁。这种“正常”的心房不应期离散模式在慢性持续性房颤患者中消失，右心耳的有效不应期明显缩短。这可能解释了成功电复律后房颤复发的高风险。
