高甲状腺素时快速心房激动对心房电生理特性的影响

目的：研究高甲状腺素水平时快速心房激动对心房电生理特性的影响。方法：将实验兔随机分为正常对照组（n=10）、起搏组（n=10）、甲亢组（n=14）和甲亢起搏组（n=12）。在基础状态和快速心房起博后2、4、6h，分别测定各组基础起搏周长为200ms、150ms、130ms时的心房有效不应期（AERP）。结果：起搏组快速起搏2、4、6h后的AERP明显小于基础状态和对照组（P〈0．01），甲亢组的AERP明显小于对照组（P〈0．01），甲亢起搏组快速起搏2、4、6h后的AERP明显小于基础状态（P〈0．01）和甲亢组（P〈0．05）。起搏组快速起搏2、4、6h后的AERP200-150和AERP200-130明显小于基础状态和对照组（P〈0．01），甲亢组和甲亢起搏组的AERP200-150和AERP200-130均明显小于对照组（P〈0．01），但甲亢组和甲亢起搏组的AERP200-150和AERP200-130无显著性差异（P〉0．05）。结论：高甲状腺素水平及在此基础上的短时间快速心房激动可引起心房电生理重构。

Effects of short-term rapid atrial pacing on electrophysiological charac-teristics of atrium in hyperthyroidism

Objective: To investigate the effects of short-term rapid atrial pacing on the electrophysiological characteristics of atrium in hyperthyroidism.Methods: Forty-six adult rabbits were randomly divided into 4 groups:normal control group(n=10),pacing group(n=10),hyperthyroidism group(n=14),hyperthyroidism/pacing group(n=12).Baseline AERP and AERPs after pacing 2,4,6 h were determined in all groups at driver cycle length(DCL) of 200 ms,150 ms and 130 ms.Results: In pacing group,AERPs at different DCL(200 ms,150 ms and 130 ms) were shortened after rapid pacing 2,4,6 h when compared with before pacing and control group(P<0.01).AERPs(at DCL of 200 ms,150 ms and 130 ms) in hyperthyroidism group were shorter than those in control group at all time points(P<0.01).AERPs(at DCL of 200 ms,150 ms and 130 ms) in hyperthyroidism/pacing group after rapid pacing 2,4,6 h were shorter than those in pacing 0 h(P<0.01) and hyperthyroidism group(P<0.05).AERP_(200-150)and AERP_(200-130)in pacing group after rapid pacing 2,4,6 h were significantly different from at pacing 0 h and control group(P<0.01).AERP_(200-150)and AERP_(200-130)in hyperthyroidism and hyperthyroidism/pacing group were significantly different from control group at all time points(P<0.01).No differences were observed in AERP_(200-150)and AERP_(200-130)between hyperthyroidism group and hyperthyroidism/pacing group.Conclusion: Hyperthyroidism and short-term atrial pacing in the presence of hyperthyroidism can lead to remodeling of atrial electrophysiology.