Day C P, McComb J M, Matthews J, Campbell R W
Department of Academic Cardiology, Freeman Hospital, Newcastle upon Tyne, U.K.
Eur Heart J. 1991 Mar;12(3):423-7. doi: 10.1093/oxfordjournals.eurheartj.a059911.
Increased dispersion of ventricular recovery time is believed to be a substrate for serious ventricular arrhythmias. Class III antiarrhythmic drugs probably operate by decreasing dispersion through homogeneous prolongation of recovery time. A single surface QT value gives no information on recovery time dispersion but interlead variation in QT may be relevant. QTc dispersion was measured in 67 patients post myocardial infarction randomized to treatment with either sotalol or placebo. QTc dispersion was calculated as the difference between the maximum and minimum QTc in any surface electrocardiogram lead. Both maximum QTc and QTc dispersion varied considerably following infarction but throughout the 6-month follow-up period maximum QTc was significantly greater (P less than 0.05) and QTc dispersion significantly less (P less than 0.05) in patients on sotalol compared with placebo. These findings are in accord with expected changes in ventricular recovery time and provide strong support for the hypothesis that surface electrocardiogram QT variation reflects regional differences in ventricular recovery time.
心室复极时间离散度增加被认为是严重室性心律失常的一个基础。Ⅲ类抗心律失常药物可能通过均匀延长复极时间来减少离散度而起作用。单个体表QT值并不能提供关于复极时间离散度的信息，但QT间期的导联间差异可能与之相关。对67例心肌梗死后随机接受索他洛尔或安慰剂治疗的患者测量了QTc离散度。QTc离散度计算为任何体表心电图导联中最大QTc与最小QTc之间的差值。梗死发生后，最大QTc和QTc离散度均有相当大的变化，但在整个6个月的随访期内，与安慰剂相比，接受索他洛尔治疗的患者最大QTc显著更高（P<0.05），QTc离散度显著更低（P<0.05）。这些发现与心室复极时间的预期变化一致，并为体表心电图QT间期变化反映心室复极时间区域差异这一假说提供了有力支持。
