Fei L, Slade A K, Grace A A, Malik M, Camm A J, McKenna W J
Department of Cardiological Sciences, St. George's Hospital Medical School, London, United Kingdom.
Pacing Clin Electrophysiol. 1994 Nov;17(11 Pt 2):2222-7. doi: 10.1111/j.1540-8159.1994.tb03830.x.
This study aims to assess the dynamics of the QT interval in patients with hypertrophic cardiomyopathy (HCM). Three consecutive QT intervals and the preceding RR intervals were measured on 24 hour ambulatory electrocardiograms at 30-minute intervals in ten high risk patients with HCM (sudden cardiac death [SCD] and/or documented ventricular fibrillation), aged 29 +/- 17 years, compared with ten age and sex matched low risk patients with HCM (no syncope, no adverse family history, and no ventricular tachycardia on Holter monitoring), and ten normal subjects. Another ten patients who were on amiodarone therapy (200-mg daily) were also studied. Patients with intraventricular conduction defects were excluded. There were 4,424 pairs of QT intervals and their preceding RR intervals were measured in this study. A nonsignificant prolongation in the QT interval and a significant prolongation in QTc values (Bazett's and Fridericia's formulas) were demonstrated in patients with HCM compared with normals. There were no significant differences in the QT and QTc between high and low risk patients. The slope of regression line for the QT against RR interval was significantly different between normals and HCM (0.1583 +/- 0.040 vs. 0.2017 +/- 0.043, P < 0.05), but not between high and low risk patients. Amiodarone significantly prolonged the QT and QTc without significantly altering the slope of the regression line (0.2017 +/- 0.043 vs 0.2099 +/- 0.037, NS). Our findings support the observations that there is a prolonged QT interval in patients with HCM and that there is no significant use dependent effect of amiodarone on ventricular repolarization.(ABSTRACT TRUNCATED AT 250 WORDS)
本研究旨在评估肥厚型心肌病（HCM）患者QT间期的动态变化。在10例高危HCM患者（心脏性猝死[SCD]和/或记录到心室颤动）中，每隔30分钟在24小时动态心电图上测量连续3个QT间期及其前的RR间期，这些患者年龄为29±17岁，将其与10例年龄和性别匹配的低危HCM患者（无晕厥、无不良家族史且动态心电图监测无室性心动过速）以及10例正常受试者进行比较。另外10例接受胺碘酮治疗（每日200毫克）的患者也被纳入研究。排除有室内传导阻滞的患者。本研究共测量了4424对QT间期及其前的RR间期。与正常受试者相比，HCM患者的QT间期延长不显著，但QTc值（采用Bazett公式和Fridericia公式）显著延长。高危和低危患者之间的QT及QTc无显著差异。正常人与HCM患者QT与RR间期回归线的斜率显著不同（0.1583±0.040对0.2017±0.043，P<0.05），但高危和低危患者之间无差异。胺碘酮显著延长了QT和QTc，但未显著改变回归线的斜率（0.2017±0.043对0.2099±0.037，无显著性差异）。我们的研究结果支持以下观点：HCM患者存在QT间期延长，且胺碘酮对心室复极无显著的使用依赖性效应。（摘要截短于250字）
