用于校正运动期间心率变化所致QT间期的新型QT校正公式

Rabkin Simon W, Cheng XinBo Justin

Department of Medicine (Cardiology), University of British Columbia, Vancouver, BC, Canada.

Am J Med Sci. 2016 Feb;351(2):133-9. doi: 10.1016/j.amjms.2015.11.007.

BACKGROUND

The QT interval is a marker for drug-induced cardiac toxicity, electrolyte abnormalities and genetic mutations with a high risk of sudden death.

AIM

The objective was to determine the optimal QT-heart rate correction when heart rate is increased.

MATERIALS AND METHODS

A total of 40 persons had QT interval measured before at the end of each stage of a Bruce protocol. Currently used heart rate correction formulae (QTc) were compared to recently proposed QTc formulae derived from large population studies.

RESULTS

Comparing the data at each stage of exercise found that QTc using the Bazett formula (QTcBZT) increased with exercise while the QTc proposed by Fridericia (QTcFRD) and by Framingham (QTcFRM) decreased with exercise. In contrast QTc proposed by Dmitrienko (QTcDMT) and Rautaharju (QTcRTHa) were relatively constant despite the increase in heart rate during exercise, whereas QTc proposed by Hodges (QTcHDG) was more variable. With exercise, the differences between QTcBZT or QTcFRD and the other correction formulae became greater and highly significant. Next, the slope of QTc or RR regression was calculated for each individual during the exercise test. The rank order of the slopes (from the smallest to largest absolute value) was QTcRTHa, QTcDMT, QTcBZT, QTcHDG, QTcFRD and QTcFRM. Furthermore the slope of the QT/heart rate relationship was significantly (P < 0.0001) different between the older formulae proposed by Bazett or Fridericia compared to the newer formulae QTcDMT or QTcRTHa.

CONCLUSION

The 2 newer QT-heart rate correction formula should be used when evaluating QT interval at faster heart rates especially those associated with exercise.

背景

QT间期是药物性心脏毒性、电解质异常和具有猝死高风险的基因突变的一个标志物。

目的

目的是确定心率增加时的最佳QT-心率校正方法。

材料与方法

共有40人在Bruce方案各阶段结束时测量QT间期。将目前使用的心率校正公式（QTc）与最近从大规模人群研究中得出的QTc公式进行比较。

结果

比较运动各阶段的数据发现，使用Bazett公式的QTc（QTcBZT）随运动增加，而Fridericia提出的QTc（QTcFRD）和Framingham提出的QTc（QTcFRM）随运动降低。相比之下，Dmitrienko提出的QTc（QTcDMT）和Rautaharju提出的QTc（QTcRTHa）尽管在运动期间心率增加，但相对恒定，而Hodges提出的QTc（QTcHDG）变化更大。随着运动，QTcBZT或QTcFRD与其他校正公式之间的差异变得更大且具有高度显著性。接下来，在运动试验期间为每个个体计算QTc或RR回归的斜率。斜率的排序（从绝对值最小到最大）为QTcRTHa、QTcDMT、QTcBZT、QTcHDG、QTcFRD和QTcFRM。此外，与较新的公式QTcDMT或QTcRTHa相比，Bazett或Fridericia提出的较旧公式的QT/心率关系斜率存在显著差异（P < 0.0001）。