Discussion on Bivariate Reference Ranges of QT Interval and Heart Rate

摘要

The QT interval (QT, a measure of the time between the start of the Q wave and the end of the T wave) is an important factor in cardiology. The QT is dependent on the heart rate (HR). The faster the HR is, the shorter is the QT. The commonly used bazett’s , Fredericia’s and Framingham’s correction formula calculating the HR-corrected QT interval QTc, QTf and QTLc respectively, have the defects of inaccuracy or simple function form incapable of showing QT and HR’s complex physiological relationship. To establish diagnosis standard of QT and HR, the method of bivariate reference range of QT and HR using Mahalanobis statistical depth function was developed based on 415 normal young volunteers (male 183, female 233) , which is called QTMc. Its advantage is that the correlation matrix of QT and HR is used to express the complex relationship between them. It performs better theoretically.