Regular paperAssessment of prolonged QT and JT intervals in ventricular conduction defects☆
Section snippets
Study population
Source data for this investigation were derived from 3 different population studies previously described in detail: the Third National Health and Nutrition Examination Survey,3 the Cardiovascular Health Study,4 and the Atherosclerosis Research In Communities Study.5 Subjects with a history of heart attack, coronary bypass surgery, or coronary angioplasty were excluded. Electrocardiographically based exclusions for the group with normal conduction included a QRS interval ≥120 ms and other major
Results
The first relevant point to consider is the possible adequacy of the use of QTc − QRS, appropriately denoted as JTc for rate adjustment. The plot of JTc versus ventricular rate in the VCD group (Figure 1) shows that this adjustment retained a profound dependence of the adjusted JT interval on ventricular rate, with a high residual correlation (r = 0.54). This level of residual correlation was even higher than in subjects with normal ventricular conduction (r = 0.32).3
In considering possible
Discussion
A critical result from the present investigation was that QT adjustment in VCDs obtained as QTc − QRS retained a strong residual correlation with ventricular rate (r = 0.54). The correlation was even larger than that for QTc in normal conduction (r = 0.32).3 This renders the use of QTc − QRS in VCDs as disadvantageous, and its potential retention of risk information2 does not remove its fundamental flaws by statistical manipulations. In contrast, QT adjustment for VCD as QTRR,QRS = QT − 155 ×
Acknowledgements
The investigators thank the staff and participants in the Atherosclerosis Research In Communities Study and the Cardiovascular Health Study for their important contributions. For the full list of participating investigators and institutions in the Cardiovascular Health Study, see About CHS: Principal Investigators and Study Sites at http://chs3.biostat.washington.edu/chs. Atherosclerosis Research In Communities research members are listed in reference 5.
References (11)
QT interval and repolarization time in patients with intraventricular conduction delay
J Electrocardiol
(1990)- et al.
The Cardiovascular Health Study. Design and rationale
Ann Epidemiol
(1991) - et al.
A standardized procedure for locating and documenting ECG chest electrode positions. Consideration of the effect of breast tissue on ECG amplitudes in women
J Electrocardiol
(1998) - et al.
Prognostic significance of corrected QT and corrected JT interval for incident CHD in a general population sample stratified by presence or absence of wide QRS complexthe ARIC Study with 13 years follow-up
Circulation
(1993) - et al.
Linearly scaled, rate-invariant normal limits for QT interval. Eight decades of incorrect application of power functions
J Cardiovasc Electrophysiol
(2002)
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This study was supported by contracts NO1-HC-15103, NO1-HC-35129, NO1-HC-55015, NO1-HC-55016, NO1-HC-55018 through NO1-HC-55022, and NO1-HC-85079 through NO1-HC-85086 from the National Heart, Lung, and Blood Institute, Bethesda, Maryland.