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Published on: August 1, 2019
A proposed method for the calculation of age-dependent QRS duration z-scores
Henry Chubb1, Scott R Ceresnak2, Kara S Motonaga2
1Division of Pediatric Cardiology, Department of Pediatrics, Stanford University, Palo Alto, CA, USA; Department of Cardiothoracic Surgery, Stanford University School of Medicine, 780 Welch Road, Stanford, CA 9430, USA.
Background:
There are currently no published algorithms for calculation of age-dependent QRS duration z-scores. The absence of a standardized measure has limited researchers' abilities to compare ECG measurements of electrical synchrony between subjects of different ages or longitudinally over time.
Methods:
Four existing studies of normal ECG measurements (total 19,062 subjects) were used to estimate age and sex-dependent means and standard deviations.
Results:
Weighted means and standard deviations were best estimated by cubic functions to create z-score algorithms.
Conclusion:
Nomograms and algorithms for QRS duration z-scores may be estimated to compare ECG findings in both children and adults.
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