Use of lead adjustment formulas for QT dispersion after myocardial infarction.

Abstract

Lead adjustment formulas for QT dispersion are not appropriate in patients with myocardial infarction. Large differences in lead adjusted QTc dispersion are produced, dependent on the number of measurable leads, for very small differences in QTc dispersion. It is recommended that QT dispersion is presented as unadjusted QT and QTc dispersion, stating the mean (SD) of the number of leads in which a QT interval was measured.