Validation of automatic measurement of QT interval variability

Validation of automatic measurement of QT interval variability

BACKGROUND Increased variability of beat-to-beat QT-interval durations on the electrocardiogram (ECG) has been associated with increased risk for fatal and non-fatal cardiac events. However, techniques for the measurement of QT variability (QTV) have not been validated since a gold standard is not available. In this study, we propose a validation method and illustrate its use for the validation...

QT Interval and QT Variability

QT interval measurement: evaluation of automatic QTc measurement and new simple method to calculate and interpret corrected QT interval.

BACKGROUND Assessment of repolarization duration is often recommended to avoid administration of QT-prolonging drugs in patients with prolonged QTc interval, a frequent situation in the postoperative period. Bazett QT correction inappropriately increases QTc when heart rate is increased, and the use of the Fridericia formula may avoid a falsely prolonged QTc interval. The authors assessed autom...

Measurement of the QT interval.

Ventricular repolarization is reflected by the T-wave of the surface electrocardiogram, the QT interval being the time taken for ventricular recovery. QT measurement has assumed clinical importance as prolongation is associated with a variety of conditions includingthe Romano-Ward' and JervellLange-Neilson syndromes, drug toxirity' and an adverse prognosis following acute myocardial infarction....

Issues in QT interval measurement

The QT interval, apart from clinical implications is crucial for safety assessment of new drugs under development. A QTc prolongation of even 10 msec in a study group is a warning signal for a new drug. There are various issues involved in the measurement of the QT interval especially regarding the ending of the T wave and different morphological pattern of T-U complex. The other issue is signi...