2022年12月26日 · QTc is prolonged if it is greater than 440 ms in men or greater than 460 ms in women. A QTc greater than 500 is associated with an increased risk of torsade de pointes. While several equations exist to help correct heart rate variation, the Bazett formula (QTC = QT / √ RR) is the most commonly used.

From a screening perspective, a QTc value ≥470 ms for a 2–4-week-old infant screening programme or a QTc ≥500 ms in adolescents/adults may represent far more optimal “penalty box” screening values with an estimated positive predictive value >50%.

Learn about QT time (duration), corrected QT (QTc) duration, with emphasis on ECG features and risk of arrhythmia (e.g LQTS).

2018年8月23日 · In this study, we present the results of a large cohort of LQTS patients and controls with a comprehensive evaluation of QTc cutoff values specified for QT interval measurement method, including corrections for heart rate, age, and sex.

2019年6月10日 · To this end, a prolonged QTc, defined as a QTc value >450 ms in males and >460 ms in females measured preferably in lead II or V 5 on a standard 12-lead ECG, predisposes to functional reentry, torsades de pointes, and sudden cardiac death (SCD), and represents a widely accepted, easily measured, and quantifiable risk factor for adverse outcomes ...

This review discusses the components of accurate QTc measurement and diagnosis, re-examines what is known about factors affecting QT interval measurement, and clarifies current recommendations regarding diagnosis of so-called “borderline” QT interval prolongation.

Arsenic trioxide, used to treat acute promyelocytic leukaemia, has been associated with QTc prolongation in approximately 20% of patients, although the overall risk of TDP remains low. 52 Tyrosine kinase inhibitors are used to treat a variety of malignancies, and several have been linked with QTc prolongation and TDP. The drugs with reports of ...

This online evidence based resource will help guide you how to measure the QT interval and calculate the QTc value with an easy to use calculator which takes into account the patients underlying rhythm, gender and age.

The Corrected QT Interval (QTc) adjusts the QT interval correctly for heart rate extremes.

A maximum QTc threshold of 520 ms and median QTc threshold of 490 ms were determined to be strong predictors for BCEs. A landmark analysis controlling for age, sex, genotype, and symptomatic status demonstrated models utilizing both the median QTc and maximum QTc demonstrated the highest discriminatory value (c-statistic = 0.93-0.95).