Fast, accurate and easy-to-teach QT interval assessment: The triplicate concatenation method

Valentin Saqué; Martino Vaglio; Christian Funck-Brentano; Maya Kilani; Olivier Bourron; Agnès Hartemann; Fabio Badilini; Joe-Elie Salem

doi:10.1016/j.acvd.2016.12.011

Fast, accurate and easy-to-teach QT interval assessment: The triplicate concatenation method

Arch Cardiovasc Dis. 2017 Aug-Sep;110(8-9):475-481. doi: 10.1016/j.acvd.2016.12.011. Epub 2017 May 11.

Authors

Valentin Saqué¹, Martino Vaglio², Christian Funck-Brentano¹, Maya Kilani¹, Olivier Bourron³, Agnès Hartemann³, Fabio Badilini², Joe-Elie Salem⁴

Affiliations

¹ INSERM, CIC-1421 and UMR ICAN 1166, France; Department of Pharmacology and CIC-1421, Pitié-Salpêtrière Hospital, AP-HP, France; Faculty of Medicine, Sorbonne University, UPMC University of Paris 06, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.
² AMPS-LLC, New York, NY, USA.
³ Diabetology Department, Pitié-Salpêtrière Hospital, AP-HP, France; Faculty of Medicine, Sorbonne University, UPMC University of Paris 06, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France.
⁴ INSERM, CIC-1421 and UMR ICAN 1166, France; Department of Pharmacology and CIC-1421, Pitié-Salpêtrière Hospital, AP-HP, France; Faculty of Medicine, Sorbonne University, UPMC University of Paris 06, France; Institute of Cardiometabolism and Nutrition (ICAN), Paris, France. Electronic address: joe-elie.salem@aphp.fr.

PMID: 28501559
DOI: 10.1016/j.acvd.2016.12.011

Abstract

Background: The gold standard method for assessing the QTcF (QT corrected for heart rate by Fridericia's cube root formula) interval is the "QTcF semiautomated triplicate averaging method" (TAM), which consists of measuring three QTcF values semiautomatically, for each 10-second sequence of a triplicate electrocardiogram set, and averaging them to get a global and unique QTcF value. Thus, TAM is time consuming. We have developed a new method, namely the "QTcF semiautomated triplicate concatenation method" (TCM), which consists of concatenating the three 10-second sequences of the triplicate electrocardiogram set as if they were a single 30-second electrocardiogram, and measuring QTcF only once for the triplicate electrocardiogram set.

Aim: To compare the TCM method with the TAM method.

Methods: Fifty triplicate electrocardiograms were read twice by an expert and a student using both methods (TAM and TCM). We plotted Bland-Altman plots to assess agreement between the two methods, and to compare the student and expert results. The time needed to read a set of 20 consecutive triplicate electrocardiograms was measured.

Results: Limits of agreement between TAM and TCM ranged from -8.25 to 6.75ms with the expert reader. TCM was twice as fast as TAM (17.38 versus 34.28min for 20 consecutive triplicate electrocardiograms). Bland-Altman plots comparing student and expert results showed limits of agreement ranging from -4.34 to 11.75ms for TAM, and -1.2 to 8.0ms for TCM.

Conclusions: TAM and TCM show good agreement for QT measurement. TCM is less time consuming than TAM. After a learning session, an inexperienced reader can measure the QT interval accurately with both methods.

Keywords: Education; Mesure de l’intervalle QT; Mesure semi-automatique; Method validation; Pédagogie; QT interval measurement; Semiautomated measurement; Validation de méthode.