Correction of the QRS duration for heart rate

Mason, Jay W.; Strauss, David G.; Vaglio, Martino; Badilini, Fabio

doi:10.1016/j.jelectrocard.2019.02.005

Cited by 10 publications

(13 citation statements)

References 9 publications

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“…Blood samples were taken at −1 (predose), 2,6,23,26,30,47,49,50,51,52,53,54,56,58,60,72,96, and 120 hours after the first dose. All participants received the drugs at 08:00 am daily for 3 days (days 0, 1, and 2) and the electrocardiograph (ECG) measurements (described below) were conducted in triplicate just before blood sampling.…”

Section: Methodsmentioning

confidence: 99%

“…A linear correction factor was introduced to the QRS-RR relationship as a population-based and subject-specific correction. 23,24 The JT-RR relationship was evaluated in the same way as the rate correction of QT intervals (i.e., estimating a correction factor ). In addition, we evaluated a simpler way of correcting the JT interval by calculating the differences between corrected QT and QRS intervals, according to Eq.…”

Section: Electrocardiographic Analysismentioning

confidence: 99%

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Pharmacometric and Electrocardiographic Evaluation of Chloroquine and Azithromycin in Healthy Volunteers

Chotsiri

Tärning

Hoglund

et al. 2022

Clin Pharma and Therapeutics

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Chloroquine and azithromycin were developed in combination for the preventive treatment of malaria in pregnancy, and more recently were proposed as coronavirus disease 2019 (COVID-19) treatment options. Billions of doses of chloroquine have been administered worldwide over the past 70 years but concerns regarding cardiotoxicity, notably the risk of torsades de pointes (TdP), remain. This investigation aimed to characterize the pharmacokinetics and electrocardiographic effects of chloroquine and azithromycin observed in a large previously conducted healthy volunteer study. Healthy adult volunteers (n = 119) were randomized into 5 arms: placebo, chloroquine alone (600 mg base), or chloroquine with either 500 mg, 1,000 mg, or 1,500 mg of azithromycin all given daily for 3 days. Chloroquine and azithromycin levels, measured using liquid-chromatography tandem mass spectrometry, and electrocardiograph intervals were recorded at frequent intervals. Time-matched changes in the PR, QRS, and heart rate-corrected JT, and QT intervals were calculated and the relationship with plasma concentrations was evaluated using linear and nonlinear mixed-effects modeling. Chloroquine and azithromycin pharmacokinetics were described satisfactorily by two-and three-compartment distribution models, respectively. No drug-drug interaction between chloroquine and azithromycin was observed. Chloroquine resulted in concentration-dependent prolongation of the PR, QRS, JTc and QTc intervals with a minimal additional effect of azithromycin. QRS widening contributed ~ 28% of the observed QT prolongation. Chloroquine causes significant concentration-dependent delays in both ventricular depolarization and repolarization. Co-administration of azithromycin did not significantly increase these effects. The arrhythmogenic risk of TdP associated with chloroquine may have been substantially overestimated in studies which did not separate electrocardiograph QRS and JT prolongation.

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Section: Methodsmentioning

confidence: 99%

Section: Electrocardiographic Analysismentioning

confidence: 99%

Pharmacometric and Electrocardiographic Evaluation of Chloroquine and Azithromycin in Healthy Volunteers

Chotsiri

Tärning

Hoglund

et al. 2022

Clin Pharma and Therapeutics

View full text Add to dashboard Cite

show abstract

“…Abrupt changes in the heart rate may lead to QRS widening. However, some authors demonstrated that the duration of the QRS complex is frequently shortened by spontaneous increases in heart rate [30,31] or burst pacing in the AAI mode [32]. The latest model is closer to our experimental protocol, but we fail to capture that dynamic behavior as the QRS width remained constant along our frequency range.…”

Section: Discussionmentioning

confidence: 79%

The QT Interval Dynamic in a Human Experimental Model of Controlled Heart Rate and QRS Widening

Colunga

Padrón

Iglesias

et al. 2019

JCM

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Background: there is increasing interest for computing corrected QT intervals in patients with prolonged depolarization. We aimed to analyze the effect of prolonged QRS in the QT and in the diagnostic accuracy of frequency-correction. Methods and Results: in 28 patients admitted for self-expanding aortic valve implantation, sequential pacing was performed in the AAI mode in two different phases: before and immediately after the release of the prosthesis. We evaluated the accuracy of the Bazett, Fridericia, Framingham and Hodges formulas with the reference of the QT at 60 bpm (QTc/deviation). The widening of the QRS was the main contributor to the QT prolongation (Pearson 0.79; CI95%: 0.75–0.84). Prolongation in other intervals (ST segment and T-wave) significantly contribute in the higher frequency range (p < 0.05). The Bazett’s formula displayed the highest QTc/deviation, while Framingham and Hodges retrieved the lowest QTc/deviation and the best fit (p < 0.001). In addition, the Bazett’s formula displayed the highest correlation between variations in the QTc/deviation and the widening of the QRS (Pearson coefficient −0.54; p < 0.001) in comparison with the Fridericia, Framingham and Hodges formulas (−0.51, −0.37 and −0.38 respectively; p < 0.001). There was also a linear effect of the heart rate in the QTc/deviation obtained with the Bazett’s formula (p = 0.015), not observed for other formulas. Conclusions: The prolonged depolarization of the ventricles introduces direct and linear prolongation in the QT interval, but also a non-linear distortion in cardiac repolarization that contributes for QT prolongation at the higher frequency range. The Bazett’s formula displays significantly higher sensitivity to prolongation of ECG intervals.

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“…The average of two independent measurements was taken for statistical analysis. Considering the importance of QRS duration in risk stratification and its potential dependence on momentary HR, we decided to correct the QRS for HR according to a formula created by previous authors [ 6 ]: QRSc = QRS + 0.0125 × (1000 − RR), where QRSc—corrected QRS duration; QRS—measured QRS duration; and RR—mean RR interval.…”

Section: Methodsmentioning

confidence: 99%

What Is the Importance of Electrocardiography in the Routine Screening of Patients with Repaired Tetralogy of Fallot?

Lubocka

Sabiniewicz

2021

JCM

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Background: In patients following complete repair of the tetralogy of Fallot, the duration of the QRS complex is associated with the size and mechanical function of the right ventricle, which are contemporarily assessed by cardiac magnetic resonance (CMR). Methods: 38 patients aged 18.0–54.9 years (median age 24.9 years) who had undergone complete repair of the tetralogy of Fallot were examined using CMR and concomitant 24 h ambulatory electrocardiography monitoring. We used statistical analysis to investigate the correlations between electrocardiographic parameters (heart rate, HR; PQ interval, PQ; QRS duration, QRS; and corrected QT interval, QTc) and CMR results (right ventricular ejection fraction, RVEF; right ventricular end-diastolic volume index, RVEDVI; and right ventricular end-systolic volume index, RVESVI) for patients after early and late repair. Results: The ECG-based parameters were not correlated with time since repair. There were significant correlations between QRS duration and RVEF (r = −0.61), RVEDVI (r = 0.56), and RVESVI (r = 0.54) for early operated patients but not for late-operated patients. No other substantial correlations were reported. Conclusion: Despite its role in screening for arrhythmias, electrocardiography has a limited role as a predictor of morphology and function of the right ventricle in patients after repair of the tetralogy of Fallot.

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Correction of the QRS duration for heart rate

Cited by 10 publications

References 9 publications

Pharmacometric and Electrocardiographic Evaluation of Chloroquine and Azithromycin in Healthy Volunteers

Pharmacometric and Electrocardiographic Evaluation of Chloroquine and Azithromycin in Healthy Volunteers

The QT Interval Dynamic in a Human Experimental Model of Controlled Heart Rate and QRS Widening

What Is the Importance of Electrocardiography in the Routine Screening of Patients with Repaired Tetralogy of Fallot?

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