Clinical value of different QRS-T angle expressions

Area of Science:

• Cardiology
• Medical Imaging
• Biomedical Engineering

Background:

• The spatial angle between QRS complex and T wave loop orientations is a known cardiac risk predictor.
• Current methods for calculating the QRS-T angle lack consensus, impacting clinical application.

Purpose of the Study:

• To compare the reproducibility and predictive power of three common QRS-T angle assessment methods.
• To identify the optimal method for clinical use and standardization.

Main Methods:

• Utilized electrocardiograms from 352 healthy subjects, 941 acute myocardial infarction (MI) survivors, and 605 implantable cardioverter defibrillator (ICD) recipients.
• Measured QRS-T angle using Maximum R to T (MRT), Area R to T (ART), and Total Cosine R to T (TCRT) methods.
• Compared reproducibility and 5-year mortality prediction in cardiac patient cohorts.

Main Results:

• MRT method showed significantly lower reproducibility compared to ART and TCRT.
• TCRT method demonstrated superior statistical power in predicting mortality among MI survivors and ICD recipients.
• TCRT identified sudden cardiac death risk in MI survivors (AUC 78%) and mortality in ICD recipients with prolonged QRS duration.

Conclusions:

• The TCRT method offers significant advantages for spatial QRS-T angle assessment.
• TCRT should be considered for future clinical studies and standardization of QRS-T angle measurement.
• TCRT provides a reliable tool for cardiac risk stratification.