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Updated: Mar 23, 2026
Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Electrical Dyssynchrony on Noninvasive Electrocardiographic Mapping correlates with SAI QRST on surface ECG
Larisa G Tereshchenko1, Elyar Ghafoori2, Muammar M Kabir2
1Oregon Health and Science University, Knight Cardiovascular Institute, Portland, OR, USA; Johns Hopkins University School of Medicine, Cardiovascular Division, Baltimore, MD, USA.
Aim:
The goal of this study was to compare associations between clinical and ECG predictors of cardiac resynchronization therapy (CRT) response with electrical dyssynchrony.
Methods:
Body-surface potentials were recorded using a 120-lead system in 4 patients (age 62 ± 12 y, left ventricular ejection fraction (LVEF) 29 ± 5 %; QRS duration 154 ± 19 ms) with post-myocardial infarction scar and left bundle branch block before CRT implantation. A patient-specific heart-torso model derived from MRI with 291 heart-surface nodes was developed. Electrical dyssynchrony index (EDI) was computed as the standard deviation of activation times on the epicardium while uncoupling index (UI) was measured as the difference between the activation times.
Results:
QRS duration correlated with mean activation time (r = 0.977; P = 0.023), but did not correlate with EDI or UI. LVEF inversely correlated with activation time at the lowest 20th percentile (r = -0.960; P = 0.040). Sum absolute QRST integral (SAI QRST), measured on orthogonal XYZ ECG, correlated with EDI (r = 0.955; P = 0.045), and characterized late-activated area of the left ventricle.
Conclusion:
SAI QRST is a measure of electrical dyssynchrony on ECG.
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