Newly Developed Signal-Averaged Vector-Projected 187-Channel Electrocardiogram Can Evaluate the Spatial Distribution of Repolarization Heterogeneity

Abstract

The purpose of this study was to verify the spatial distribution of myocardial repolarization heterogeneity using a newly developed 187-channel signal-averaged vector-projected ECG (187-ch SAVP-ECG).
We constructed corrected recovery time (RTc) and Tpeak-end (corrected Tp-e) dispersion maps using a 187-ch SAVP-ECG based on vector-projection theory using a Mason-Likar lead system. We compared the spatial distribution and quantitative values of dispersion maps by 187-ch SAVP-ECG with those by 64-ch magnetocardiography (MCG) in 27 normal controls (control) and 16 patients (12 myocardial infarction (MI), and 4 dilated cardiomyopathy (DCM)).
The wave pattern of the 187-ch SAVP-ECG in the representative cases was similar to those in 64-ch MCG. Spatial distribution increased RTc and corrected Tp-e dispersion maps defined by 187-ch SAVP-ECG were in agreement with those by 64-ch MCG. The value of RTc dispersion in MI was higher than that in control (41 ± 21 ms in MI versus 30 ± 12 ms in control, P < 0.05). The value of corrected Tp-e dispersion in DCM was higher than that in control (58 ± 12 ms in DCM versus 30 ± 13 ms in control, P < 0.001). There was a good correlation between RTc and corrected Tp-e dispersion values determined by 187-ch SAVP-ECG and 64-ch MCG modalities (y = 0.46x + 18, r = 0.62, P = 0.02 for RTc dispersion; y = 0.52x + 15, r = 0.63, P = 0.01 for corrected Tp-e dispersion).
RTc and corrected Tp-e dispersion maps by 187-ch SAVP-ECG based on vector-projection theory can evaluate the spatial distribution of myocardial repolarization heterogeneity.