Development of a signal-averaged vector-projected 187-channel high-resolution electrocardiogram for the evaluation of the spatial location of high-frequency potentials and abnormal ventricular repolarization.

Noninvasive risk stratification is important for screening for lethal arrhythmia. We developed a 187-channel signal-averaged vector-projected high-resolution electrocardiograph (187-ch SAVP-ECG) for detecting abnormalities in the spatial location of ventricular high-frequency late potentials (HFLPs) and ventricular repolarization. The subjects consisted of 30 normal controls (CONTROL) and 13 patients with HFLPs (6 with myocardial infarction [MI], 6 with cardiomyopathy, and 1 with Brugada syndrome). The modified X, Y, Z-lead ECG and the synthesized signals from vector-projected 187-channel ECGs were amplified and passed through a digital filter. We calculated the integration of the HFLPs area between QRS(end) and 30 ms before QRS(end). The integrated HFLPs map was superimposed on the corrected recovery time (RTc) and Tpeak-end dispersion maps composed by 187-ch SAVP-ECG. All patients received an examination by 64-channel magnetocardiography (64-ch MCG) on the same day. The spatial distribution of HFLPs by the 187-ch SAVP-ECG map was in agreement with the location of increased RT dispersion in MI. The spatial distribution of HFLPs in DCM demonstrated a wide variety of patterns. Interestingly, the spatial distribution of HFLPs in cases with ARVC was located at around a right ventricular outflow region. The spatial distribution of HFLPs by 187-ch SAVP-ECG was in agreement with those determined by 64-ch MCG. The 187-ch SAVP-ECG might be useful for evaluating the spatial distribution of nonuniform conduction and ventricular repolarization heterogeneity.