Clinical application of body surface Laplacian mapping in diagnosis of myocardial infarction

The feasibility of applying body surface Laplacian mapping to aid clinical diagnosis of myocardial infarction (MI) was tested. Potential ECGs were recorded from the anterolateral chest of a patient with prior MI as determined by clinical criteria. After pre-processing, the Laplacian ECGs were calculated using a finite difference estimation algorithm. Results of the 12-lead ECG, echocardiogram, and body surface potential maps (BSPM) were examined and compared to the early depolarization activities observed in the body surface Laplacian maps (BSLM). The BSLMs showed a localized initial negativity as early as 18 ms after the onset of the QRS complex. In contrast, healthy subjects showed an initial positivity at the same time point. The negativity in the BSLM of the patient appeared to overlie the site of MI as determined by 12-lead ECG and echocardiographic criteria. The negativity, a spatial equivalent of the ECG Q wave, was much more localized as compared to the corresponding potential maps, and may better reflect the extent of MI as compared to the BSPMs