Adaptive time-frequency ECG analysis

Non-stationary analysis of ECG using the Choi-Williams (CW) distribution (H. Choi & W.J. Williams, 1989) is presented. An analysis was carried out on subjects with acute myocardial infarction (AMI) who had undergone thrombolysis, in V1 Holder recordings. Two groups of patients were looked at: successfully and unsuccessfully thrombolysed patients. The time-frequency map generated by the CW transform (a modification of the Wigner-Ville transform) was divided into nine areas relevant to ECG features. Characteristic parameters were extracted from each area, and linear discriminant analysis was applied to these parameters, leading to a prediction index. Applying the method to ECGs six hours after lysis, the successfully thrombolysed patients were shown to be distinct from the unsuccessfully thrombolysed ones.