Q-wave abnormalities in chronic obstructive pulmonary disease and myocardial infarction

ECGs taken from patients with chronic obstructive pulmonary disease (COPD) frequently mimic myocardial infarction (MI), and may, therefore, cause diagnostic difficulties for the physician. In many previous studies, criteria to differentiate electrocardiographically between COPD and MI were either untested in large numbers of cases or too complicated for routine use. This study was undertaken to find simple new criteria, using scalar measurements which are easily obtainable in clinical practice. To assure the stability and repeatability of our results, the accuracy of these criteria was tested in a large series of cases. Three-hundred and ninety-six (396) cases of COPD and eight-hundred and seventy-eight (878) cases of MI comprised the material for this study. The COPD cases were grouped into two: a training set of 266 cases and a test set of 130 cases. There were three MI subgroups: AMI-344 cases, PDMI-449 cases, and LMI-85 cases. By applying the proposed ECG criteria specifically on the "COPD--MI mimics," we were able to reduce the number of potentially mis-diagnosed COPD cases (based purely on Q-wave abnormality) from 158 cases (40% of all COPD cases) to 71 cases (18%).