Criteria have been developed and published for the detection of ST segment elevation myocardial infarction (STEMI) in the 12-lead electrocardiogram (ECG). In this study we report on an algorithm for the detection of ST segment elevation in body surface potential maps (BSPM). The algorithm seeks ST segment elevation, exceeding predefined thresholds, in two contiguous/adjacent leads. Thresholds are based upon the extension of existing 12-lead ECG criteria. The algorithm was applied to 45 subjects who had 120-lead BSPMs recorded during percutaneous transluminal coronary angioplasty (PTCA). The algorithm was capable of distinguishing between baseline ECGs and peak balloon inflation ECGs with a sensitivity of 84.4% and specificity of 86.7%. Standard STEMI criteria, applied to 12-lead ECGs extracted from the same BSPMs, resulted in a sensitivity of 53.3% and a specificity of 100 %. The BSPM algorithm has the potential to increase sensitivity but specificity is reduced.