A novel method for the detection of transient myocardial ischaemia using body suface electrocardiac mapping.

Background: The limitations of the 12-lead ECG in the detection of myocardial ischaemia are well known. This study sought to test the hypothesis that a Body Surface Mapping (BSM) system can detect and localise the transient regional ischaemia induced by elective percutaneous coronary intervention (PCI) in patients with stable angina. Methods and Results: 25 patients undergoing elective single vessel PCI were studied: 11 with RCA lesions, 9 with LAD lesions and 5 with circumflex lesions. Patients had BSM readings every 30 s following the inflation of a dilating balloon in the target vessel for 1 min. BSMs were analysed for ST segment change at 60 ms after the J point (ST60). Peak ST changes were analysed and colour map reconstruction made. Characteristic ST segment changes in each arterial domain were observed following inflation of the balloon. Maximal change occurred in a standard V lead on only 2/46 occasions. Statistically significant rapid rise and fall of ST 60 readings were observed indicating the onset recovery and location of the transient ischaemia. A novel method for the presentation of colour map reconstruction that removes baseline noise has been developed. Conclusions: These data confirm the hypothesis that this BSM system can detect and display transient myocardial ischaemia. BSM may represent a novel clinical tool for the assessment of clinical ischaemia.