Improved personal computer-based system supports qualitative and quantitative applications of 3-D body surface precordial maps

The authors describe experience with a MAPCARD system application, both in research and clinical environments, and its latest improvements which support qualitative and quantitative application of three-dimensional (3-D) body-surface precordial maps. The MAPCARD system consists of an external data-acquisition subsystem, connected by standard communication protocols to an IBM-compatible personal computer (PC). MAPAS, the application software, runs over the MS-DOS operating system. Simultaneous acquisition of up to 36 channels can be performed at 250-Hz, 500-Hz, or 1-KHz sampling rates with four options of amplifier gain. A study of ST60 segment changes with stress, using the 3D approach to qualify and quantify induced myocardial ischemic changes, is also discussed. It is found that the comparison of 3-D ST segment maps in rest and stress is a reliable and fast method for diagnosing the presence and location of coronary ischemia. Volume quantification improves the accuracy of the method. For the time being, however, it cannot be used to grade myocardial ischemia in an absolute way