Remodeling in myocardial infarction and body surface potential maps

This study deals with the capabilities of body surface integral and departure maps to evaluate the chronic stage of myocardial infarction based on dividing the left ventricle into 12 segments. The effects of ventricular remodeling on electrocardiographic potential distributions are considered. A 61-year-old male patient was examined five times by body surface potential mapping during a period of 9 months after acute myocardial infarction. Integral maps were calculated for 60 ms after QRS onset and compared with mean data from a control group using departure maps. Integral maps showed a continual reduction of negative potentials in the lower half of the torso with time. The negative area covered the lower torso in the departure maps during the whole study, but its form and value changed. According to the location of the departure area, the surface projection of the scar moved from a position corresponding to inferior segments to a position corresponding to posterior segments. Its size also decreased. Echocardiographic examinations showed progressive enlargement of both ventricles with time. Therefore, the authors postulate that the changing pattern of body surface potential maps was mainly influenced by ventricular remodeling after myocardial infarction.