ST segment mapping and infarct size.

1. Introduction changes were unknown at that time, but Holland and Brooks in several papers emphasised that ST segment Following the pioneering studies of Julian [1] and Lown changes are influenced by both spatial and non-spatial and coworkers [2], demonstrating that ventricular fibrilla-factors [8–10]. Important spatial factors included the tion is common in patients with acute ischaemia, with and position of the recording electrode with respect to the without infarction, and that it can be treated, coronary care ischaemic tissue boundaries and the size of the ischaemic units were installed in many medical centres, and attempts zone; non-spatial factors are the differences in transmem-were made to hospitalise patients with acute ischaemic brane voltage between ischaemic and non-ischaemic attacks as early as possible. As Professor Shillingford myocardium, which could be altered, for example, by