The reappraisal of ST segment elevation as an index of infarct size in patients with acute anterior myocardial infarction.

The clinical meaning or precordial ST segment mapping for assessment of infarct size was studied in 12 patients with acute anterior myocardial infarction. sigma ST39 (the sum of ST segment elevations in 39 precordial leads), sigma STV1--6 (the sum of ST segment elevations in the standard chest leads) and STMAX (the maximum of ST segment elevation in 39 precordial leads) were obtained serially after the onset from precordial electrocardiographic mapping records. The infarct size and the time (Tf) when the evolution of myocardial infarction finished were calculated by the total creatine phosphokinase released (sigma CPK) and serial changes in CPK releasing rate, respectively. sigma STV1--6 at Tf, as closely as sigma ST39 (r = 0.82, p less than 0.01), correlated with sigma CPK (r = 0.79, p less than 0.01). Even STMAX at the time of Tf significantly correlated with sigma CPK (r = 0.60, p less than 0.05), although the correlation coefficient was not so well as the former two. These results showed that sigma STV1--6 reflected infarct size as satisfactorily as sigma ST39 and could be useful for measuring infarct size.