Relation between ST and QRS vector changes and myoglobin release in acute myocardial infarction.

We analysed serum time activity curves for myoglobin (MG) and changes in the ST and QRS vectors for 18 consecutive patients with acute myocardial infarction admitted within 4 h of the onset of pain. The MG release was completed 16 +/- 7 (7 to 36) h after onset of symptoms, and the QRS vector changes were completed after 14 +/- 5 (4 to 23) h. the ST vector decline ceased after 11 +/- 5 h. The temporal correlation between completion of: a) ST vectors and MG release was r = 0.78 (P less than 0.001); b) QRS vectors and MG release was r = 0.85 (P less than 0.001). Stepwise release of MG and changes in ST and QRS vectors were often related. Seventeen additional ST-peaks were followed by further MG-release in 13 instances and for 10 additional changes of the QRS vector eight were associated with further MG-release. We conclude that VCG changes and MG-release show a close temporal relationship. Additional events are often simultaneously reflected by these independent markers of myocardial ischaemia and necrosis.