"Mirror-lake" serial relationship of electrocardiographic and biochemical indices for the detection of reperfusion and the prediction of salvage in patients with acute myocardial infarction

Background: Serial observations of biochemical markers in the blood and bioelectric markers on the electrocardiogram (ECG) have been used to evaluate the effectiveness of reperfusion therapy in acute myocardial infarction (AMI). This study presents a combined method for clinical use, based on the "mirror-lake" tendency of the serial changes in these markers. Methods: Consecutive thrombolytic-treated patients with AMI (n = 43) had ST-segment monitoring (Mortara Eli 100) and frequent serum sampling of myoglobin (MG) concentration. Their acutely predicted and finally estimated AMI sizes and myocardial salvage extents were calculated from the 12-lead standard ECG. Patients having 2 positive reperfusion indices (ST resolution at least 50%, and an increase in MG at least 2.4 fold) at 2 hours after initiation of thrombolytic therapy were considered the "complete reperfusion" group, and patients with discordant or 2 negative reperfusion indices after 2 hours of thrombolytic therapy were considered the "limited reperfusion" group. Results: Patients with complete reperfusion (n = 22) versus patients with limited reperfusion (n = 21) had +12% versus -1% myocardial salvage (P < .0001). The serial changes in the ST segment mirrored the serial changes in the MG concentration, and the rates of increase in MG correlated with the rates of resolution of the ST-segment elevation. Conclusion: Myocardial salvage (measured by ECG indices) is greatest when an early increase in serum MG is "mirrored" by early resolution of ST-segment elevation.