Characteristics and mechanism of reciprocal ST-segment depression in acute ST segment elevation myocardial infarction

Background At present, the mechanism of reciprocal ST-segment depression(RSTD) is still not clear. Methods The electrocardiogram and angiography of 85 STEMI patients were retrospectively analyzed to summarize the characteristics of ST segment changes and explore the mechanism of RSTD. Results A total of 85 patients were included, of which 75 were patients with RSTD (10 patients with anterior myocardial infarction had no RSTD), all 45 patients with inferior myocardial infarction had limb leads RSTD, and 37 of them had anterior lead ST segment depression.Thirty patients with anterior myocardial infarction were accompanied by mild ST segment changes in the limb leads. According to the characteristics of RSTD, it is speculated that the mechanism of RSTD is that the action potential of infarct area decreased, which could not offset the action potential in non-infarct area. Conclusion the mechanism of RSTD in acute myocardial infarction maybe that the negative electrode action potential of the lead was weakened or disappeared, and the positive electrode action potential could not be completely offset, resulting in ST segment depression.