Significance of reciprocal ST segment depression in ST elevation myocardial infarction

Background

The significance of reciprocal ST segment depression during acute myocardial infarction has been an area of debate, whether it is a sign of multivessel disease, ischemia at a distance or merely a benign electrical phenomenon.

Objective

To study the relation between the presence of reciprocal ST segment depression in ST elevation myocardial infarction, extent of coronary artery disease & left ventricular systolic function.

Patients and methods

A prospective, controlled study involving 200 ST elevation myocardial infarction patients (100 inferior, 100 anterior), each group was sub-grouped into 2 subgroups according to the presence of reciprocal ST segment depression or absence: in anterior STEMI group we had subgroup A1 with RSTD (41 patients) and subgroup A2 without RSTD (59 patients) while in inferior STEMI group each subgroup (B1 and B2) consisted of 50 patients. Echocardiography & coronary angiography were done for all patients.

Results

Patients with reciprocal ST segment depression showed a significant lower mean Left ventricular ejection fraction compared to those without (37 + 3% vs 53 + 5% P < 0.001, anterior ST elevation myocardial infarction subgroups) & (47 + 4% vs 60 + 3% P < 0.001, inferior ST elevation myocardial infarction subgroups). Higher incidence of multivessel disease was found in subgroups with reciprocal ST segment depression (80.5% vs 49.2%, P < 0.001 in anterior ST elevation myocardial infarction) & (60% vs 20%, P < 0.001 in inferior ST elevation myocardial infarction). The mean modified gensini score was higher in subgroups with reciprocal ST segment depression (64.2 + 12.6 vs 30.2 + 6.6, P < 0.001 in anterior infarction group) & (36.2 + 10.6 vs 20.4 + 4.2, p < 0.001 in inferior infarction group).

Conclusion

Reciprocal ST segment depression in acute myocardial infarction was associated with significant LV systolic dysfunction & greater extent of coronary artery disease.