Interactions Between Reciprocal ST-Segment Downsloping During ST-Elevated Myocardial Infarction and Global Cardiac Perfusion and Functional Abnormalities

Relation of collateral circulation with reciprocal changes in patients with acute ST-elevation myocardial infarction

OBJECTIVE

Acute STEMI is often accompanied by reciprocal ST-segment depression (RC) occurring in opposite leads, whose significance has been debated for decades. The possible role of collateral circulation in promoting RC in acute STEMI has not been identified. So our aim to find the relationship between collateral circulation and RC in STEMI patients treated with primary percutaneous intervention (PPCI).

METHODS

The study included 112 pts. with acute STEMI underwent PPCI. The patients divided in to 2 groups: Group (A):66 pts. with RC, Group (B):46 pts without RC. All patients subjected to history taking, ECG [localization of infarction & RC], CKMB level, transthoracic echo [LVEF%], coronary angiography &PPCI to culprit artery and assess number of diseased vessels, site of occlusion, collaterals, TIMI flow pre and post PCI.

RESULTS

Patients in group A with RC had shorter time to door, P < 0.001; more frequent inferior infarctions, P < 0.001; had higher CKMB level, P < 0.001; higher LVEDD, P < 0.001; LVESD, P < 0.001and lower LVEF, P = 0.004; had multi vessel diseases P = 0.02, increase incidence of RCA as a culprit artery <0.001 compared to patients with no RC. Patients with RC had significantly higher incidence of proximal LAD occlusion, distal RCA and distal LCX compared to patients without RC. The percentage of change was 61.2 ± 12.35% for ST elevation and 50.5 ± 10.87% for reciprocal ST depression post PCI with significance difference between them, t = 3.035P = 0.0023.There was no significant correlation between collateral circulation and RC. We found four significant independent predictors of RC. They were inferior infarction (P = 0.024), RCA as a culprit vessel, (P = 0.034), low EF, (P = 0.007) and multi-vessel disease, (P = 0.022).

CONCLUSION

There is no correlation between concomitant RC and presence of collateral vessels in acute STEMI patients. So the pathogenesis of reciprocal ST-segment changes result from an interplay of ischemia at distance due to multi-vessel CAD and benign mirror electrical changes not caused by collateral circulation diverting blood to ischemic area from non-diseased artery.

ST-segment depression in left precordial leads in electrocardiogram of patients with acute inferior myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND

The early identification of patients with acute inferior ST-segment elevation myocardial infarction (STEMI) with high risk features is particularly important. Acute inferior STEMI may be associated with ST-segment depression in the left precordial leads (V4-V6). This study assessed prognostic value of ST-segment depression in these left precordial leads during the admission of patients with acute inferior STEMI treated with primary percutaneous coronary intervention.

METHODS

This retrospective study enrolled 1,374 patients with acute inferior STEMI who underwent primary percutaneous coronary angioplasty between March 2011 and June 2014. The patients were divided into two groups: one group (n = 687) with left precordial ST-segment depression and the other (n = 687) without such ST-segment changes.

RESULTS

The patients with left precordial ST-segment depression were older and had higher incidence of hypertension, diabetes mellitus, and higher levels of troponin. In-hospital mortality was higher in patients with left precordial ST-segment depression. Advanced coronary artery disease was more observed in these patients.

CONCLUSION

In patients with acute inferior STEMI treated with primary coronary intervention, left precordial ST-segment depression during admission of ECG is associated with more advanced coronary artery disease, and worse in-hospital clinical outcomes.