Significance of ST Segment, R Wave, Q Wave and QRS Score for Assessing Myocardial Perfusion in Acute Myocardial Infarction

Ahn, Jeong Cheon; Kim, Soo Mi; Hwang, Kyo Seung; Lee, Eun Mi; Song, Woo Hyuk; Park, Chang Gyu; Kim, Young Hoonm; Seo, Hong Seog; Shim, Wan Joo; Oh, Dong Joo; Ro, Young Moo

Abstract

BACKGROUND AND OBJECTIVES
The restoration of infarct-related coronary artery (IRA) patency in acute myocardial infarction (AMI) linked to a significant improvement in survival. Because of microvascular and cellular injury, patent IRA does not always represent successful reperfusion. With progress of myocardial ischemia, standard 12 lead ECG shows evolutional changes of ST-segment, R wave and Q wave. But their relations to myocardial perfusion were uncertain.
METHODS
Total 41 patients of the first anterior wall AMI were enrolled and serial ECGs were taken to measure sum of ST-segment elevation (sigma ST), sum of Q wave (sigma Q), sum of R wave (sigma R), and QRS score (QRSs) proposed by Selvester in each patients before thrombolytic therapy (i), after coronary angiography at 90 minutes of thrombolytic therapy (a), and before discharge (d). Myocardial contrast echocardiography was performed within 10 days of AMI to estimate opacification score (OS) and opacification index (OI) in segments of LAD territory. We investigate the relation between evolution of ECG changes and perfusion status of infarcted myocardium.
RESULTS
1) There was no relation between OI and sigma ST, but sigma R and QRSs showed significant relation with OI before discharge (r=0.59, - 0.33, p<0.05, respectively), post thrombolytic therapy (r=0.51, - 0.61, p<0.05), and baseline ECG (r=0.53, - 0.51, p<0.05). 2) The number of segments with OS (0.5) showed no singificant relation to the degree of sigma ST and sigma Q, but number of segments with OS (0) showed singinficant relation to that of sigma R and QRSs (r of sigma Ri, sigma Ra, sigma Rd vs number of segments with OS (0)= - 0.59, - 0.66, - 0.43, p<0.05, QRSi, QRSa, QRSd vs number of segments with OS (0)=0.58, 0.58, 0.57, p<0.05).
CONCLUSION
These findings suggest that the ECG changes of R wave and QRS scores could be useful markers of perfusion state in thrombolytic era.