ABSTRACT
Introduction: Various electrocardiogram (ECG) patterns can determine the site of occlusion in culprit coronary artery in ST-elevation myocardial infarction (STEMI) and the size of the myocardium that is jeopardized. Objectives: The aim of this study was to assess diagnostic accuracy of the ECG localization of culprit vessel occlusion site as compared to coronary angiographic findings. Material and methods: ECG criteria for localization of culprit vessel occlusion site were specified and patients with STEMI (n = 21) were divided into three groups: Groups I, II and III, according to the localization of culprit vessel occlusion site in left anterior descending (LAD), right coronary artery (RCA) and left circumflex (LCx) coronary arteries, respectively. Group I was further divided into four subgroups: Ia, Ib, Ic and Ib+c according to whether occlusion in LAD was proximal to both first septal (S1) and first diagonal (D1) branches, distal to S1 but proximal to D1 branches, distal to both S1 and D1 branches or distal to S1 branch, respectively. Group II was further divided into two subgroups: IIa and IIb according to whether occlusion in RCA was proximal or distal to RV branch, respectively. The results of coronary angiograms were compared with those predicted by ECG. Results: The positive predictive accuracy (PPA) and negative predictive accuracy (NPA) of ECG criteria for LAD, RCA and LCx coronary arteries were 90.91% and 100%, 90% and 100%, and undetermined and 90.48%, respectively. Among subgroups, the sensitivity of ECG criteria was maximum for groups Ib+c and IIb (100%) followed by Group IIa (71.43%), Group Ic (50%), Group Ia (42.86%) and least for Group Ib (0%). The specificity was maximum for Groups Ia and IIa (92.86%) followed by Group Ib (90%), Group IIb (89.47%), Group Ic (78.95%) and Group Ib+c (77.78%) in that order. The PPA and NPA for Groups Ia, Ib, Ic, Ib+c, IIa and IIb were 75% and 76.47%, 0% and 94.74%, 20% and 93.75%, 42.86% and 100%, 83.33% and 86.67% and 50% and 100%, respectively. Conclusion: The present study demonstrates that ECG is an easily and widely available inexpensive tool to localize site of occlusion in culprit vessel in acute STEMI.