Cardiology
ECG: A Simple Noninvasive Tool to Localize Culprit Vessel Occlusion Site in Acute STEMI Biplab Ghosh*, Manoj Indurkar**, Mahendra Kumar Jainâ€
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.
Keywords: Culprit vessels, STEMI, ECG, coronary angiography
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he standard 12 lead electrocardiogram (ECG) has long been a reliable clinical tool for diagnosis of acute myocardial infarction (AMI). Specific ECG patterns for the site of occlusion in culprit coronary artery has been well-recognized.1 Larger the area at risk, more aggressive should be the attempt to restore or improve perfusion of that area. Objectives The aim of this study was to amalgamate various ECG criteria for localization of culprit vessel occlusion site *Senior Resident Dept. of Nephrology, Institute of Medical Sciences Banaras Hindu University, Varanasi, Uttar Pradesh **Associate Professor †Professor Dept. of Medicine, Shyam Shah Medical College Rewa, Madhya Pradesh Address for correspondence Dr Biplab Ghosh Senior resident Dept. of Nephrology, Institute of Medical Sciences Banaras Hindu University, Varanasi - 221 005, Uttar Pradesh E-mail: dr.biplabghosh@gmail.com
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Indian Journal of Clinical Practice, Vol. 23, No. 10 March 2013
and to assess its diagnostic accuracy as compared to follow-up coronary angiographic findings. Material and Methods The present study was carried out on patients admitted with AMI after application of the following exclusion criteria: Patients with history of previous myocardial infarction and previous coronary artery bypass graft (CABG) surgery; ECG evidence of left bundle branch block (LBBB), pre-excitation and paced rhythm. Written informed consent was obtained from each patient. AMI was diagnosed as per standard criteria.1 A detailed history and physical examination was carried out. ECG was recorded on admission and then 90 minutes and three hours after completion of thrombolysis, and if thrombolysis was not done, at four hours and 24 hours after admission. Besides these ECG was also recorded whenever symptoms and clinical situations demanded so. In inferior wall, AMI right sided leads and posterior leads were also recorded. Patients were referred to other hospitals for coronary angiography and the results were noted on subsequent follow-up. A lesion