Electrocardiographic Identification Of The Culprit Coronary Artery In Inferior Wall Myocardial Infarction

ObjectiveTo predict the infarction of related artery (IRA) and the site of occlusion byanalyzing the diversify of electrocardiographic ST segment and coronaryangiography findings in acute inferior myocardial infarction.MethodsEighty-one patients with acute inferior myocardial infarction were dividedinto two groups by coronary angiography: right coronary artery (RCA)occlusion group (65patients) and left circumflex coronary artery (LCX)occlusion group (16patients). RCA occlusion group included proximal,middle and distal components occlusion, and LCX occlusion group includedproximal and distal components occlusio. The cases of STⅢelevation> STⅡ,STaVLdepression> STⅠ, STV1depression, STV7-V9and STV3R-V5Relevationwere recorded and compared.ResultsThe percentage of STⅢelevation> STⅡ, STaVLdepression> STⅠ, STV1nodepression, STV7-V9no elevation and STV3R-V5Relevation was significantlyhigher in RCA occlusion group than those in LCX occlusion group （P<0.01）. The percentage of STⅢelevation≤STⅡelevation, STaVLdepression≤STⅠ, STV1depression, STV7-V9elevation, STV3R-V5Rno elevation was significantly higher inLCX occlusion group than those in RCA occlusion group （P<0.01）. In RCAocclusion group: the sensitivity of STⅢelevation> STⅡ, STaVLdepression> STⅠ,STV1no depression was90.8%,83.1%and81.5%; the specificity of STⅢelevation> STⅡ, STaVLdepression> STⅠwas75.0%and75.0%; the sensitivityof STV3R-V5Relevation was56.9%, but its specificity was93.8%. In LCXocclusion group: the sensitivity of STⅢelevation≤STⅡelevation, STaVLdepression≤STⅠwas75.0%and75.0%, and their specificity was90.8%and83.1%; the specificity of STV1depression, STV7-V9elevation was81.5%and73.8%; the sensitivity of STV3R-V5Rno elevation was93.8%, and its specificitywas56.9%. In RCA occlusion group, the percentage of STV3R-V5Relevation washigher in proximal components occlusion than that in distal componentsocclusion [86.4%（19/22）vs.25.0%（3/12），P<0.01].ConclusionsThe IRA can be initially judged by analysis of the characteristics in the STsegment in Ⅰ， Ⅱ， Ⅲ， aVL， V1，V7-V9，V3R-V5Rlead in acute inferiormyocardial infarction. And the ST segment elevation in V3R-V5Ris meaningfulin the judgment of proximal and distal components occlusion in RCA.