Improving the Diagnosis of Culprit Left Circumflex Occlusion With Acute Myocardial Infarction in Patients With a Nondiagnostic 12‐Lead ECG at Presentation: A Retrospective Cohort Study

Background Left circumflex culprit is often missed by the standard 12‐lead ECG. Extended lead systems (body surface potential map [BSPM]) should improve the diagnosis of culprit left circumflex stenosis with myocardial infarction. Methods and Results Retrospective analysis of a hospital research registry (August 2000–August 2010) comprising consecutive patients with (1) ischemic‐type chest pain at rest; (2) 12‐lead ECG and 80‐lead BSPM at first medical contact; and (3) cardiac troponin‐T 12 hours after symptom onset and/or creatine kinase MB fraction, were undertaken. Enrolled in the cohort were patients with culprit left circumflex stenosis (thrombolysis in myocardial infarction flow grade 0/1) at angiography. Acute myocardial infarction AMI was defined as cardiac troponin‐T ≥0.1 μg/L and/or creatine kinase MB fraction >2 upper limits of normal. Enrolled were 482 patients: 168 had exclusion criteria. Of the remaining 314 (age 64±11 years; 62% male), 254 (81%) had AMI: of these, 231 had BSPM STE—sensitivi...