An automated algorithm to improve ECG detection of posterior STEMI associated with left circumflex coronary artery occlusion

The under-recognition, underestimate of area at risk, and under-treatment of ST elevation posterior myocardial infarct in patients with acute coronary syndrome are often due to the insensitive standard 12-lead electrocardiographic diagnosis and bias toward "anterior subendocardial ischemia". We designed a new computer algorithm to improve ECG detection of isolated and combined posterior myocardial infarct using extended posterior leads V7, V8 and V9. ECG criteria for PMI include "age" (acute, recent, age indeterminate or old) and "probability" (consider, probable or definite) infarct. Combining the subjects with posterior myocardial infarct (n=182), we obtained an increase of 26 percentage points in sensitivity of posterior myocardial infarction detection from 14% using standard 12-leads to 40% including posterior leads with a small drop in specificity from 98% to 96.4%. The highest increase was seen in a subset of subjects having undergone for PTCA procedure from 21% to 86% (65 percentage points). We conclude the automated posterior myocardial infarct detection algorithm provides another valuable tool for diagnosis of ST elevation posterior myocardial infarct. Posterior leads V7, V8 and V9 can capture ECG changes due to isolated ST elevation PMI or acute myocardial infarct with posterior wall involvement and provide improved sensitivity in posterior myocardial infarct detection.