Abstract 13260: Relationship Between Localization of Myocardial Asynergy and Presence of Pathological Q Wave in Synthetic Posterior Lead Electrocardiogram

Abstract

Background: Synthesized posterior lead derived from 12-lead ECG can represent ST elevation in posterior acute myocardial infarction with high accuracy. However, the validity of pathological Q wave (Q) in synthesized lead ECG remained unclear. Objective: To investigate the relationship between localization of ventricular wall motion abnormality (Asynergy) and presence of Q in synthetic V7-V9 lead (synV7-V9). Subjects: Consecutive 1319 walk-in patients (68±13y, Male 67.5%, LVEF 64.0±10.4%) who underwent ECG and transthoracic echocardiography (TTE) were extracted from our database. Method: (1) Posterior lead: synV7-V9 was obtained from synECi18 system (Nihon Kohden) and V2-V5, II•aVF, and I•aVL•V6 leads were obtained from 12-lead ECG. (2) Asynergy was detected as increased wall motion score on 16-segments from TTE and classified into coronary perfusion regions. We analyzed the relationship between Q in synV7-V9 and patient characteristics, ECG parameters, or TTE parameters. Results: Wall motion abnormality was observed in 217 cases (16.5%). Q in synV7-V9 was detected in 79 cases (6.0%), and 38 cases out of them showed asynergy in any coronary perfusion site (Figure. A). In order to clarify relationship between Q in synV7-V9 and asynergy, wall motion score of 16-segments were compared in Presence of Q in synV7-V9 limited group and Non Q in all lead group (Figure. B). As a result, in the former, the scores in basal to mid on inferior to infero-lateral wall were found to be significantly higher. Logistic regression analysis for presence of Q in synV7-V9 limited showed asynergy in RCA to LCx region (OR 4.5, 95%CI 1.6-13.0), in RCA region (OR 4.0, 95%CI 1.4-11.0), in LCx region (OR 5.8, 95%CI 1.2-27.7), male (OR 2.6, 95%CI 1.2-6.0), right bundle brunch block (OR 3.2, 95%CI 1.4-7.3) remained as significant factors. Conclusion: Present study suggests Q in posterior lead using synthesized ECG can help diagnose myocardial scarring in RCA to LCx region including posterior wall.