Values of electrocardiography and two-dimensional echocardiography to identify myocardial infarction due to left circumflex and right coronary artery disease.
To investigate the value of the 12-lead ECG and two-dimensional echocardiography (2DE) in the distinction of left circumflex (LCX) from right coronary artery (RCA) disease, we analyzed the location of Q waves, infarct lesions, and coronary artery narrowings in 26 patients with angiographically documented single-vessel disease. Q waves in leads II, III, and aVF were associated with the posterior wall (PW) lesions at the papillary muscle level. Extensive lesions from the PW to the posterior septum (PS) identified RCA disease, while extension to the lateral wall (LW) identified LCX disease. Eleven of 12 patients with high posterior infarction (tall R wave in V1) were found to have extensive LW lesions and 10 of these had coronary narrowings in or proximal to the obtuse marginal branch of LCX. All 6 patients with high posterior infarction and high lateral infarction (Q in I or aVL) had infarct lesions extending from the LW to the anterior wall (AW) and were associated with LCX disease with a large obtuse marginal branch. Of 10 patients with Q waves in V6, the apical LW and PW were involved in 7 and either segment in 3. Nine of these 10 patients had LCX disease. It is concluded that the location of Q waves in inferior infarction could aid in recognizing infarct extension and underlying coronary artery disease.
D000328:Adult; D000368:Aged; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000473:pathology; D004452:Echocardiography; D004562:Electrocardiography; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000175:diagnosis* / Q000473:pathology