MAXIMAL PRECORDIAL ST-SEGMENT DEPRESSION IN LEADS V4-V6 IN PATIENTS WITH INFERIOR WALL ACUTE MYOCARDIAL-INFARCTION INDICATES CORONARY-ARTERY DISEASE INVOLVING THE LEFT ANTERIOR DESCENDING CORONARY-ARTERY SYSTEM

Background: In inferior wall acute myocardial infarction, maximal ST-s egment depression in left precordial leads (V4-V6) has been shown to b e associated with increased in-hospital mortality, presumably due to c oronary artery disease involving the left anterior descending coronary artery system. Methods: We measured ST-segment deviation from baselin e in the initial electrocardiogram of patients with inferior wall acut e myocardial infarction, who subsequently underwent coronary angiograp hy during their in-hospital stay. Patients were divided into three gro ups: (I) No precordial ST-segment depression (n=34). (II) Maximal prec ordial ST-segment depression in leads V1-V3 (n=44). (III) Maximal prec ordial ST-segment depression in leads V4-V6 (n=14). Results: The left anterior descending coronary artery or its diagonal branch were stenos ed (>50%) in 32%, 41%, and 71% of patients in groups I, II, and III, r espectively (p=0.04), and severely stenosed (>70%) in 18%, 18% and 57% of patients in the respective groups (p=0.007). Conclusion: In patien ts with inferior wall acute myocardial infarction, maximal precordial ST-segment depression in leads V4-V6 is suggestive of severe coronary artery disease involving the left anterior descending coronary artery or its diagonal branch. Copyright (C) 1997 Elsevier Science Ireland Lt d.