The value of lead aVR in identifying the infarct-related artery in patients with acute inferior myocardial infarction

Objective:To investigate the electrocardiography(ECG) criteria for identifying the infarct-related artery (IRA) in patients with acute inferior myocardial infarction(MI).Method: We retrospectively studied 90 patients with acute inferior MI hospitalized between July 2002 to December 2004. The ECG recorded within 24 h of the onset of symptoms were analyzed. Result:There were 70 patients whose IRA were right coronary artery (RCA) and 20 patients whose IRA were left circumflex artery (LCX) among the 90 patients. ST-segmet elevation in lead Ⅰ and/or ST-segment depression in lead V_1 and V_2 indicated that IRA were LCX; ST-segment more elevated in lead Ⅲ than in lead Ⅱ and/or ST-segment elevation ≥~0.5 mm in lead V_4R implied that IRA were RCA; ST-segment depression≥1 mm in lead aVR had a sensitivity of ~70.0 percent, a specificity of ~94.3 percent for identifying LCX as IRA.Conclusions:ST-segment elevation in lead Ⅰ, ST-segment more elevated in lead Ⅲ than in lead Ⅱ, ST-segment depression or elevation in lead V_1 and V_2 ST-segment elevation ≥~0.5 mm in lead V_4R and ST-segment depression≥1 mm in lead aVR, above 5 criteria can be used for identifying IRA in patients with acute inferior MI. The presence of ST-segment depression in lead aVR is a new criterion.