Value of lead aVR in the detection of significant left main coronary artery stenosis in acute coronary syndrome

Background: Electrocardiographic lead aVR is usually ignored in patients with chest pain. ST segment elevation in aVR may have diagnostic value in patients with acute coronary syndrome (ACS) and significant stenosis or obstruction of the left main coronary artery (LMCAS), especially when accompanied by ST segment elevation in lead V1.Aim: To asses the value of lead aVR and V1 for the detection of LMCAS in patients with ACS.Methods: The study group consisted of 150 patients (mean age 60.6±9.5 years, range 33-78 years) with ACS, including 46 with LMCAS and 104 without LMCAS. ECG recordings obtained on admission were compared between these two groups.Results.: In patients with LMCAS, ST segment elevation in lead aVR was two times more frequent than in remaining patients (69.6% vs 34.6% p=0.0001) whereas there were no differences in lead V1. Sensitivity of ST elevation in aVR in detection of LMCAS was 69.6%, specificity - 65.4%, positive predictive value - 47.1%, and negative predictive value - 82.9%. In patients with LMCAS, ST segment depression was significantly more often present in ECG leads other than aVR (45.6% vs 23.1%