The value of ST-segment elevation in lead aVR for predicting left main coronary artery lesion in patients suspected of acute coronary syndrome.

UNLABELLED: The use of lead aVR for predicting appearance of left main coronary artery (LMCA) lesion has been recently a subject of great interest. This study evaluates the predictive value of ST-segment elevation in lead aVR on electrocardiogram in the diagnosis of significant LMCA lesions.

METHODS: The study population consisted of 400 consecutive patients admitted within 6 hours from the onset of typical chest pain to coronary care unit (CCU). Electrocardiogram was recorded after the admission to emergency ward. ST segment elevation in aVR lead was measured and coronary angiography was performed within 48 hours admission to CCU.

RESULTS: Overall, 31% of suspected patients had ST segment elevation in aVR lead that elevation more than 0.1 mv was observed in 34.7% of all subjects. High incidence of ST segment elevation > 0.1 mv was seen in the group with left main lesion so that 40.7% of men and 43.8% of women with (LMCA) lesion had ST segment elevation > 0.1 mv. There was a significant relationship between the incidence of ST segment elevation > 0.1 mv and the number of diseased coronary vessels in men. However, this relation was not observed in women. Different risk profile of ACS did not influence the incidence of the ST-segment elevation in aVR lead. Compared with coronary angiography, ST-segment elevation in lead aVR in ECG had a sensitivity of 62.7%, a specificity of 73.6%, a positive predictive value of 25.8%, and a negative predictive value of 93.1% in predicting LMCA disease.

CONCLUSION: ST-elevation of lead aVR is a valuable indicator for predicting LMCA lesion with acceptable accuracy and predictive value.