Exercise-induced ST-segment depression in inferior leads during treadmill exercise testing and coronary artery disease

The exercise electrocardiogram is a commonly used non-invasive and inexpensive method for detection of electrocardiogram (ECG) changes secondary to myocardial ischemia. Reversible ST-segment depression is the characteristic finding associated with exercise-induced, demand-driven ischemia in patients with significant coronary obstruction but no flow limitation at rest. The exercise-induced ST-segment depression in inferior leads has been questioned and it has been reported that lead V5 alone consistently outperforms the inferior leads and the combination of lead V5 with II, because lead II has a high false-positive rate. A review of the 12-lead visual electrocardiographic interpretations confirmed that changes isolated to the inferior leads were rare in patients, who had no diagnostic Q waves. Considering the sum of ST-segment depression or the most depression in the three leads representing the three main areas of the myocardium (II, V2, and V5) did not improve the diagnostic capacity of the test. A case is presented to illustrate how in a patient, the ST-segment depression in inferior leads during exercise testing is related with significant coronary artery disease. We present a case of exercise-induced ST-segment depression in inferior leads in a 52 year-old Italian man. This experience demonstrates that ST-segment depression in inferior leads during the exercise testing can have a diagnostic significance.