Disappearance of exercise-induced ST-segment depression associated with transient left anterior hemiblock

To our knowledge, this is the first case reported of total disappearance of exercise-induced ST-segment depression in the presence of transient left anterior hemiblock at peak exercise. An unusual paradoxic increase in T-wave amplitude was also noticed. The significant ST-segment displacement reappeared when the transient left anterior hemiblock disappeared during the recovery phase. Based on current review, the presence of transient left anterior hemiblock during exercise seems to correlate well with the proximal left anterior descending coronary artery disease. Therefore, the presence of transient left anterior hemiblock during exercise with either normalization of exercise-induced ST-segment depression or paradoxic increase in T-wavse amplitude at peak level may be a useful end-point to stop the test for patients who do not reach 2 mm ST-segment depression or who remain asymptomatic.