Following successful angioplasty of the right coronary lesion, the exercise test was repeated. The ECG shown here was recorded immediately following exercise. It is now normal with no evidence of ST segment depression. It indicates that the diffuse exercise-induced ST segment depression was the result of non-transmural (or sub-endocardial) ischemic in the region supplied by the stenotic right coronary artery and that this ischemic region was not identified by the leads in which the ST segment depression was present.