There are several potential causes for the occurrence of myocardial ischaemia after successful coronary angioplasty, but the role of ambulatory electrocardiographic monitoring, particularly in the detection of coronary restenosis, remains undefined in these patients. Previous studies have shown that ambulatory monitoring demonstrates ST-segment changes in only a minority of patients before, and rarely after, successful angioplasty. The presence of transient myocardial ischaemia, whether symptomatic or silent, on ambulatory electrocardiographic monitoring has not been shown to relate to the outcome, frequency of complications, or rate of restenosis in patients after successful angioplasty. Ambulatory electrocardiographic monitoring and exercise testing are complementary investigative techniques for the detection of myocardial ischaemia after successfully coronary angioplasty. Their roles will depend on the type of ischaemic syndrome present, its presentation and the pathophysiological mechanisms involved.