Characteristics of transient ischaemic episodes in patients with silent and symptomatic exercise-induced myocardial ischaemia.

To evaluate transient ischaemic episodes during daily life in patients with coronary artery disease and exercise-induced myocardial ischaemia, 38 patients underwent ambulatory ST-segment monitoring over 48 h. Sixteen patients had painless ischaemia during exercise and occasional angina, and 12 patients had symptomatic ischaemia and frequent angina during daily life. Ten patients with proven coronary artery disease but normal exercise electrocardiograms served as controls. The extent of coronary artery lesions and the prevalence of myocardial infarction were similar in all groups. ST-segment monitoring revealed 817 min and 98 episodes of ST depression in 13/16 patients of the asymptomatic group and 111 min and 21 episodes in 5/12 patients of the symptomatic group (P less than 0.03). Subjective scores for physical activity during Holter monitoring were significantly higher in the first group than in the second. The majority of ischaemic episodes in both groups was asymptomatic. No ischaemic ST changes occurred in control patients. Results indicate a higher frequency of transient ischaemic episodes related to a higher level of physical activity in patients with silent ischaemia than in patients with symptomatic exercise-induced ischaemia.