Association Between Angina Pectoris and Ischemic Indexes During Exercise Testing and Ambulatory Monitoring

Abstract

We examined the relation between anginal symptoms and ischemic indexes during ischemia on exercise testing and daily activities in 76 patients (59 men and 17 women, mean age 61.5 years) with documented coronary artery disease and exercise-induced ischemia. All patients underwent upright bicycle exercise testing and 48-hour ambulatory electrocardiographic monitoring (AECG). Angina was reported in 28 patients (37%) during exercise-induced ischemia. A total of 287 ischemic episodes were detected from 44 patients (58%) during AECG. There was a mean number of 7.4 episodes and a mean total duration of 75 min/48 hours. There were no differences in the prevalence and the magnitude of ambulatory ischemia between patients with and without angina during exercise testing. Among the 44 patients who had ischemia during both tests, 50% of patients with angina during exercise testing had symptomatic ischemia during AECG compared to 14% in patients with silent ischemia during exercise testing (p = 0.01). Ninety-two percent of ischemic episodes were preceded by an increase in heart rate (HR) of >10 beats/min. There was a strong positive correlation (r = 0.70, p <0.01) between HR at onset of 1 mm ST depression (ischemic threshold) during exercise testing and during AECG. We conclude that (1) patients with exercise-induced angina have significantly more symptoms during ambulatory ischemia, (2) ischemic threshold during exercise testing and daily life are positively correlated, and (3) our findings emphasize the role of increased myocardial oxygen demand in the development of ambulatory ischemia. (Am J Cardiol 1996;78:266–270)