ISCHEMIC-LIKE ST-SEGMENT CHANGES DURING HOLTER MONITORING IN PATIENTSWITH ANGINA-PECTORIS AND NORMAL CORONARY-ARTERIES BUT NEGATIVE EXERCISE TESTING

To evalutate whether Holter electrocardiographic monitoring may improv e the detection of ST-segment depression in patients with anginal ches t pain and normal coronary arteries, we performed symptom-limited exer cise testing and 24-hour Holter monitoring in a group of 38 such patie nts (27 women, age 54 +/- 8 years). Patients were divided into 2 group s: group X1 included 28 patients with and group X2 10 patients without significant ST-segment depression during exercise testing. There were no significant differences between the 2 groups in age, gender, chara cteristics of chest pain, exercise duration, heart rate (HR), and bloo d pressure at peak exercise, but anginal pain during exercise testing was reported by 10 patients of group X1 (36%) and 9 of group X2 (90%) (p < 0.01). Episodes of ST-segment depression on Holter monitoring wer e found in 17 patients of group X1 (61%) and in 5 patients of group X2 (50%) (p = NS). There were no differences between the 2 groups in dai ly number of ST episodes (3.6 +/- 4 vs 2.8 +/- 5 episodes per patient) , symptomatic episodes (8% vs 18%), and duration of the episodes. On a verage, HR increased significantly, in a similar way, from 15 minutes before ST-segment depression to 1-mm ST in both groups, and its value at the onset of ischemia was similar in the 2 groups (102 +/- 22 vs 10 9 +/- 18 beats/min, p = NS). Finally, HR at 1-mm ST during Holter moni toring was significantly lower than that observed at 1-mm ST during ex ercise testing (127 +/- 16 beats/min, p less than or equal to 0.01) in group X1, and it was also lower than that observed at peak exercise ( 136 +/- 22 beats/min, p less than or equal to 0.01) in group X2. In co nclusion, Holter monitoring can significantly Increase the detection o f ST-segment depression in patients with anginal pain and normal coron ary arteries, indicating a cardiac, although not necessarily ischemic, origin of the pain. Indeed, 50% of our patients with negative symptom -limited exercise testing showed spontaneous ST changes, compatible wi th transient myocardial ischemia, during daily activities. Differences in the response of coronary microvascular tone to exercise testing an d to stimuli operating during daily life are likely to play a signific ant role in determining these findings. (C) 1997 by Excerpta Medica, I nc.