Myocardial ischemia during physical exercise in patients with stable coronary artery disease: predictability and prevention.
OBJECTIVE
We assessed whether exercise-induced myocardial ischemia during intensive group exercise sessions can be predicted in patients with coronary artery disease and stable angina pectoris.


RESULTS
Twenty-three patients underwent cardiac catheterization, 201-thallium scintigraphy, and exercise testing prior to participation in group training sessions. Heart rates and myocardial ischemia were documented by Holter monitoring. The individual training heart rate was calculated as a percentage of the maximal heart rate achieved during symptom-limited exercise testing. Myocardial ischemia occurred significantly more often during group exercise sessions (15 of 23 patients) than during treadmill testing (4 of 23 patients, P<0.001). Maximal heart rate (145+/-23 vs. 134+/-21 beats/min, P<0.004) and maximal plasma lactate concentrations (6.0+/-2.9 vs. 4.3+/-2.0 mmol/l, P<0.05) were significantly higher than during symptom-limited exercise testing. Ischemic episodes occurred significantly more often during jogging than during competitive ball games or interval training. Myocardial ischemia occurred in patients who exceeded their individual target training heart rates (43 of 44 episodes; P<0.001). Duration of ischemic episodes did not correlate with any marker obtained at the beginning of the study.


CONCLUSIONS
These data demonstrate that routine diagnostic procedures do not sufficiently identify patients at risk for exercise-induced myocardial ischemia. Ischemic events are only effectively prevented by choosing adequate types of exercise and, above all, by the strict adherence to individual target heart rates.
Hauer
K
K
Medizinische Universitätsklinik Heidelberg, Abteilung Innere Medizin III-Kardiologie, Heidelberg, Germany.
Niebauer
J
J
Weiss
C
C
Marburger
C
C
Hambrecht
R
R
Schlierf
G
G
Schuler
G
G
Zimmermann
R
R
Kübler
W
W
D017023:Coronary Angiography; D003327:Coronary Disease / Q000534:rehabilitation*; D005080:Exercise Test; D005081:Exercise Therapy / Q000009:adverse effects*; D005260:Female; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D011237:Predictive Value of Tests
D019344:Lactic Acid