BACKGROUND: Current guidelines for exercise training in coronary patients state that in the presence of exercise-induced ischemia, the heart rate during exercise should be at least 10 beats/min below the heart rate associated with an ST segment depression of 1 mm or greater. For patients with a relatively low ischemic threshold, this recommendation does not allow for a sufficient training stimulus. OBJECTIVE: To document the effects of a single session of exercise above the ischemic threshold on biochemical markers of myocardial injury in stable coronary patients with exercise-induced ischemia. Because creatine kinase (CK) and its MB isoenzyme (CK-MB) can both increase after exercise because of skeletal muscle injury, troponin T was also measured. METHODS: Twenty-one patients with documented coronary artery disease underwent two 20 min exercise sessions. The intensity of the first exercise training session was fixed at a heart rate below the ischemic threshold (ie, approximately 10 beats/min lower than the heart rate associated with the appearance of an ST segment depression of 1 mm or greater). The intensity of the second exercise session was fixed at a heart rate above the ischemic threshold. RESULTS: Blood test measurements at baseline, 6 h after and 24 h after the exercise sessions did not show any increase in total CK, CK-MB or troponin. The value of all measurements remained well below the lower limits associated with myocardial damage. CONCLUSION: A 20 min period of exercise above the ischemic threshold did not result in myocardial necrosis.
BACKGROUND: Current guidelines for exercise training in coronary patients state that in the presence of exercise-induced ischemia, the heart rate during exercise should be at least 10 beats/min below the heart rate associated with an ST segment depression of 1 mm or greater. For patients with a relatively low ischemic threshold, this recommendation does not allow for a sufficient training stimulus. OBJECTIVE: To document the effects of a single session of exercise above the ischemic threshold on biochemical markers of myocardial injury in stable coronary patients with exercise-induced ischemia. Because creatine kinase (CK) and its MB isoenzyme (CK-MB) can both increase after exercise because of skeletal muscle injury, troponin T was also measured. METHODS: Twenty-one patients with documented coronary artery disease underwent two 20 min exercise sessions. The intensity of the first exercise training session was fixed at a heart rate below the ischemic threshold (ie, approximately 10 beats/min lower than the heart rate associated with the appearance of an ST segment depression of 1 mm or greater). The intensity of the second exercise session was fixed at a heart rate above the ischemic threshold. RESULTS: Blood test measurements at baseline, 6 h after and 24 h after the exercise sessions did not show any increase in total CK, CK-MB or troponin. The value of all measurements remained well below the lower limits associated with myocardial damage. CONCLUSION: A 20 min period of exercise above the ischemic threshold did not result in myocardial necrosis.
Authors: G F Fletcher; G J Balady; E A Amsterdam; B Chaitman; R Eckel; J Fleg; V F Froelicher; A S Leon; I L Piña; R Rodney; D A Simons-Morton; M A Williams; T Bazzarre Journal: Circulation Date: 2001-10-02 Impact factor: 29.690
Authors: J Myers; N Buchanan; D Walsh; M Kraemer; P McAuley; M Hamilton-Wessler; V F Froelicher Journal: J Am Coll Cardiol Date: 1991-05 Impact factor: 24.094
Authors: Arthur S Leon; Barry A Franklin; Fernando Costa; Gary J Balady; Kathy A Berra; Kerry J Stewart; Paul D Thompson; Mark A Williams; Michael S Lauer Journal: Circulation Date: 2005-01-25 Impact factor: 29.690
Authors: I L Geft; M C Fishbein; K Ninomiya; J Hashida; E Chaux; J Yano; J Y-Rit; T Genov; W Shell; W Ganz Journal: Circulation Date: 1982-12 Impact factor: 29.690