title: The effect of exercise and heart rate on fibrinolytic activity.
abstract: The effect of heart rate on plasma fibrinolytic activity was investigated in nine patients with dual chamber cardiac pacemakers before and after 10 min of stimulated tachycardia to 123 beats/min. The results were compared to seven volunteers who performed submaximal exercise to 90% target heart rate and to five of the seven who underwent a second period of exercise to a heart rate of 120 beats/min. During submaximal exercise (mean heart rate 152 beats/min) the median ECLT fell from 248 min (interquartile range 147.5-305) to 90 (55-202) P less than 0.01 and t-PA:Ag increased from 6.1 ng/ml (3.92-7.95) to 9.3 (8.45-12.7), P less than 0.025. PAI and PAI-1:Ag fell from 12.0 IU/ml (5.85-15.5) to 4.1 (1.85-11.67), P less than 0.01, and 9.7 ng/ml (2.8-10.6) to 6.7 (2.1-9.9), P less than 0.01 respectively. A lower level of exercise to 120 beats/min resulted in a reduction in ECLT from 215 min (167.5-228.5) to 135 (116-154), P = 0.05 and an increase in t-PA:Ag from 4 ng/ml (3.07-4.45) to 5.0 (3.3-5.22) P less than 0.05. PAI and PAI-1:Ag fell from 7.6 IU/ml (3.27-8.5) to 7.1 (2.77-7.4) and from 7.7 ng/ml (6.0-7.92) to 6.4 (4.8-7.3) respectively but these changes were not statistically significant.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Academic Unit of Medicine, General Infirmary at Leeds, UK.
authors.forename: S C
authors.initials: SC
authors.lastname: Gough
authors.forename: S
authors.initials: S
authors.lastname: Whitworth
authors.forename: P J
authors.initials: PJ
authors.lastname: Rice
authors.forename: P J
authors.initials: PJ
authors.lastname: Grant
mesh_terms: D000328:Adult; D000368:Aged; D000941:Antigens / Q000032:analysis; D004558:Electric Stimulation; D015444:Exercise / Q000502:physiology*; D005260:Female; D005342:Fibrinolysis / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010138:Pacemaker, Artificial; D012016:Reference Values; D010959:Tissue Plasminogen Activator / Q000276:immunology / Q000378:metabolism
chemical_list: D000941:Antigens; D010959:Tissue Plasminogen Activator