[Clinical significance of fibrinolytic system defectiveness in exercise induced myocardial ischemia and its mechanism].
Plasma levels of tissue type plasminogen activator (tPA), plasminogen activator inhibitor (PAI), fibrinogen (Fg), thromboxane B2 (TXB2), 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha), renin activity (PRA) and angiotensin II (ANGII) were assayed in 18 patients with coronary heart disease and 11 healthy subjects before and after submaximal treadmill exercise test according to "Bruce programme". All patients showed significant (> or = 50%) stenosis of at least one branch of the coronary arteries in coronary angiography and normal levels of serum trinitroglycerin. Drugs of dipyridamole, heparin, warfarin and aspirin were not administered to the patients two weeks before the test. The results were as follows: (1) Plasma PAI activity and Fg levels in 12 patients with positive test were remarkablly higher than in the remaining 6 subjects with negative test in the CHD group and in the control before and after exercise. Plasma tPA antigen changed in a reverse way. (2) Plasma levels of TXB2, PRA and ANGII in the positive test subgroup of CHD were higher than in the negative test subgroup and in the control after exercise, but differences of the parameters among the three groups were insignificant before exercise. The study suggests that defectiveness of fibrinolytic system in CHD patients was shown mainly as disorder of tPA-PAI equilibrium and that decreased fibrinolytic activity and increased PAI in exercise-induced myocardial ischemia have relations with activation of platelets and renin-angiotensin system.
Deng
H
H
Department of Cardiology, Air Force Guangzhou Hospital, Guangzhou.
Guo
H
H
Qian
X
X
D000804:Angiotensin II / Q000097:blood; D003327:Coronary Disease / Q000097:blood*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015849:Plasminogen Inactivators / Q000097:blood*; D012084:Renin-Angiotensin System / Q000502:physiology; D010959:Tissue Plasminogen Activator / Q000097:blood*
D015849:Plasminogen Inactivators; D000804:Angiotensin II; D010959:Tissue Plasminogen Activator