Blood rheology as a contributing factor in reduced coronary reserve in systemic hypertension.
The influence of blood fluidity on coronary reserve in patients with essential hypertension and normal coronary arteries was examined. The coronary reserve, expressed as the ratio of coronary vascular resistance under resting conditions to the coronary vascular resistance after administration of dipyridamole, was 4.1 +/- 1.5 in 10 normotensive patients with normal coronary arteries, whereas the mean value was only 2.4 +/- 0.8 in 35 hypertensive patients. When compared with the normotensive control group the 35 hypertensive patients had significantly higher levels of hematocrit (45.9 +/- 3.7 vs 42.3 +/- 3.6; p less than or equal to 0.01) and plasma viscosity (1.39 +/- 0.07 vs 1.32 +/- 0.06 mPas; p less than 0.01). Plasma fibrinogen (291 +/- 67 vs 251 +/- 25 mg/dl) and whole blood viscosity at a shear rate of 2 s-1 (7.77 +/- 1.1 vs 7.21 +/- 1.28 mPas) and at a high shear rate of 100 s-1 (4.23 +/- 0.57 vs 3.91 +/- 0.64 mPas) demonstrated a trend without statistical significance toward higher values in hypertensive patients. When the hypertensive group was further divided according to the coronary reserve (less than 2.5, severely impaired coronary reserve; greater than 2.5 less than 3.8, moderately impaired coronary reserve), the parameters of blood fluidity clearly correlated inversely with coronary reserve. This suggests a major importance of rheologic abnormalities on impaired coronary reserve in hypertensive patients.
Leschke
M
M
Department of Medicine, Heinrich-Heine University of Duesseldorf, Federal Republic of Germany.
Vogt
M
M
Motz
W
W
Strauer
B E
BE
D000787:Angina Pectoris / Q000097:blood / Q000503:physiopathology; D001794:Blood Pressure; D001809:Blood Viscosity / Q000502:physiology*; D003326:Coronary Circulation / Q000502:physiology; D003331:Coronary Vessels / Q000503:physiopathology*; D005260:Female; D005340:Fibrinogen / Q000032:analysis; D006400:Hematocrit; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010949:Plasma / Q000502:physiology; D012212:Rheology; D014655:Vascular Resistance / Q000502:physiology*
D005340:Fibrinogen