[Effect of hemorheological factors on coronary flow during myocardial ischemia].
Intracoronary infusion of some drugs may induce superimposed coronary vasodilation upon endogenous vasodilation during myocardial ischemia, which was suggested as coronary vasodilator reserve. For an investigation of this phenomenon, 8 pigs were anesthetized, chest-opened, LAD (left anterior descending coronary artery)-dissected and instrumented. The LAD pressure was reduced to 4.67 kPa (35mmHg), and then intracoronary infusion of adenosine, saline, or anisodamine (at the same rate of 2ml/min) was started and maintained for 9 minutes. The three solutions all produced a significant increase in the coronary flow, including the saline (compared with the control, P < 0.05). The hemorheological examination of the distal coronary blood revealed a reduced hematocrit, plasma viscosity and whole blood viscosity during the saline and anisodamine infusion periods (P < 0.05), but in the adenosine infusion, the statistical analysis on hemorheological data revealed no significance compared with the control (P > 0.05). The results showed that the coronary vasodilator reserve induced by intracoronary drugs during myocardial ischemia might be partly accounted by regional hemodilution in the LAD bed. The study suggested that a decrease in blood viscosity might play an important role in the improvement of the narrowed coronary circulation, even more important than vasodilator drugs.
Wang
S
S
Shen
X
X
Li
X
X
Huang
N
N
He
X
X
D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D001809:Blood Viscosity / Q000187:drug effects; D003326:Coronary Circulation; D005260:Female; D018056:Hemorheology / Q000187:drug effects*; D008297:Male; D017202:Myocardial Ischemia / Q000097:blood / Q000503:physiopathology*; D012991:Solanaceous Alkaloids / Q000494:pharmacology; D013552:Swine; D014665:Vasodilator Agents / Q000494:pharmacology
D012991:Solanaceous Alkaloids; D014665:Vasodilator Agents; C003922:anisodamine; D000241:Adenosine