Dose-related effects of intracoronary application of nisoldipine on central and peripheral circulatory parameters.
In a randomized study central and peripheral circulatory parameters were determined in 12 anaesthetized mongrel dogs before and after intracoronary injection of nisoldipine and placebo. Administration of 0.2 to 0.8 micrograms/kg nisolpine was followed by a 46% to 62% decrease in coronary vascular resistance and a 109% to 141% increase in myocardial blood flow lasting 10 min. There was no significant change in myocardial contractility or peripheral circulatory parameters. An increase in dosage to 1.6 micrograms/kg did not cause a further increase in myocardial blood flow or decrease in coronary vascular resistance. However, there was a significant decrease in total peripheral resistance of up to 32% and a 36% increase in heart rate attributable to counter-regulation lasting 3 to 5 min. At this dosage level a significant decrease in myocardial contractility and an increase in left ventricular end-diastolic pressure are to be expected. This implies a major dissociation between coronary vascular effects and changes in parameters of myocardial performance and peripheral resistance after intracoronary administration of nisoldipine, an effect which is dose-related. Injection of 0.4 to 0.8 micrograms/kg would seem to be the optimal dosage range for intracoronary administration of nisoldipine producing maximum coronary dilatation without myocardial depression.
Department of Cardiology, Universitätsklinikum Rudolf Virchow der Freien Universität, Berlin, Germany.
M
M
Schartl
C
C
Heidelmeyer
S
S
Veit
C
C
Dougherty
J B
JB
Brückner
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D007267:Injections; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D009543:Nifedipine / Q000031:analogs & derivatives* / Q000494:pharmacology; D015737:Nisoldipine; D012039:Regional Blood Flow / Q000187:drug effects*; D014655:Vascular Resistance / Q000187:drug effects
D002121:Calcium Channel Blockers; D015737:Nisoldipine; D009543:Nifedipine