Effect of urapidil on the performance of ischaemic myocardium in anaesthetized dogs.
The effect of urapidil on the ischaemic myocardium was studied in eight anaesthetized dogs. Stenosis of the left descending coronary artery reduced blood flow and systolic contraction of the post-stenotic myocardium by about 50%; the end-diastolic length of the post-stenotic myocardium and the end-diastolic pressure increased, while aortic pressure slightly decreased. Subsequent administration of urapidil (0.25 + 0.25 + 0.5 + 1.0 mg/kg intravenously) did not affect the systolic shortening and end-diastolic length of the myocardium supplied by the left circumflux coronary artery, while the stroke volume and the systolic shortening of the ischaemic myocardium increased. The latter was correlated with a decrease in the heart rate (r = -0.92), but not with the reduction in aortic pressure. Urapidil by itself does not impair the performance of the ischaemic myocardium, but might be beneficial in decreasing the heart rate or suppressing reflex tachycardia during reduction of the afterload.
Schad
H
H
Klinik für Herz- und Gefässchirurgie, Deutsches Herzzentrum München, Federal Republic of Germany.
Heimisch
W
W
Barankay
A
A
Hesse
S
S
Mendler
N
N
D000317:Adrenergic alpha-Antagonists / Q000627:therapeutic use*; D000818:Animals; D000959:Antihypertensive Agents / Q000627:therapeutic use*; D003327:Coronary Disease / Q000188:drug therapy* / Q000503:physiopathology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D004353:Drug Evaluation, Preclinical; D006439:Hemodynamics / Q000187:drug effects / Q000502:physiology; D010879:Piperazines / Q000627:therapeutic use*
D000317:Adrenergic alpha-Antagonists; D000959:Antihypertensive Agents; D010879:Piperazines; C015568:urapidil