title: Dipyridamole slows the rate of isovolumic pressure fall in patients with normal coronary arteries.
abstract: Dipyridamole is currently used for thallium imaging and stress echocardiography. The coronary and haemodynamic effects of dipyridamole are well documented while its effects on left ventricular relaxation remain to be determined. The aim of the present study was to evaluate the effects of dipyridamole on left ventricular relaxation rate in healthy subjects. High fidelity pressure recordings were obtained at fixed atrial pacing (89 +/- 2 beats.min-1) in 10 subjects with normal left ventricular angiography and coronary arteriograms. Left ventricular pressure was recorded at rest and 5 min after a 4 min infusion of dipyridamole (0.14 mg.kg-1.min-1). Dipyridamole infusion decreased left ventricular systolic pressure (P < 0.01) and time to left ventricular systolic pressure (P < 0.01), with no changes in end-diastolic pressure or peak rate of pressure rise. The peak rate of isovolumic pressure fall decreased (from 1957 +/- 105 to 1488 +/- 100 mmHg.s-1, P < 0.01) and the time constant of isovolumic relaxation increased (from 37 +/- 2 to 44 +/- 3 ms, P < 0.02). In conclusion, our study indicates that acute administration of clinically relevant doses of dipyridamole displays deleterious effects on heart relaxation in healthy humans.
authors.affiliation: Département de Physiologie et d'Hémodynamique, Hôpital Bichat, Paris, France.
authors.forename: A
authors.initials: A
authors.lastname: Nitenberg
authors.forename: Y
authors.initials: Y
authors.lastname: Lecarpentier
authors.forename: I
authors.initials: I
authors.lastname: Antony
authors.forename: D
authors.initials: D
authors.lastname: Chemla
mesh_terms: D001158:Arteries; D001794:Blood Pressure / Q000187:drug effects*; D003331:Coronary Vessels / Q000187:drug effects* / Q000502:physiology; D004176:Dipyridamole / Q000494:pharmacology*; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects; D012016:Reference Values; D013599:Systole
chemical_list: D004176:Dipyridamole