title: Changes in human coronary flow reserve after administration of intracoronary diltiazem.
abstract: Epicardial coronary artery diameter (ECAD), coronary blood flow velocity (CBFV), and coronary flow velocity reserve (CFVR) were analyzed at baseline and after a 500 micrograms i.c. bolus of diltiazem in nonstenotic coronary arteries of awake humans. Furthermore, patients (n = 25) were first randomized to pretreatment either with placebo (n = 12) or isosorbide dinitrate (0.5 micrograms/kg/min infusion) (n = 13). Diltiazem resulted in a significant increase in epicardial diameter (+10%; p = 0.001) and in coronary blood flow (CBF) (+30%; p = 0.0001). Whereas basal CBFV only slightly increased (+7%; NS), there was a significant fall in CFVR (-11%; p = 0.001). The increase in coronary diameter and CBF after administration of i.c. diltiazem was comparable in placebo- and nitrate-pretreated patients. The decrease in CFVR, however, was restricted to the placebo-pretreated patients (-21%; p = 0.0004). Apparently, diltiazem attenuated the CFVR but only in the absence of nitrates. Thus, diltiazem i.c. appears to enhance myocardial oxygen supply without deleterious effects on the distal coronary perfusion pressure.
authors.affiliation: Department of Cardiology, University Hospital Gasthuisberg, Leuven, Belgium.
authors.forename: M C
authors.initials: MC
authors.lastname: Vrolix
authors.forename: D
authors.initials: D
authors.lastname: Sionis
authors.forename: J
authors.initials: J
authors.lastname: Piessens
authors.forename: J
authors.initials: J
authors.lastname: Van Lierde
authors.forename: J L
authors.initials: JL
authors.lastname: Willems
authors.forename: H
authors.initials: H
authors.lastname: De Geest
mesh_terms: D001783:Blood Flow Velocity / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D003331:Coronary Vessels / Q000187:drug effects; D006801:Humans; D007269:Injections, Intra-Arterial; D009566:Nitrates / Q000627:therapeutic use
chemical_list: D009566:Nitrates