Effects of remifentanil on the contractility of failing human heart muscle.
OBJECTIVE
The purpose of this study was to determine the direct effects of remifentanil on inotropy of human myocardial tissue removed from failing explanted hearts of cardiac transplant recipients.


METHODS
In vitro, prospective study with repeated measures.


METHODS
Research laboratory in a tertiary referral center.


METHODS
The authors studied the effects of remifentanil on isometric myocardial contractile parameters in failing atrial and ventricular myocardial muscles. The authors also used 1 micromol/L of isoproterenol to test adrenergic responsiveness of failing myocardial tissues in the presence of supratherapeutic remifentanil concentrations.


RESULTS
Muscles were studied at 37 degrees C and 1 Hz, with concentrations of remifentanil covering a wide range of therapeutic as well as supratherapeutic concentrations (ie, between 0.001 and 100 microg/mL). After the dose-response curve was obtained, the author measured the inotropic response to 1 micromol/L of isoproterenol in the presence of the cumulative dose of remifentanil. Over the wide range of concentrations, remifentanil had no significant effect on contractile function. In the presence of supratherapeutic concentration of remifentanil, isoproterenol produced a 97% +/- 58% increase in developed tension in failing atrial muscles and a 91% +/- 40% increase in failing ventricular muscles, which did not significantly differ from control muscles.


CONCLUSIONS
The authors showed that remifentanil had no significant negative inotropic effects in failing human heart muscle and that myocardial contractility remained fully responsive to beta-adrenergic stimulation at all remifentanil concentrations studied.
Ogletree
Monique L
ML
Division of Pediatric Cardiovascular Anesthesiology, Texas Children's Hospital and Baylor College of Medicine, Houston, TX, USA.
Sprung
Juraj
J
Moravec
Christine S
CS
D000318:Adrenergic beta-Agonists; D000328:Adult; D000368:Aged; D018686:Anesthetics, Intravenous / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005260:Female; D006321:Heart / Q000187:drug effects*; D006333:Heart Failure / Q000503:physiopathology*; D006801:Humans; D066298:In Vitro Techniques; D007537:Isometric Contraction / Q000187:drug effects; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D009200:Myocardial Contraction / Q000187:drug effects*; D010880:Piperidines / Q000494:pharmacology*; D000077208:Remifentanil
D000318:Adrenergic beta-Agonists; D018686:Anesthetics, Intravenous; D010880:Piperidines; D007545:Isoproterenol; D000077208:Remifentanil