Effect of intravenous adenosine on human atrial and ventricular repolarisation.
OBJECTIVE
The aim was to assess the effects of therapeutic doses of intravenous adenosine on human atrial and ventricular repolarisation.


METHODS
The effects of 6 mg and 12 mg bolus doses of adenosine on the atrial and ventricular monophasic action potentials were studied using the contact catheter technique in 19 patients undergoing routine diagnostic electrophysiology studies. The effect on atrial repolarisation was studied before and after beta blockade in a subgroup of patients.


RESULTS
The duration of the monophasic action potential to 90% repolarisation (MAPD90) was measured in all cases. After 6 mg of adenosine the atrial MAPD90 shortened from 227(SD 29) ms to 188(25) ms (p < 0.005); after 12 mg it shortened from 221(31) ms to 168(32) ms (p < 0.001). The maximum shortening was unaltered by propranolol 0.15 mg.kg-1. The ventricular MAPD90 showed no significant change after 12 mg, at 240(32) ms v 234(33) ms.


CONCLUSIONS
Therapeutic doses of adenosine shorten the atrial but not the ventricular monophasic action potential duration. The effect is dose dependent and not abolished by beta blockade.
Nunain
S O
SO
Department of Cardiological Sciences, St George's Hospital Medical School, London, United Kingdom.
Garratt
C
C
Paul
V
V
Debbas
N
N
Ward
D E
DE
Camm
A J
AJ
D000200:Action Potentials / Q000187:drug effects*; D000241:Adenosine / Q000008:administration & dosage* / Q000494:pharmacology; D001281:Atrial Fibrillation / Q000139:chemically induced; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D006321:Heart / Q000187:drug effects*; D006325:Heart Atria / Q000187:drug effects; D006352:Heart Ventricles / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D011433:Propranolol / Q000494:pharmacology
D011433:Propranolol; D000241:Adenosine