Depression of atrium function by narcotics.
D000818:Animals; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006339:Heart Rate / Q000187:drug effects; D066298:In Vitro Techniques; D009020:Morphine / Q000494:pharmacology; D009270:Naloxone / Q000494:pharmacology; D009294:Narcotics / Q000494:pharmacology*
D009294:Narcotics; D009270:Naloxone; D009020:Morphine