title: Effects of nitrous oxide on systolic time intervals.
abstract: The effects of inhalation of oxygen, nitrous oxide/oxygen and nitrous oxide/nitrogen/oxygen on systolic time intervals (PEP (pre-ejection period) and LVET (left ventricular ejection time) were investigated in eight healthy persons. Nitrous oxide 40%, administered with oxygen or oxygen/nitrogen, prolonged PEP significantly by 25% and 22%, respectively. Inhalation of oxygen also prolonged PEP but to a significantly minor degree. LVET, heart rate and MAP were unchanged during the experiments. Derivatives from the systolic time intervals, i.e. PEP/LVET, I/PEP2 and ejection fraction changed significantly in the nitrous oxide groups. It is concluded that nitrous oxide depresses cardiac performance, to some degree, even when administered at a rather low concentration.
mesh_terms: D000328:Adult; D000769:Anesthesia, Inhalation; D001794:Blood Pressure / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D009584:Nitrogen / Q000494:pharmacology; D009609:Nitrous Oxide / Q000494:pharmacology*; D010100:Oxygen / Q000494:pharmacology; D013599:Systole / Q000187:drug effects*; D013997:Time Factors
chemical_list: D009609:Nitrous Oxide; D009584:Nitrogen; D010100:Oxygen