Systemic vasodilatation following diazepam after combined sympathetic and parasympathetic blockade in patients with coronary heart disease.
Clinical and hemodynamic benefits have been documented after giving diazepam to patients with coronary heart disease. The mechanisms by which this agent produces its hemodynamics effects are poorly understood. Partial autonomic blockade was induced in 10 patients by the intravenous administration of 5 mg propranolol and 0.8 mg atropine. Coronary and systemic hemodynamics were normal before and unchanged (p greater than 0.05) after propranolol and atropine administration. However, myocardial extraction of lactate improved in 9 out of 10 patients (from 11% to 24%, p less than 0.05). The patients then received 0.1 mg/kg diazepam intravenously. Diazepam had no effect on the coronary sinus blood flow and resistance while myocardial extraction of lactate further improved in all but one patient (from 24% to 35% at 5 min and 34% at 15 min, p less than 0.05). Heart rate increased by a mean of 4 beats at 5 min (p less than 0.01). Cardiac output was unchanged. Systolic arterial pressure (SAP) decreased significantly (p less than 0.001) at 5 and 15 min (6-10%) and left ventricular end-diastolic pressure (LVEDP) also diminished significantly (p less than 0.001) at 5 and 15 min (18-19%). These changes occurred despite autonomic blockade. These findings suggest, in the absence of change of myocardial blood flow and contractility, a direct peripheral action of the drug on arteries and/or veins.
D000328:Adult; D001285:Atropine / Q000494:pharmacology* / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003327:Coronary Disease / Q000188:drug therapy* / Q000378:metabolism / Q000503:physiopathology*; D003975:Diazepam / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology* / Q000627:therapeutic use; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007275:Injections, Intravenous; D007773:Lactates / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology* / Q000627:therapeutic use; D014665:Vasodilator Agents; D014666:Vasomotor System / Q000187:drug effects*
D007773:Lactates; D014665:Vasodilator Agents; D001285:Atropine; D011433:Propranolol; D003975:Diazepam