thiopental and Atrial-Flutter

Sixteen ASA class II or III male patients (aged, 52 to 66 years) undergoing elective cardioversion were randomly assigned to receive either thiopental or etomidate according to an observer-blinded, parallel study design. The appropriate drug was administered in 2-mL aliquots every 15 seconds until the patient no longer responded to verbal commands, at which time cardioversion was attempted. The total dose for induction was 0.22 +/- 0.2 mg/kg and 3.2 +/- 0.4 mg/kg for etomidate and thiopental, respectively. The cardiorespiratory data after induction were evaluated for maximal percent change from baseline. The baseline heart rate was 106 +/- 6 beats/min and 98 +/- 8 beats/min for the etomidate and thiopental groups, respectively (mean +/- SEM). The heart rate decreased 5% after induction with etomidate and increased 7% with thiopental (P less than 0.05). The baseline mean arterial pressure (MAP) was 96 +/- 3 mm Hg and 105 +/- 11 mm Hg for the etomidate and thiopental groups, respectively (mean +/- SEM). The MAP decreased 4% with etomidate and 3% with thiopental. Respiratory rate was significantly increased by 22% after etomidate compared with a 22% decrease in respiratory rate with thiopental (P less than 0.05). Seven of eight patients in the thiopental group required only one countershock, whereas four of eight patients in the etomidate group required only one shock. One patient in each group could not be successfully cardioverted. Recovery time and clinical side effects were similar between groups except for mild myoclonus in the etomidate group. Titration to effect of either etomidate or thiopental provided satisfactory anesthesia for elective cardioversion in hemodynamically stable patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Aged; Anesthesia, Intravenous; Arrhythmias, Cardiac; Atrial Fibrillation; Atrial Flutter; Electric Countershock; Etomidate; Humans; Male; Middle Aged; Prospective Studies; Thiopental

Elective cardioversion is a short procedure performed under general anesthesia for the treatment of cardiac dysrhythmias. Selection of the anesthetic agent is important, because a short duration of action and hemodynamic stability are required. Forty-four patients scheduled for elective cardioversion in the coronary care unit were studied prospectively. All patients were randomly assigned, according to the last digit of their clinical record number, to receive one of the four anesthetic agents studied: group 1, 12 patients who received 3 mg/kg of sodium thiopental; group 2, 10 patients who received 0.15 mg/kg of etomidate; group 3, 12 patients who received 1.5 mg/kg of propofol; and group 4, 10 patients who received 0.15 mg/kg of midazolam. All patients also received 1.5 micrograms/kg of fentanyl 3 minutes before induction. All four drugs provided satisfactory anesthesia for cardioversion and there were no major complications. Midazolam produced a more prolonged duration of effect and more interindividual variability. Propofol was associated with hypotension and a higher incidence of apnea, and its duration of action was similar to that of etomidate or thiopental. Etomidate produced myoclonus and pain on injection; however, it was the only agent that did not decrease arterial blood pressure. Thiopental reduced blood pressure but otherwise seemed an appropriate anesthetic for this procedure. In conclusion, all four anesthetic agents were acceptable for cardioversion, although their pharmacological differences suggest specific indications for individual patients.

Topics: Adult; Aged; Anesthesia, Intravenous; Arrhythmias, Cardiac; Atrial Fibrillation; Atrial Flutter; Electric Countershock; Etomidate; Female; Humans; Male; Midazolam; Middle Aged; Propofol; Prospective Studies; Thiopental

Atrial tachyarrhythmias (AT) frequently complicate the perioperative period. Alcohol intoxication is a recognized causative factor for dysrrhythmias. We studied the effects of propofol and thiopental on atrial electrophysiology and vulnerability to AT in a closed-chest porcine model in which AT are facilitated by ethanol.. Thirty-eight pigs were randomly assigned to thiopental (T-group, n=19) or propofol (P-group n=19). All animals were assigned to undergo a right atrial electrical stimulation protocol (RASP) at baseline. Thirty pigs were assigned to undergo additional RASP during ethanol infusion, while the remaining eight were assigned to undergo additional RASP during saline infusion (control group). We analysed effective refractory period (ERP), and intra-atrial conduction interval (ICI) (between atrial sites 4 cm apart), at several cycle lengths (CL).. There were no significant differences at baseline. During ethanol infusion, propofol produced a greater rate-dependent decrease in excitability, manifested by a longer minimum paced CL with 1:1 atrial capture: 145 (11) vs 164 (27) ms in the T- and P-group, respectively (P=0.01). Propofol was associated with a greater rate-related slowing in conduction: difference between ICI at CL of 300 ms and ICI at minimum CL: 30 ms in P-group and 22 ms in T-group (P<0.03). In the P-group we observed a longer duration of induced arrhythmias (145 (131) vs 74 (91) s, P<0.03) and a higher proportion with atrial flutter (AFl) (76 vs 19%, P<0.001).. Propofol in this model was more arrhythmogenic than thiopental, as manifested by a longer duration of induced arrhythmias, particularly AFI.

Topics: Alcoholic Intoxication; Anesthetics, Intravenous; Animals; Arrhythmias, Cardiac; Atrial Flutter; Atrial Function, Right; Disease Models, Animal; Electrophysiology; Ethanol; Propofol; Random Allocation; Swine; Thiopental

Topics: Adult; Anesthesia; Atrial Flutter; Atrioventricular Node; Barbiturates; Electric Countershock; Electrocardiography; Female; Heart Conduction System; Humans; Male; Middle Aged; Recurrence; Thiopental

The efficacy of electroimpulsive therapy with low energy discharges (up to 50 joules) in various paroxysmal arrhythmias was studied. A mild tranquilizer, seduxen (diazenam), was used as the anesthetic. Electroimpulsive therapy with low-energy discharges was found to produce a high effect in ventricular tachycardia and atrial flutter but a poor restorative effect in atrial fibrillation. The possibility of successful anesthesia with seduxen in electrical cardioversion of paroxysmal disorders of cardiac rhythm is concretized.

Topics: Adult; Aged; Anesthesia; Arrhythmias, Cardiac; Atrial Fibrillation; Atrial Flutter; Diazepam; Electric Countershock; Electrocardiography; Female; Humans; Male; Middle Aged; Propanidid; Tachycardia, Paroxysmal; Thiopental

Topics: Anesthesia; Anesthetics; Arrhythmias, Cardiac; Atrial Flutter; Atropine; Electric Countershock; Electric Stimulation Therapy; Electroconvulsive Therapy; Humans; Mental Disorders; Methohexital; Propanidid; Succinylcholine; Tachycardia; Thiopental; Ventricular Fibrillation

Topics: Anesthesia; Anesthesiology; Atrial Fibrillation; Atrial Flutter; Electric Countershock; Humans; Tachycardia; Thiopental