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Hachimi-Idrissi S, Huyghens L. Advanced cardiac life support update: the new ILCOR cardiovascular resuscitation guidelines. International Liaison Committee on Resuscitation. Eur J Emerg Med 2002; 9:193-202. [PMID: 12131649 DOI: 10.1097/00063110-200206000-00020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- S Hachimi-Idrissi
- Department of Critical Care Medicine and Cerebral Resuscitation Research Group, Vrije Universiteit Van Brussel, Laarbeeklaan, 101, B-1090 Brussels, Belgium
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Abstract
As exemplified in this discussion of ACLS antiarrhythmic drugs, the evidence-based evaluation process has created a high standard for the acceptance and ranking of therapies for cardiac arrest. This process also has identified critical areas needing further investigation, fostered a healthy sense of discomfort with the adequacy of our present interventions for cardiac arrest, and hopefully will continue to spur the science while sifting the dogma out of CPR.
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Affiliation(s)
- Peter J Kudenchuk
- Division of Cardiology, Department of Medicine, University of Washington, Seattle, Washington, USA
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Tsuboi M, Chiba S. Effects of lidocaine on isolated, blood-perfused ventricular contractility in the dog. Heart Vessels 2000; 14:289-94. [PMID: 10901484 DOI: 10.1007/bf03257241] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Direct inotropic effects of lidocaine on ventricular muscle were investigated in isolated canine left ventricular preparations which were perfused with a donor dog's arterial blood. Intravenous administration of lidocaine in doses of less than 1 mg/kg did not cause any significant hemodynamic or cardiac changes in the donor dog and in the isolated ventricular preparation. A large dose of 10mg/kg of lidocaine produced a marked depressor response in the donor and a negative inotropic effect in the isolated ventricle. Direct injection of lidocaine (1-30 micromol) to the isolated preparation induced a dose-related decrease in the ventricular contractile force. Infusion of lidocaine (3 micromol/ml per min) did not influence norepinephrine- or calcium chloride-induced positive inotropic effects. In the frequency-force relationship, lidocaine generally depressed the contractility, exhibiting the positive staircase phenomenon. On the other hand, a calcium entry inhibitor, diltiazem, readily caused the negative staircase. From these results, it is concluded that (1) a large amount of lidocaine has a cardiac depressant property, (2) lidocaine has no antiadrenergic properties, and (3) the action of lidocaine may probably be due to the effect of intracellular calcium movement but not to a modification of Ca inward currents.
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Affiliation(s)
- M Tsuboi
- Department of Pharmacology, Shinshu University School of Medicine, Matsumoto, Japan
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Singh BN. Initial antiarrhythmic drug therapy during resuscitation from sudden cardiac death: a time for a fundamental change in strategy? J Cardiovasc Pharmacol Ther 2000; 5:3-9. [PMID: 10687668 DOI: 10.1177/107424840000500101] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abstract
Prompt cardiopulmonary resuscitation (CPR) and early defibrillation significantly improve the likelihood of successful resuscitation from cardiac arrest and are the key components in the American Heart Association's "chain of survival." Although representing current clinical practice in the United States, there is limited evidence supporting the benefit of acute administration of such antiarrhythmic medications as lidocaine, bretylium, magnesium, and procainamide to a victim of cardiac arrest. There has been only 1 published case-controlled clinical trial in which shock-refractory victims of out-of-hospital ventricular fibrillation were stratified into those who received lidocaine and those who did not. In this trial, no significant differences were observed between treatment groups in the return of an organized rhythm, admission to the hospital, or survival to hospital discharge. In the recently published ARREST trial, a significant improvement in admission alive to the hospital was observed in recipients of intravenous amiodarone, compared with placebo (44% vs 34%, respectively, p = 0.03). With the possible exception of intravenous amiodarone, available evidence of definitive benefit from antiarrhythmic drugs in cardiac arrest is inconclusive. Due to regulatory issues, clinical trials in cardiac arrest are extremely difficult to design and perform.
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Affiliation(s)
- P J Kudenchuk
- University of Washington, Division of Cardiology, Seattle 98195-6422, USA
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Kirlangitis J, Middaugh R, Knight R, Goglin W, Helsel R, Grishkin B, Briggs R. Comparison of bretylium and lidocaine in the prevention of ventricular fibrillation after aortic cross-clamp release in coronary artery bypass surgery. JOURNAL OF CARDIOTHORACIC ANESTHESIA 1990; 4:582-7. [PMID: 2132137 DOI: 10.1016/0888-6296(90)90408-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The authors compared bretylium and lidocaine for reducing the incidence and persistence of ventricular fibrillation following aortic cross-clamp release performed during coronary artery bypass surgery. Thirty-three adult patients scheduled for elective bypass surgery were randomly assigned in a double-blind fashion to receive a bolus of bretylium, 10 mg/kg, lidocaine, 2 mg/kg, or saline, in equal volumes prior to the release of the aortic cross-clamp. Coronary artery bypass surgery was conducted using standard cardiopulmonary bypass (CPB) procedures with systemic cooling to 24 degrees to 28 degrees C. Temperature, arterial blood gases, and electrolytes were recorded. After clamp release, the first electrical rhythm was noted. Abnormal rhythms (ventricular fibrillation) were allowed to persist for 1 to 2 minutes, and if spontaneous conversion to a supraventricular rhythm did not occur, defibrillation with internal DC countershocks was applied. Patients were compared with respect to occurrence of ventricular fibrillation, need for DC countershocks, antiarrhythmic drugs, and inotropic support. There was no significant difference among the groups with respect to age, sex, preoperative medications, past medical histories, ejection fractions, average number of bypasses, cross-clamp times, or temperatures during bypass. The incidence of ventricular fibrillation after aortic cross-clamp removal was: saline 91%, lidocaine 64% (P less than 0.01), and bretylium 36% (P less than 0.01). The number of countershocks required to defibrillate, while lower in the bretylium group, did not reach statistical significance. After cardiopulmonary bypass, cardiac output and systemic vascular resistance were comparable. Bretylium warrants further study in this setting.
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Affiliation(s)
- J Kirlangitis
- Department of Surgery, Brooke Army Medical Center, Fort Sam Houston, TX 78234-6200
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Chow MS, Kluger J, DiPersio DM, Lawrence R, Fieldman A. Antifibrillatory effects of lidocaine and bretylium immediately postcardiopulmonary resuscitation. Am Heart J 1985; 110:938-43. [PMID: 4061267 DOI: 10.1016/0002-8703(85)90188-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The antifibrillatory effects of lidocaine and bretylium in the postcardiopulmonary resuscitation (CPR) setting were examined using ventricular fibrillation threshold (VFT) determinations in anesthetized dogs. The dogs were fibrillated and CPR was carried out with a pneumatic device. Lidocaine and bretylium were administered intravenously at the onset of CPR, and VFT was serially determined after defibrillation following three consecutive 3-minute CPR periods. A dose of 2 mg/kg of lidocaine caused a significant increase in VFT determinations after the first but not subsequent 3-minute CPR periods; a dose of 1 mg/kg of lidocaine was ineffective at any time point. A dose of 5 mg/kg of bretylium elevated the VFT after the second and third but not the first 3-minute period. In dogs who received lidocaine, a significant elevation of VFT determinations were found to be associated with a high blood lidocaine concentration (mean 13.8 +/- 8.3 micrograms/ml). The present study demonstrates that a 2 mg/kg dose of lidocaine administered during CPR rapidly increases VFT determinations after CPR (within 5 minutes), whereas, a 5 mg/kg dose of bretylium significantly elevates VFT determinations but at a later time (within 10 minutes). The observed significant effect of lidocaine appears to be associated with high lidocaine blood concentrations (greater than 6 micrograms/ml).
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Temesy-Armos PN, Legenza M, Southworth SR, Hoffman BF. Effects of verapamil and lidocaine in a canine model of sudden coronary death. J Am Coll Cardiol 1985; 6:674-81. [PMID: 4031280 DOI: 10.1016/s0735-1097(85)80130-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The efficacy of verapamil and lidocaine for treating ischemia-induced arrhythmias was determined in a conscious canine model with a previous myocardial infarction remote from the ischemic area. Temporary (up to 5.5 minutes) occlusion of the circumflex coronary artery was made in eight conscious dogs that had sustained an anterior myocardial infarction 13 to 35 days previously. Each dog served as its own control. Ventricular arrhythmias were observed in 100% of control experiments but in only 25% of experiments after verapamil pretreatment at 0.4 mg/kg body weight. Repetitive ventricular complexes, defined as two or more consecutive ventricular complexes terminating spontaneously in sinus rhythm, were seen in 88% of control experiments and 13% of verapamil experiments, whereas ventricular fibrillation was seen in 6% of control experiments but in no verapamil experiment. Thus, verapamil abolished arrhythmias or reduced the grade of arrhythmias in all dogs. Six of the eight dogs were also tested with lidocaine pretreatment at one or two doses resulting in mean plasma levels of 3.8 +/- 2.0 micrograms/ml. Ventricular arrhythmias were seen in 92% of control experiments and 100% of lidocaine experiments. The incidence of ventricular fibrillation increased from 8% in control to 60% in lidocaine experiments. It is concluded that verapamil may prevent severe ischemia-induced arrhythmias after a recent myocardial infarction, whereas lidocaine may in some cases aggravate arrhythmias.
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Dunn HM, McComb JM, Kinney CD, Campbell NP, Shanks RG, MacKenzie G, Adgey AA. Prophylactic lidocaine in the early phase of suspected myocardial infarction. Am Heart J 1985; 110:353-62. [PMID: 3895875 DOI: 10.1016/0002-8703(85)90156-5] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Four hundred two patients with suspected myocardial infarction seen within 6 hours of the onset of symptoms entered a double-blind randomized trial of lidocaine vs placebo. During the 1 hour after administration of the drug the incidence of ventricular fibrillation or sustained ventricular tachycardia among the 204 patients with acute myocardial infarction was low, 1.5%. Lidocaine, given in a 300 mg dose intramuscularly followed by 100 mg intravenously, did not prevent sustained ventricular tachycardia, although there was a significant reduction in the number of patients with warning arrhythmias between 15 and 45 minutes after the administration of lidocaine (p less than 0.05). The average plasma lidocaine level 10 minutes after administration for patients without a myocardial infarction was significantly higher than that for patients with an acute infarction. The mean plasma lidocaine level of patients on beta-blocking agents was no different from that in patients not on beta blocking agents. During the 1-hour study period, the incidence of central nervous system side effects was significantly greater in the lidocaine group, hypotension occurred in 11 patients, nine of whom had received lidocaine, and four patients died from asystole, three of whom had had lidocaine. We cannot advocate the administration of lidocaine prophylactically in the early hours of suspected myocardial infarction.
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Abstract
Ventricular fibrillation (VF), in most instances, is sustained by multiple wavefronts. The most important prerequisites for development and maintenance of VF are inhomogeneity in activation and recovery and shortening of refractoriness. If drugs are to be effective in removing VF or facilitating its electrical removal, this should occur by alteration of these electrophysiologic mechanisms. Assessment of the antifibrillatory properties of many drugs has been compromised by at least two factors: 1) the questionable appropriateness of the model, and 2) the failure to distinguish between prevention of VF and removal, or facilitation of electrical removal, of VF. Most instances of VF encountered clinically are secondary to acute ischemia; therefore, the most applicable model is acute myocardial ischemia with spontaneous VF. In this setting little is known about the effectiveness of lidocaine (L) or procainamide (PA). While there is more information regarding the role of L in prevention of VF, and of both L and PA in elevating ventricular fibrillation threshold, there is a lack of data on the roles of either drug in removal of existing VF. Thus we are left to speculate on the actions of L and PA that may account for their usefulness in the treatment of VF. These actions are the basis for a projection of the role of L and PA in the treatment of VF. There is evidence in animal models of acute myocardial ischemia to support the use of at least lidocaine in VF.
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Siegel S, Brodman R, Fisher J, Matos J, Furman S. Intracardiac electrode detection of early or subendocardial ischemia. Pacing Clin Electrophysiol 1982; 5:892-902. [PMID: 6184692 DOI: 10.1111/j.1540-8159.1982.tb00028.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Subendocardial and early transmural ischemia may have significant clinical consequences while manifesting few ECG changes. Catheters were designed to be introduced transvenously into the right ventricle (RV), and coronary sinus (CS) and transarterially into the left ventricle (LV). The intracavitary electrodes were modified so that the electrodes would not contact the endocardium. In twenty-two dogs ninety-eight graded stenoses of the circumflex and left anterior descending coronary arteries were performed while electrograms (EGM) were recorded simultaneously from the intracardiac (IC) electrodes and surface ECG. Of those stenoses resulting in only nonspecific ECG changes, there were specific ischemic changes on 100% of LV, 60% of RV, and 89% of CS electrograms. Of those stenoses which resulted in no ECG change, there were specific ischemic changes in the 9/31 (29%) of LV, 3/31 (10%) of RV, and 6/31 (19%) of CS electrograms. Recognizable patterns of change occur on the intracardiac electrograms in response to both stenosis and reperfusion, earlier than any change on the ECG. Besides being more sensitive, intracardiac electrodes allowed for the detection of ischemia even in the presence of intraventricular conduction defects, strain patterns, and possibly other situations which might otherwise mask ischemic changes on the ECG.
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Kirlin PC, Romson JL, Pitt B, Abrams GD, Schork MA, Lucchesi BR. Ibuprofen-mediated infarct size reduction: effects on regional myocardial function in canine myocardial infarction in canine myocardial infarction. Am J Cardiol 1982; 50:849-56. [PMID: 7124645 DOI: 10.1016/0002-9149(82)91244-9] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Clusin WT, Bristow MR, Baim DS, Schroeder JS, Jaillon P, Brett P, Harrison DC. The effects of diltiazem and reduced serum ionized calcium on ischemic ventricular fibrillation in the dog. Circ Res 1982; 50:518-26. [PMID: 7067059 DOI: 10.1161/01.res.50.4.518] [Citation(s) in RCA: 68] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Calcium influx blockers reportedly suppress ventricular arrhythmias during acute ischemia. We therefore studied the effects of diltiazem and reduced serum ionized calcium on ventricular fibrillation (VF) in a reversible ligation model. VF was produced at 15-minute intervals by simultaneous occlusion of the left anterior descending and circumflex arteries of 31 dogs. Time from coronary occlusion to onset of VF showed no significant variation during 15 consecutive trials in six dogs that received saline alone. Intravenous infusion of diltiazem (0.02 mg/kg per min) markedly delayed the onset of VF in each of 10 dogs (P less than 0.0001). Mean VF latency increased from 138 to 295 seconds during a 45-minute diltiazem infusion, declined exponentially when the infusion ceased, and was strongly correlated with serum diltiazem concentration (r = 0.96, P less than 10(-6)). In five dogs, hemodynamic measurements, including coronary venous blood flow, were performed during each occlusion. The increase in VF latency by diltiazem was not due to increased coronary flow during occlusion or to reduction of left ventricular (LV) mechanical work. In six dogs, mean serum ionized calcium, [Ca++], was reduced from 1.11 to 0.59 mM by infusion of sodium citrate. Citrate infusion increased mean VF latency from 155 to 243 seconds, and the increase observed in each dog was correlated (r = 0.84, P less than 10(-6)) with the reduction in [Ca++]. VF latency was unaffected by lidocaine in nine dogs. The antifibrillatory effect of diltiazem during global LV ischemia may be an electrophysiological phenomenon related to reduction of cellular calcium influx.
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Cardinal R, Janse MJ, van Eeden I, Werner G, d'Alnoncourt CN, Durrer D. The effects of lidocaine on intracellular and extracellular potentials, activation, and ventricular arrhythmias during acute regional ischemia in the isolated porcine heart. Circ Res 1981; 49:792-806. [PMID: 7261273 DOI: 10.1161/01.res.49.3.792] [Citation(s) in RCA: 60] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Marshall RJ, Winslow E. The antidysrhythmic and cardiovascular effects of the aminosteroid, ORG 6001. GENERAL PHARMACOLOGY 1981; 12:315-22. [PMID: 7026350 DOI: 10.1016/0306-3623(81)90082-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
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Krämer B, Gülker H, Meesmann W. The effects of lidocaine on the ventricular fibrillation threshold and primary ventricular fibrillation following acute experimental coronary occlusion. Basic Res Cardiol 1981; 76:29-43. [PMID: 7236176 DOI: 10.1007/bf01908161] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Experiments were performed on 39 anaesthetized open-chest dogs (BW 16-33 kg) to examine the effect of lidocaine on the frequency of primary ventricular fibrillation (VF) and the time course of the ventricular fibrillation threshold (VFT) (train of stimuli-method) following acute coronary artery occlusion, and also to study the effects of lidocaine on the VFT of non-ischaemic heart at different therapeutic and high non-therapeutic doses. At effective plasma levels of lidocaine usually reached in clinical therapy (130-480 micrograms/l) there was no measurable increase in VFT compared to control values. The drop in VFT following acute ligation of the left anterior descending coronary artery (LAD) was neither eliminated nor even merely diminished. After occlusion of the left circumflex coronary artery (CIR), the incidence of spontaneous VF was not reduced in comparison to a control group. With regard to the doses administered and the plasma levels of lidocaine achieved, only the application of clinically extremely high or toxic doses resulted in increases in VFT in the non-ischaemic heart.
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Bussmann WD, Schreiber S, Kaltenbach M. Comparison of antiarrhythmic effects of oral prajmalium bitartrate and intravenous lidocaine in acute myocardial infarction. Am Heart J 1980; 99:589-97. [PMID: 7369098 DOI: 10.1016/0002-8703(80)90732-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
In 35 patients with acute myocardial infarction premature ventricular complexes were quantified from stored continuous electrocardiographic tape recordings using a semiautomated arrhythmia detection system. Seventeen patients, separated at random, received no antiarrhythmic drug and formed the control group. In nine patients prajmalium bitartrate was given orally at a dose of 60 mg. (20 mg. every 4 hours). Nine patients had permanent infusions of 2.1 mg./minute lidocaine (corresponding to a daily dose of 3 g.). In both treated groups premature ventricular complexes decreased significantly as compared to the spontaneous frequency in the control group. Six hours after the onset of therapy premature ventricular complexes were reduced to 37% of the initial value in the prajmalium bitartrate group and to 51% in the lidocaine group, whereas in the control group frequency increased (169%). The peak effect was reached after ten hours when premature ventricular complexes were reduced to 5% under prajmalium bitartrate and to 20% under lidocaine administration. Runs of premature ventricular complexes were nearly completely suppressed after administration of prajmalium bitartrate. Under lidocaine administration runs were moderately and not significantly reduced. Eight hours after the onset of therapy, runs were reduced to 8% of the initial value under prajmalium bitartrate and to only 79% under lidocaine. The effect of prajmalium bitartrate on runs of premature ventricular complexes was significantly more pronounced than the effect of lidocaine. The present study documents that orally administered prajmalium bitartrate is an alternative to intravenous administration of lidocaine in the treatment of ventricular arrhythmias after acute myocardial infarction.
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Marshall RJ, Parratt JR. Prophylactic lignocaine and early post-coronary artery occlusion dysrhythmias in anaesthetized greyhounds. Br J Pharmacol 1980; 71:597-600. [PMID: 7470764 PMCID: PMC2044446 DOI: 10.1111/j.1476-5381.1980.tb10978.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
1. Lignocaine (1 mg kg-1 min-1 infused intravenously for 30 min) greatly reduced the incidence of ventricular ectopic beats that resulted from acute coronary artery ligation in anaesthetized greyhound dogs. However, the incidence of ventricular fibrillation was only slightly reduced by this treatment which caused significant myocardial depression. 2. There is no good evidence from this study that lignocaine is a particularly effective prophylactic in acute myocardial infarction.
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Reynolds RD, Kamath BL. N-acetylprocainamide and ischemia-induced ventricular fibrillation in the dog. Eur J Pharmacol 1979; 59:115-9. [PMID: 92414 DOI: 10.1016/0014-2999(79)90032-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Open-chest dogs anesthetized with pentobarbital were treated with saline or N-acetylprocainamide (20 mg/kg, i.v.) 10 min prior to simultaneous ligation of the left anterior descending and septal coronary arteries. Ventricular fibrillation occurred in 20 of 26 control dogs but in only 6 of 15 dogs treated with N-acetylprocainamide (P less than 0.05). Since N-acetylprocainamide significantly reduced spontaneous heart rate this may have contributed to its antifibrillatory effect.
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Ribner HS, Isaacs ES, Frishman WH. Lidocaine prophylaxis against ventricular fibrillation in acute myocardial infarction. Prog Cardiovasc Dis 1979; 21:287-313. [PMID: 368880 DOI: 10.1016/0033-0620(79)90015-x] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Pearle DL, Williford D, Gillis RA. Superiority of practolol versus propranolol in protection against ventricular fibrillation induced by coronary occlusion. Am J Cardiol 1978; 42:960-4. [PMID: 727146 DOI: 10.1016/0002-9149(78)90682-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The ability of practolol and propranolol of prevent ventricular fibrillation in experimental anterior myocardial infarction was compared in dogs subjected to ligation of the left anterior descending and first septal coronary arteries. This procedure, which causes ventricular fibrillation in 90 percent of animals within 30 minutes, was performed in control dogs and in dogs pretreated with propranolol (0.5 mg/kg body weight) or with practolol (1.5 to 2.5 mg/kg). These doses produced nearly equivalent shifts in isoproterenol-induced chronotropic dose-response curves, indicating equivalent degrees of beta adrenergic blockade. In 21 dogs with confirmed ligation, cardiogenic shock did not develop. Six of seven control dogs died with ventricular fibrillation. Six of seven dogs pretreated with propranolol also had fibrillation, whereas only one of the seven dogs pretreated with practolol manifested ventricular fibrillation during the 45 minute postligation observation period. Practolol afforded significant protection compared with no treatment or treatment with propranolol (P less than 0.05).
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Harvie CJ, Collins GA, Miyagishima RT, Walker MJ. The action of prostaglandin E2 and F1alpha on myocardial ischaemia-infarction arrhythmias in the dog. PROSTAGLANDINS 1978; 16:885-99. [PMID: 748980 DOI: 10.1016/0090-6980(78)90104-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Prostaglandin E2 and F1alpha infusions have been tested for their ability to reduce the arrhythmias associated with occlusion of the left descending coronary artery in the anaesthetised dog. At 1 microgram/kg/min both PGs reduced the incidence of premature ventricular contractions occurring during 25-min occlusions, while not reducing the incidence of ventricular fibrillation occurring on occlusion release. When infused for 5-min periods at 1 to 16 microgram/kg/min, neither PGE2 nor PGF1alpha effectively reduced the frequency of ventricular arrhythmias occurring 24 hr after a permanent coronary occlusion.
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Abstract
The effect of lidocaine on the atrial fibrillation threshold (AFT) and the ventricular fibrillation threshold (VFT) was studied in anesthetized dogs. In ten animals, injection of lidocaine 2 mg./Kg. intravenously resulted in a markded increase of the ventricular fibrillation threshold (from 11.0 +/- 1.5 to 33.3 +/- 6.2 mA., P less than 0.001). In another group of ten animals, lidocaine did not have consistent effect on the atrial fibrillation threshold. However, a dose of lidocaine of 3 mg./Kg intravenously produced a significant increase in AFT (from 14.0 +/- 0.56 to 41.1 +/- 0.32 mA., P less than 0.001). No changes in AFT or VFT were noted in control experiments. The data suggest that lidocaine possesses an antiarrhythmic effect on the atria but higher than usual doses are required.
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Gülker H, Krämer B, Stephan K, Meesmann W. Changes in ventricular fibrillation threshold during repeated short-term coronary occlusion and release. Basic Res Cardiol 1977; 72:547-62. [PMID: 588206 DOI: 10.1007/bf01910416] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The time course of changes in VFT was determined during the 1st phase of arrhythmia following coronary occlusion and during consecutive reperfusion in five repeated periods of occlusion and reperfusion in 10 mongrel dogs (17--24 kg). VFT was determined using a square wave pulse series of 140 ms duration which was triggered by the R-wave of the ECG and placed into the vulnerable period of the cardiac cycle. After acute occlusion VFT decreased to a minimum level within a few minutes and then increased again slowly up to the control value which was reached about 20 min after the ligation. When the occlusions were repeated several times the extent of the decrease in VFT became increasingly less and its duration increasingly shorter until finally there was no significant decrease in VFT. Reperfusion after coronary occlusion led to an abrupt decrease in VFT within 1 min, followed by a rapid increase to the control value. This time course did not depend upon the number of prior occlusions. The results show that in the case of repeating short-term coronary occlusions one cannot expect comparable VFT time courses for the consecutive periods of occlusion except for the 1st and 2nd ones. Differing mechanisms leading to the occurrence of VF after coronary ligation and during reperfusion are discussed.
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