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British journal of pharmacology1970; 39(1); 149-159; doi: 10.1111/j.1476-5381.1970.tb09564.x

Influence of halothane and catecholamines on heart rate and rhythm in the horse.

Abstract: 1. Ventricular ectopic beats were recorded in eight of thirteen conscious horses following the intravenous administration of adrenaline in doses of 3 mug/kg. Following pre-treatment with either atropine sulphate (0.1 mg/kg) or propranolol hydrochloride (0.1 mg/kg), the same dose level of adrenaline failed to produce ventricular ectopic beats.2. Halothane anaesthesia sensitized the equine heart to the arrhythmogenic actions of adrenaline; the incidence and duration of ventricular arrhythmias being greater than in conscious animals. In comparison with the findings in conscious horses, ether anaesthesia appeared to protect the heart against adrenaline-induced arrhythmias.3. From a comparison of the arrhythmogenic, chronotropic and pressor actions of adrenaline, noradrenaline and isoprenaline during halothane anaesthesia, it was concluded that sensitization to the arrhythmogenic actions of catecholamines resulted primarily from the action of halothane on the ventricle. The results also indicated that the pressor responses to catecholamines during halothane anaesthesia probably played some part in the genesis of arrhythmias.4. No "spontaneous" ventricular arrhythmias were recorded in twenty-four horses anaesthetized with halothane or in sixteen animals under ether anaesthesia.5. The available evidence indicates that a moderate to fairly severe degree of hypercapnia produced little increase in sympathetic control of the myocardium during halothane anaesthesia; the absence of irregularities in ventricular rhythm during halothane anaesthesia were attributed to this factor.
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Publication Date: 1970-05-01 PubMed ID: 5420092PubMed Central: PMC1703061DOI: 10.1111/j.1476-5381.1970.tb09564.xGoogle Scholar: Lookup
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  • Journal Article

Summary

This research summary has been generated with artificial intelligence and may contain errors and omissions. Refer to the original study to confirm details provided. Submit correction.

This study investigates how the anesthetic drug halothane and substances known as catecholamines such as adrenaline, impact the heart rate and rhythm in horses, determining that halothane can make the heart more responsive to the irregular rhythm-causing effects of adrenaline.

Procedure and Findings

  • The study recorded abnormal heartbeats called ventricular ectopic beats in eight out of thirteen awake horses that were given adrenaline through the vein. However, once these horses had been pre-treated with other drugs (atropine sulphate or propranolol hydrochloride), the same amount of adrenaline did not cause these ectopic beats.
  • The study found that under halothane anesthesia, the horse’s heart became more prone to irregular rhythms caused by adrenaline. The presence and duration of these irregular heart rhythms were greater than in horses that were not under anesthesia. Comparatively, anesthesia with ether appeared to provide some heart protection against these adrenaline-induced arrhythmias.

Comparison of Adrenaline, Noradrenaline, and Isoprenaline effects under Halothane Anesthesia

  • The effects of the adrenaline, noradrenaline, and isoprenaline on the heart rate, rhythm, and blood pressure were compared under halothane anesthesia. The researchers concluded that the increased susceptibility to abnormal heart rhythms caused by these chemicals was largely due to the halothane’s impact on the ventricles of the heart. The study also suggested that the changes in blood pressure response to these chemicals during halothane anaesthesia may play a role in the development of these irregularities.

Spontaneous Ventricular Arrhythmias and Hypercapnia

  • No spontaneous ventricular arrhythmias were recorded in twenty-four horses anaesthetized with halothane or in sixteen animals under ether anesthesia.
  • They also found that moderate to fairly severe hypercapnia – elevated carbon dioxide levels in the blood – led to little increase in sympathetic control of the myocardium (the middle layer of heart muscle) during halothane anaesthesia. The researchers attributed the absence of irregular heartbeats during halothane anaesthesia to this.

Cite This Article

APA
Lees P, Tavernor WD. (1970). Influence of halothane and catecholamines on heart rate and rhythm in the horse. Br J Pharmacol, 39(1), 149-159. https://doi.org/10.1111/j.1476-5381.1970.tb09564.x

Publication

British journal of pharmacology
ISSN: 0007-1188
NlmUniqueID: 7502536
Country: England
Language: English
Volume: 39
Issue: 1
Pages: 149-159

Researcher Affiliations

Lees, P
    Tavernor, W D

      MeSH Terms

      • Anesthesia, Inhalation
      • Animals
      • Arrhythmias, Cardiac / chemically induced
      • Atropine / pharmacology
      • Catecholamines / pharmacology
      • Consciousness
      • Epinephrine / administration & dosage
      • Ethers
      • Female
      • Halothane / pharmacology
      • Heart Rate / drug effects
      • Horses
      • Hypercapnia / physiopathology
      • Isoproterenol / pharmacology
      • Male
      • Norepinephrine / pharmacology
      • Propranolol / pharmacology

      References

      This article includes 17 references
      1. MUIR BJ, HALL LW, LITTLEWORT MC. Cardiac irregularities in cats under halothane anaesthesia.. Br J Anaesth 1959 Nov;31:488-9.
        pubmed: 14425047doi: 10.1093/bja/31.11.488google scholar: lookup
      2. RAVENTOS J. The action of fluothane; a new volatile anaesthetic.. Br J Pharmacol Chemother 1956 Dec;11(4):394-410.
        pubmed: 13383118doi: 10.1111/j.1476-5381.1956.tb00007.xgoogle scholar: lookup
      3. RIKER WF Jr, ROBERTS J, STANDAERT F, KIM YUNG IN. The initiation and pharmacologic reactivity of a ventricular pacemaker in the intact animal.. J Pharmacol Exp Ther 1956 Aug;117(4):374-84.
        pubmed: 13358049
      4. Johnstone M. Propranolol (inderal) during halothane anaesthesia.. Br J Anaesth 1966 Jul;38(7):516-29.
        pubmed: 5943808doi: 10.1093/bja/38.7.516google scholar: lookup
      5. BLACK GW, LINDE HW, DRIPPS RD, PRICE HL. Circulatory changes accompanying respiratory acidosis during halothane (fluothane) anaesthesia in man.. Br J Anaesth 1959 Jun;31:238-46.
        pubmed: 13801149doi: 10.1093/bja/31.6.238google scholar: lookup
      6. Tavernor WD, Lees P. The influence of propranolol on cardiovascular function in conscious and anaesthetized horses.. Arch Int Pharmacodyn Ther 1969 Jul;180(1):89-99.
        pubmed: 5357013
      7. WYANT GM, MERRIMAN JE, KILDUFF CJ, THOMAS ET. The cardiovascular effects of halothane.. Can Anaesth Soc J 1958 Oct;5(4):384-402.
        pubmed: 13585168doi: 10.1007/BF03021139google scholar: lookup
      8. VASKO KA. Preliminary report on the effects of halothane on cardiac action and blood pressure in the horse.. Am J Vet Res 1962 Mar;23:248-50.
        pubmed: 13925024
      9. BURNAP TK, GALLA SJ, VANDAM LD. Anesthetic, circulatory and respiratory effects of fluothane.. Anesthesiology 1958 May-Jun;19(3):307-20.
        pubmed: 13533912doi: 10.1097/00000542-195805000-00001google scholar: lookup
      10. RIKER WF, DEPIERRE F, ROBERTS J, ROY BB, REILLY J. The epinephrine and hydrocarbon-epinephrine disturbance in the cat.. J Pharmacol Exp Ther 1955 May;114(1):1-9.
        pubmed: 14392564
      11. Lees P, Tavernor WD. The influence of suxamethonium on cardiovascular and respiratory function in the anaesthetized horse.. Br J Pharmacol 1969 May;36(1):116-31.
        pubmed: 5768082doi: 10.1111/j.1476-5381.1969.tb08309.xgoogle scholar: lookup
      12. DETERLING RA Jr, NGAI SH, LARAGH JH, PAPPER EM. The cardiovascular effects of continuous intravenous infusion of norepinephrine, epinephrine and neosynephrine during cyclopropane and ether anesthesia in the dog.. Anesthesiology 1954 Jan;15(1):11-8.
        pubmed: 13124791doi: 10.1097/00000542-195401000-00003google scholar: lookup
      13. Purchase IF. Cardiac arrhythmias occurring during halothane anaesthesia in cats.. Br J Anaesth 1966 Jan;38(1):13-22.
        pubmed: 5907304doi: 10.1093/bja/38.1.13google scholar: lookup
      14. MOORE EN, MORSE HT, PRICE HL. CARDIAC ARRHYTHMIAS PRODUCED BY CATECHOLAMINES IN ANESTHETIZED DOGS.. Circ Res 1964 Jul;15:77-82.
        pubmed: 14196208doi: 10.1161/01.res.15.1.77google scholar: lookup
      15. PAYNE JP, SENFIELD RM. PRONETHALOL IN TREATMENT OF VENTRICULAR ARRHYTHMIAS DURING ANAESTHESIA.. Br Med J 1964 Mar 7;1(5383):603-4.
        pubmed: 14088314doi: 10.1136/bmj.1.5383.603google scholar: lookup
      16. Black GW, Clarke RS, Howard PJ, McCullough H. The cardiovascular effects of teflurane in the cat.. Br J Anaesth 1969 Apr;41(4):288-96.
        pubmed: 5780732doi: 10.1093/bja/41.4.288google scholar: lookup
      17. STEPHEN CR, GROSSKREUTZ DC, LAWRENCE JH, FABIAN LW, BOURGEOIS-GAVARDIN M, COUGHLIN J. Evaluation of fluothane for clinical anaesthesia.. Can Anaesth Soc J 1957 Jul;4(3):246-58.
        pubmed: 13446767doi: 10.1007/BF03014423google scholar: lookup

      Citations

      This article has been cited 3 times.
      1. Coudry V, Jean D, Desbois C, Tnibar A, Laugier C, George C. Myocardial fibrosis in a horse with polymorphic ventricular tachycardia observed during general anesthesia. Can Vet J 2007 Jun;48(6):623-6.
        pubmed: 17616061
      2. Blaze CA, Robinson NE. Apneic oxygenation in anesthetized ponies and horses. Vet Res Commun 1987;11(3):281-91.
        doi: 10.1007/BF00570926pubmed: 3114941google scholar: lookup
      3. Rezakhani A, Edjtehadi M, Szabuniewicz M. Prevention of thiopental and thiopental/halothane cardiac sensitization to epinephrine in the sheep. Can J Comp Med 1977 Oct;41(4):389-95.
        pubmed: 922556
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