Biomaterial Database

Cardiac conduction interactions of propranolol and verapamil with halothane in pentobarbitone-anaesthetized dogs. 1988

A P Hart, and R L Royster, and W E Johnston

Department of Anaesthesia, Wake Forest University Medical Centre, Bowman Gray School of Medicine, Winston-Salem, NC 27103.

We have studied the effects of propranolol 0.25 mg kg-1 and verapamil 0.075 mg kg-1 on cardiac conduction and refractoriness in 21 dogs anaesthetized with pentobarbitone 30 mg kg-1 using His bundle electrocardiography and programmed stimulation. After baseline studies under pentobarbitone and halothane (1.3 MAC) anaesthesia, the dogs were allocated randomly to two groups: group 1 received verapamil followed by propranolol; group 2 received propranolol followed by verapamil; the drugs were given in a continuous infusion over 10 min. The atrial-His (AH) interval, the atrioventricular node effective (AVERP), and functional (AVFRP) refractory periods, were prolonged by verapamil in both groups, but not the His-ventricle (HV) interval or the ventricular effective refractory period (VERP). AVFRP and VERP were prolonged by propranolol in both groups. Corrected sinus node recovery times were normal after each drug. Heart rate and the rate required to produce Wenckebach were decreased by each drug. The combination of verapamil and propranolol during halothane anaesthesia in dogs has significant cardiac conduction effects; however, no spontaneous AV block occurred during the study.

UI	MeSH Term	Description	Entries
D010424	Pentobarbital	A short-acting barbiturate that is effective as a sedative and hypnotic (but not as an anti-anxiety) agent and is usually given orally. It is prescribed more frequently for sleep induction than for sedation but, like similar agents, may lose its effectiveness by the second week of continued administration. (From AMA Drug Evaluations Annual, 1994, p236)	Mebubarbital,Mebumal,Diabutal,Etaminal,Ethaminal,Nembutal,Pentobarbital Sodium,Pentobarbital, Monosodium Salt,Pentobarbitone,Sagatal,Monosodium Salt Pentobarbital
D011433	Propranolol	A widely used non-cardioselective beta-adrenergic antagonist. Propranolol has been used for MYOCARDIAL INFARCTION; ARRHYTHMIA; ANGINA PECTORIS; HYPERTENSION; HYPERTHYROIDISM; MIGRAINE; PHEOCHROMOCYTOMA; and ANXIETY but adverse effects instigate replacement by newer drugs.	Dexpropranolol,AY-20694,Anaprilin,Anapriline,Avlocardyl,Betadren,Dociton,Inderal,Obsidan,Obzidan,Propanolol,Propranolol Hydrochloride,Rexigen,AY 20694,AY20694,Hydrochloride, Propranolol
D012032	Refractory Period, Electrophysiological	The period of time following the triggering of an ACTION POTENTIAL when the CELL MEMBRANE has changed to an unexcitable state and is gradually restored to the resting (excitable) state. During the absolute refractory period no other stimulus can trigger a response. This is followed by the relative refractory period during which the cell gradually becomes more excitable and the stronger impulse that is required to illicit a response gradually lessens to that required during the resting state.	Period, Neurologic Refractory,Periods, Neurologic Refractory,Refractory Period, Neurologic,Tetanic Fade,Vvedenskii Inhibition,Wedensky Inhibition,Inhibition, Vvedenskii,Inhibition, Wedensky,Neurologic Refractory Period,Neurologic Refractory Periods,Neuromuscular Fade,Neuromuscular Transmission Fade,Refractory Period, Neurological,Refractory Periods, Neurologic,Electrophysiological Refractory Period,Electrophysiological Refractory Periods,Fade, Neuromuscular,Fade, Neuromuscular Transmission,Fade, Tetanic,Neurological Refractory Period,Neurological Refractory Periods,Refractory Periods, Electrophysiological,Refractory Periods, Neurological,Transmission Fade, Neuromuscular
D004285	Dogs	The domestic dog, Canis familiaris, comprising about 400 breeds, of the carnivore family CANIDAE. They are worldwide in distribution and live in association with people. (Walker's Mammals of the World, 5th ed, p1065)	Canis familiaris,Dog
D004347	Drug Interactions	The action of a drug that may affect the activity, metabolism, or toxicity of another drug.	Drug Interaction,Interaction, Drug,Interactions, Drug
D006221	Halothane	A nonflammable, halogenated, hydrocarbon anesthetic that provides relatively rapid induction with little or no excitement. Analgesia may not be adequate. NITROUS OXIDE is often given concomitantly. Because halothane may not produce sufficient muscle relaxation, supplemental neuromuscular blocking agents may be required. (From AMA Drug Evaluations Annual, 1994, p178)	1,1,1-Trifluoro-2-Chloro-2-Bromoethane,Fluothane,Ftorotan,Narcotan
D006329	Heart Conduction System	An impulse-conducting system composed of modified cardiac muscle, having the power of spontaneous rhythmicity and conduction more highly developed than the rest of the heart.	Conduction System, Heart,Conduction Systems, Heart,Heart Conduction Systems,System, Heart Conduction,Systems, Heart Conduction
D000769	Anesthesia, Inhalation	Anesthesia caused by the breathing of anesthetic gases or vapors or by insufflating anesthetic gases or vapors into the respiratory tract.	Insufflation Anesthesia,Anesthesia, Insufflation,Inhalation Anesthesia
D000771	Anesthesia, Intravenous	Process of administering an anesthetic through injection directly into the bloodstream.	Anesthesias, Intravenous,Intravenous Anesthesia,Intravenous Anesthesias
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia