Objective: To observe the maximal heart rate changes, atrioventricular (A-V) conduction block and atrial fibrillation (AF) inducibility in dogs with vagosympathetic trunk exposed to electromagnetic fields (EMFs).
Methods: The vagosympathetic trunk of adult dogs was separated and exposed to EMFs 0.043 kHz (2.87 microG, n = 5) and to EMFs 2 kHz (0.34 microG, n = 6) for two to three hours. Simultaneously, the vagosympathetic trunk was stimulated with 20 Hz frequency and 1 - 8 V intensity for 0.1 ms. Heart rate, presence of A-V conduction block and AF inducibility were determined.
Results: After 5-minutes exposure to EMFs 0.043 kHz (2.87 microG), the maximal heart rate decreased 29%, the voltage applied to vagosympathetic trunk required to induce A-V conduction block decreased by 60% in experimental group versus 5% increase in control group. This effect lasted 2 to 3 hours. While vagosympathetic trunk exposure to EMFs 2 kHz (0.34 microG) was associated with significant increase in the incidence of atrial premature beats, atrial tachycardia and AF, these effects could be blocked by propranolol and atropine.
Conclusions: Our results showed that 0.043 kHz (2.87 microG) EMFs exposure might reduce while 2 kHz (0.34 microG) EMFs exposure might increase AF inducibility. Our study thus suggested autonomic nervous system of dogs could be affected by EMFs exposure and 0.043 kHz (2.87 microG) EMFs exposure might be a novel option for AF prevention.
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Feeding of managed populations of giant anteater () is challenging in injured patients that present with anorexia. This report describes an approach for esophagostomy tube placement in this species. Cadavers of two adult giant anteaters were used for technique development.
View Article and Find Full Text PDFJ Am Anim Hosp Assoc
March 2024
From Willows Veterinary Centre and Referral Service Ltd, West Midlands, England.
A 3 yr old female spayed Labrador retriever was referred for the treatment of a chronic oropharyngeal stick injury. After computed tomography scan evaluation, the cervical area was explored surgically and a right-sided cervical abscess that contained a wooden stick was identified adjacent to the vagosympathetic trunk and carotid artery. The ipsilateral mandibular salivary gland was resected concurrently given its abnormal appearance, and histology confirmed inflammation and necrosis of the gland, which was suspected to be due to direct trauma from the foreign body.
View Article and Find Full Text PDFPol J Vet Sci
December 2022
Department of Animal Anatomy, Faculty of Veterinary Medicine, University of Warmia and Mazury, Oczapowskiego 13, 10-719 Olsztyn, Poland.
The present study investigated the distribution and chemical properties of nerve cell bodies within the trunk of the vagus nerve in juvenile female pigs (n=4) using double-labelling immunofluorescence. The neurons appeared mostly as single cells or formed streaks of cells or small ganglia. Many of the perikarya were cholinergic (VAChT-positive; VAChT+) or adrenergic (DβH+) in nature and no SP+ or CGRP+ neurons were encountered.
View Article and Find Full Text PDFAnn Anat
June 2022
Division of Anatomy and Embryology, Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Background: No reports have been made on the entire extrinsic innervation of the heart in small laboratory animals. Therefore, this study examined the detailed morphotopographic features of the extrinsic cardiac autonomic nervous system (ECANS) with its adjacent structures (1) to record the general morpho-topography and variations of the ECANS in guinea pigs, (2) to compare it with previous reports on common laboratory rodents (rats, mice, and Syrian hamsters), rabbits, domesticated animals (cats, dogs, sheep, goats, oxen, pigs, and horses), primates, and humans, and (3) to infer the macroscopic evolutionary changes they presented.
Methods: The sympathetic ganglia, vagi, and emitting cardiac nerves/branches in the cervical and thoracic regions were dissected in 24 sides of 12 formalin-fixed, arterially injected adult male and female guinea pigs under a stereomicroscope.
Heart Rhythm
June 2022
University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine, UCLA, Los Angeles, California; UCLA Molecular, Cellular & Integrative Physiology Program, UCLA, Los Angeles, California. Electronic address:
Background: Mapping the structure/function organization of the cardiac nervous system is foundational for implementation of targeted neuromodulation-based therapeutics for the treatment of cardiac disease.
Objective: The purpose of this study was to define the spatial organization of intrathoracic parasympathetic and sympathetic efferent projections to the heart.
Methods: Yucatan mini-pigs (N = 11) were anesthetized and the thoracic cavity exposed.
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