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The response to distension of the pulmonary vein—left atrial junctions in dogs with spinal section
Author(s) -
Burkhart Sally M.,
Ledsome J. R.
Publication year - 1974
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1974.sp010504
Subject(s) - distension , pulmonary vein , section (typography) , medicine , cardiology , anatomy , atrial fibrillation , business , advertising
1. A reflex increase in heart rate in response to pulmonary vein distension was observed in decerebrate dogs. This increase could not be totally abolished by treatment with both propranolol and bretylium tosylate. Only bilateral cervical vagotomy abolished the reflex increase in heart rate. 2. A significant increase in heart rate occurred in a total of seventeen spinal dogs during pulmonary vein distension. 3. In seven spinal animals in which blood pressure was maintained by the continuous infusion of noradrenaline, the increase in heart rate could be totally prevented by cervical vagotomy. 4. The time course of the increase in heart rate observed in the spinal animals was rapid, reaching maximum expression within 10 sec of pulmonary vein distension. Such a time course is dissimilar from that associated with pulmonary vein distension in intact or decerebrate dogs in which maximum increases in heart rate take 1–3 min to develop. 5. It is concluded that the reflex tachycardia resulting from pulmonary vein distension may be mediated by both an efferent sympathetic and an efferent vagal pathway, the relative significance of each component being dependent upon the prevailing autonomic drive existent in the animal at any specific time.