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LEFT ATRIAL RECEPTOR INHIBITION OF CARDIAC EFFERENT VAGAL ACTIVITY IN THE DOG
Author(s) -
Chapman L. W.,
Mittman U.,
Prickett C.,
Richmond W.
Publication year - 1978
Publication title -
clinical and experimental pharmacology and physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 103
eISSN - 1440-1681
pISSN - 0305-1870
DOI - 10.1111/j.1440-1681.1978.tb00699.x
Subject(s) - efferent , propranolol , medicine , vagus nerve , tachycardia , heart rate , cardiology , atrial tachycardia , endocrinology , stimulation , anesthesia , afferent , blood pressure , atrial fibrillation , catheter ablation
SUMMARY 1. The tachycardia produced by atrial receptor stimulation has been reported to be ‘solely’ due to an increased sympathetic activity, but not inhibitable by propranolol. We examined the effect of left atrial balloon inflation in chloralose‐anaesthetized dogs on heart rate with and without propranolol (l. Omg/kg) and on the activity in single cardiac efferent fibres of the vagus nerve. 2. Propranolol reduced the cardiac response to balloon inflation by one‐third, but did not abolish the tachycardia. Efferent cardiac vagal activity was 3.8 ± 0.4 spikes/s and 2.3 ± 0.7 spikes/s prior to and during balloon inflation respectively. 3. It was concluded that the left atrial receptors produce a tachycardia by decreasing cardiac parasympathetic and increasing sympathetic efferent activities.