Aug 1, 1975

Roles of the AV junction in determining the ventricular response to atrial fibrillation

Canadian Journal of Physiology and Pharmacology
J BilletteR A Nadeau


The statistical properties of RR interval sequences during cholinergic atrial fibrillation were studied in anesthetized dogs both in control conditions and after the selective injection of dromotropic agents into the atrioventricular (AV) node artery. It was observed that RR interval histogram configurations depended mainly on the mean heart rate, regardless of whether it was a control or a post-injection sequence. The sequences were found to vary from almost regular at fast rates to highly irregular at slow rates, covering all intermediate possibilities. Since the injections of dromotropic agents into the AV node artery were carried out during sinus rhythm between the episodes of fibrillation, their influences on the AV junction, as reflected both on the length of the PR interval during sinus rhythm and on the RR interval dispersion during fibrillation, could be compared. The dispersion of RR intervals was found to increase as the PR interval duration became longer. In addition, it was observed that the generally random character of the RR interval sequences during fibrillation was not affected by the injection of dromotropic agents into the AV node artery. These results were interpreted as an indication that, for a well-estab...Continue Reading

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Mentioned in this Paper

Arterial System
Left Ventricular Structure
Sinus - General Anatomical Term
Atrial Fibrillation
Cardiac Conduction System
Structure of Atrioventricular Node

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