Propagation of Impulses across the Purkinje Fiber-Muscle Junctions in the Dog Heart
- 1 February 1970
- journal article
- research article
- Published by Wolters Kluwer Health in Circulation Research
- Vol. 26 (2), 135-150
- https://doi.org/10.1161/01.res.26.2.135
Abstract
In canine Purkinje fiber-papillary muscle preparations it was shown directly that electrotonic spread can take place across the junctions between Purkinje fibers and ordinary muscle fibers (P-M junctions). The P-M delay recorded during orthodromic propagation varied considerably within any given preparation. Moderate increases in the external concentration of K+ (up to 6 mM) consistently decreased the P-M delay; when the concentration of external K+ was increased to 8 mM the P-M delay increased. With larger concentrations of K+ (10 to 11 mM), total conduction block from the terminal Purkinje fibers to the muscle occurred; under the same conditions antidromic propagation from muscle to Purkinje fiber was still possible. The results can be explained satisfactorily by assuming that propagation across the P-M junction is electrical and that the geometry of the functional syncytium changes progressively from a cable-like system at the level of the terminal Purkinje fibers to a two- or three-dimensional irregular syncytium at the bulk of the myocardial mass.Keywords
This publication has 8 references indexed in Scilit:
- Membrane ionic conductances during rest and activity in guinea pig atrial muscleAmerican Journal of Physiology-Legacy Content, 1967
- The diffusion of radiopotassium across intercalated disks of mammalian cardiac muscleThe Journal of Physiology, 1966
- Electrotonic Interaction between Muscle Fibers in the Rabbit VentricleThe Journal of general physiology, 1966
- Propagation of Action Potentials and the Structure of the Nexus in Cardiac MuscleThe Journal of general physiology, 1965
- A COMPARISON OF THE CONDUCTION VELOCITY IN CARDIAC TISSUES OF VARIOUS MAMMALSQuarterly Journal of Experimental Physiology and Cognate Medical Sciences, 1959
- Refractoriness in Cardiac MuscleAmerican Journal of Physiology-Legacy Content, 1957
- CHANGES IN MEMBRANE CHARACTERISTICS OF HEART MUSCLE DURING INHIBITIONThe Journal of general physiology, 1956
- The electrical constants of Purkinje fibresThe Journal of Physiology, 1952