Interaction of brain and intracardiac levels of rhythmogenesis hierarchical system at heart rhythm formation. Journal of Integrative Neuroscience, Vol. 7, No. 4 (2008) 457- 462.
...read...Medical Hypotheses Volume 66, Issue 1 , 2006, Pages 158-164
Hierarchy of the heart rhythmogenesis levels is a factor in increasing the reliability of cardiac activity
Vladimir M Pokrovskii
Kuban State Medical University, Department of Normal Physiology, Sedin Street, 4, Krasnodar 350063, Russia Received 3 June 2005; accepted 27 June 2005 Summary Along with the existence of an intracardiac pacemaker a generator of cardiac rhythm exists in the central nervous system - in the efferent structures of the cardiovascular center of the medullar oblongata. Neural signals originating there in the form of bursts of impulses conduct to the heart along the vagus nerves and after interaction with cardiac pacemaker structures cause generation of the cardiac pulse in exact accordance with the frequency of the neural bursts. That the intrinsic cardiac rhythm generator is a life-sustaining factor that maintains the heart pumping function when the central nervous system is in a stage of deep inhibition. The brain generator is the factor that provides the heart with adaptive reactions to changes in the environment. The hierarchy of the two duplicating levels of rhythmogenesis provides reliability and functional perfection of the cardiac rhythm generation system in the whole organism. ...read...Journal of Integrative Neuroscience, Vol. 4. No. 2 (2005) 161-168
Integration of the heart rhythmogenesis levels: heart rhythm generator in the brain
Vladimir M. Pokrovskii, MD, PhD
Normal Physiology Department, Kuban State Medical Academy, Krasnodar, Russia
Received 26 October 2004
Accepted 18 February 2005
We propose that along with the intracardiac pacemaker, a generator of cardiac rhythm exists in the central nervous system - in the efferent structures of the cardiovascular center of the medullar oblongata. Signals in the medulla oblongata arise as a result of the hierarchic interaction of the brain structures. Neural signals originating there in the form of bursts of impulses conduct to the heart along the vagus nerves and after interaction with cardiac pacemaker structures, cause generation of the cardiac pulse in exact accordance with the frequency of "neural bursts". The intrinsic cardiac rhythm generator (the sinus node) is a life-sustaining factor that maintains the heart pumping function when the central nervous system is in a stage of deep inhibition, (e.g., under anesthesia or during unconsciousness). The brain generator is the factor that provides heart adaptive reactions in behaving organism. The integration of the two levels of rhythmogenesis in the brain and heart provides reliability and functional perfection of the cardiac rhythm generation system in the whole organism.
Keywords: Heart rhythm; duplicated control; cardiorespiratory synchronization; heart rhythm generator in the brain.
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Heart, Lung and Circulation 2003; 12
Alternative View on the Mechanism of Cardiac Rhythmogenesis
Vladimir M. Pokrovskii, MD, PhD
Kuban State Medical Academy, Department of Normal Physiology, Krasnodar, Russia
Background: This article advances an hypothesis that there is duplication of the heart rhythmo-genesis system.Methods and Results: The following article reviews available data and advances an hypothesis to suggest new ideas about the mechanisms of cardiac rhythm generation. The hypothesis is that along with the existence of an intracardiac pacemaker, the generator of cardiac rhythm exists in the central nervous system - in the efferent structures of the cardiac centre of the medulla oblongata. Originating in the medulla oblongata, neural signals in the form of brief bursts of pulses are conducted to the heart along the vagus nerves and, by interacting with the cardiac pacemaker structures, cause generation excitement in the heart in exact accordance with the frequency of the bursts. The intracardiac rhythm generator is a life-providing factor that maintains the heart pumping function when the central nervous system is in a stage of deep inhibition (e.g. under anaesthesia or when unconscious). The central generator is the factor that provides the heart with adaptive reactions in natural conditions of the organism. Conclusions: Multi-leveled organisation of the mechanisms responsible for rhythmogenesis guarantees reliability and functional perfection of the cardiac rhythm generation system. (Heart, Lung and Circulation 2003; 12:18-24)
Key words: cardiac rhythm, generation. ...read..