Cardiac Electrophysiology: The Sinoatrial Node in Focus
Nzerem Francis Egenti,
Ugorji Hycinth Chimezie
Issue:
Volume 4, Issue 4, December 2018
Pages:
59-66
Received:
27 September 2018
Accepted:
19 November 2018
Published:
3 January 2019
DOI:
10.11648/j.ml.20180404.11
Downloads:
Views:
Abstract: The integrity of the cardiac cells and muscles is essential for quality of life. The sinoatrial node cells are the definitive cells of cardiac electrophysiology. They are the primary source of action potentials. Lamentably, the question of ion currents that generate the much needed cardiac action potentials is yet to be resolved. The nagging issue of the presence or otherwise of the sodium ion (Na+) in the sino-atrial node cells may cast doubts at the propriety of clinical measures that target some cardiac events. Some literatures suggest the presence of the said ion at the periphery of the sino-atrial node while contending that it is totally absent in the node centre. Other literatures hold that it is present the entire sino-atrial node. In the light of these, this paper proposed a refined model equation of the cardiac sino-atrial node membrane current. The node centre, known to be the origin of cardiac action potential, was given a bit closer look. Physiological delay arising from the flow of a class of calcium ion current (L-Type calcium current), the bastion of the sino-atrial node centre action potential, was also considered. Ostensibly, the timing of specific ion currents during action potentials may furnish some clues on cardiac conditions.
Abstract: The integrity of the cardiac cells and muscles is essential for quality of life. The sinoatrial node cells are the definitive cells of cardiac electrophysiology. They are the primary source of action potentials. Lamentably, the question of ion currents that generate the much needed cardiac action potentials is yet to be resolved. The nagging issue ...
Show More
Global Stability Analysis of the SEIR Deterministic Model in the Presence of Treatment at the Latent Period
Issue:
Volume 4, Issue 4, December 2018
Pages:
67-73
Received:
5 November 2018
Accepted:
19 November 2018
Published:
3 January 2019
DOI:
10.11648/j.ml.20180404.12
Downloads:
Views:
Abstract: In this paper, the objective was to find out the influence of introducing treatment at the latent period of disease (infectious) transmission as a result the global dynamics of the SEIR epidemic model with the introduction of treatment at the latent period is explored. The basic reproduction number is estimated. Whenever the basic reproduction number is not larger than unity (R0≤1) then the disease – free equilibrium is globally stable and the disease dies out. But when the basic reproduction number is larger than unity (R0>1), then there exist the endemic equilibrium point which is stable and hence the disease will persist. This was demonstrated with a tuberculosis data obtained from Amansie west district health directorate in the Ashanti region of Ghana.In this instance the endemic equilibrium point was found to be stable. The sensitivity analysis also revealed that increasing the treatment rate introduced at the latent period will reduce the value of the basic reproduction number.
Abstract: In this paper, the objective was to find out the influence of introducing treatment at the latent period of disease (infectious) transmission as a result the global dynamics of the SEIR epidemic model with the introduction of treatment at the latent period is explored. The basic reproduction number is estimated. Whenever the basic reproduction numb...
Show More
