Understanding of effects of potassium on cardiac tissue by medical students: a critical appraisal

Raj Kumar Arya, Parag Sharma, Dinesh Kumar Jain

Abstract


Potassium (K+) is one of the most important ion present in the human body and involved in numerous physiological activities. It mainly affects heart and skeletal muscle but the effects are not confined to theses organs only. The article precisely focuses on the explaining the physiological as well as pathological aspects of potassium on cardiac tissue. This article tends to explain: The cause of difference in extra cellular and Intra cellular concentration of potassium when potassium channels are open in resting conditions, why are Purkinje fibers and ectopic tissue are more sensitive to effect of potassium, mechanisms responsible for increased action potential duration by hypokalemia and decreased action potential duration by hyperkalemia. Hypokalemia generates ectopic activities and hyperkalemia inhibits them, therapeutic effects of potassium administration without causing hyperkalemia. These issues will be discussed and try to be explained with the help of Ohm’s law , Nernst equation and Nernst potential to sort out the complicated actions of potassium on cardiac tissue in a simplified manner. The primary aim of article is to improve understanding of potassium physiology by medical graduates, secondarily, convey message regarding improvement in teaching methodology in Pharmacology for the benefit of new generations.


Keywords


Hypokalemia, Hyperkalemia, Nernst equation, Membrane resting potential

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References


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