Why Does Hyperkalaemia Cause Cardiac Arrest?
Inputs by Dr. Sanjeevkumar Kalkekar, Consultant, Cardiology, at Apollo Hospitals, Navi Mumbai.
Hyperkalaemia arises when the concentration of potassium in the bloodstream goes above a certain limit, throwing the body’s internal pH balance out of the normal functioning. The chief causes of Hyperkalaemia are potassium sifting out of cells into the blood circulation, diseases of the adrenal gland, kidney dysfunction and medications.
One of the reasons why your internal pH balance is so essential is that many of the cells depend on a negative voltage gradient across their cell membranes to function as usual. That negative gradient is what makes it possible for the cell to respond to the hormones and other chemical messengers that tell it what to do. One of the ways cells maintain that pitch, is by adjusting the amount of potassium, a positively charged ion, inside the membrane in opposition to outside.
If the potassium levels in the bloodstream get too high, the condition known as Hyperkalaemia, it hyperpolarizes the membrane, which changes the amount and type of signalling that activates cell activity. Any cells that rely on this signalling, such as the nerves, the heart, and muscle cells, start to go out of order and may cause Cardiac Arrest. Occasionally, when severe, it results in numbness, palpitations, muscle weakness, or muscle pain.
Different muscles in your heart may start contracting at different times; a condition called Arrhythmia.