how hypokalemia causes arrythmias?

Question

please explain its effect on action potential

Answer 1

Hypokalemia means low serum potassium (low blood levels of potassium). It may result from a number of conditions.
Small changes in the potassium concentration outside cells can have substantial effects on the activity of nerves and muscles. This is particularly true of heart muscle. Low levels of potassium cause increased activity (which can lead to an irregular heartbeat), whereas high levels cause decreased activity. Either situation can lead to cardiac arrest in some circumstances.
A shortage of potassium in body fluids may cause a potentially fatal condition known as hypokalemia (see article for detail), typically resulting from diarrhea, increased diuresis and vomiting. Deficiency symptoms include muscle weakness, paralytic ileus, ECG abnormalities, decreased reflex response and (in severe cases) respiratory paralysis, alkalosis and arrhythmia.
For heart patients, it is highly necessary to reduce sodium intake and to increase potassium in the diet. Eating a variety of foods that contain potassium is the best way to get an adequate amount. Healthy individuals who eat a balanced diet rarely need supplements. Foods with high sources of potassium include orange juice, potatoes, bananas, avocados, apricots, parsnips and turnips, although many other fruits, vegetables, and meats contain potassium. Research has indicated that diets high in potassium can reduce the risk of hypertension.
Please see the webpage for more details on Potassium and Potassium test.

Answer 2

The pumping mechanism of the heart works on what is known as the potassium-sodium pump. What happens is that potassium is on one side of the cell and sodium is on the other. When they switch places back and forth, an electric current is set up that fires the heart. If there is too little or too much potassium, then the heart will not fire correctly, which can lead to serious cardiac problem and even death if not corrected. This is the simplest way to explain it. If this is for a science or medical field class, the principle is based on proton exchange. Both sodium and potassium are positively charged and will be on opposite sides of the cell membrane. When one crosses the membrane to one side, the other proton must cross in exhange. This is called a proton-pump. This action is what sets up the electrical current. An imbalance in either electrolyte will adversely affect the action potential by increasing or decreasing it significantly and dangerously. One place you can look to get more info is go to the Heart Association and look up their protocols for ACLS. There should be a listing of signs and symptoms for hypokalemia in their interventions.