Excess Potassium & Heart Rate

Potassium is an important positively charged electrolyte found within cells. At a normal concentration, it allows the adequate functioning of the heart muscle by maintaining a regular heart rate and rhythm. Potassium is obtained in the diet; adequate intake is necessary to prevent a decrease in blood potassium and subsequent disruption of heart functions. High blood potassium may result in increased heart rate.

Sources of Potassium

Major sources of potassium are found in vegetables and fruits, such as oranges, bananas, raisins, strawberries, apricot and prunes. Potassium is found in a variety of dairy products including milk and cheese. Other sources of potassium include meat, fish, avocados, potatoes, beans and peas.

Potassium Regulation

Potassium must be regulated tightly because even small changes in the blood may result in changes in heart function. Potassium is constantly excreted by the kidneys and to maintain normal blood potassium levels, potassium must be replenished by proper dieting. Aldosterone -- a steroid hormone produced by the adrenal glands -- is released when potassium concentration is higher than normal. Aldosterone increases the excretion of potassium from the kidneys; it also increases sodium reabsorption in the kidneys, which directly impacts the blood pressure.

The Heart Rate

The rate at which the heart contracts, is a reflection of current energy and oxygen needs. The heart is responsible for pumping oxygen-rich blood to the rest of the body. When more oxygen is needed, the heart rate increases to meet oxygen demands; the faster the heart rate, the greater the amount of oxygen delivered to the tissues. Increasing the heart rate is usually beneficial but a too rapid heart rate, compromises the time needed for the heart to fill up with blood and is therefore counterproductive.

Excess Potassium and Heart Failure

Increased potassium levels in the blood usually does not result from dietary intake in a person with a normal kidney function, but is likely in people with abnormal kidney function, which results in the accumulation of potassium in the blood. Excess blood potassium may result from electrolyte imbalance which predisposes a person to abnormal heart rhythms. According to "Principles of Orthomolecularism," excess potassium results in magnesium depletion which causes acceleration of the heart rate; however, excess magnesium results in potassium depletion which causes irregular heart rhythms. A regular heart rhythm is necessary for adequate pumping of blood and without it, the heart fails.