Hyperkalemia & Heart Disease
Potassium is involved in the normal function of nerve and muscle cells, including the heart. Most potassium in the body - 98% - is found within cells (i.e. intracellular). When extracellular potassium levels become too high a condition known as hyperkalemia develops.
What is Hyperkalemia?
Hyperkalemia is a condition where serum potassium levels are greater than 5.5 mEq/L.
How is Hyperkalemia linked to Heart Disease?
High blood potassium levels result in arrhythmia (i.e. irregular heart beats) and may cause slowed heart beats. If hyperkalemia goes untreated it can be fatal as the heart will stop beating (i.e. cardia arrest).
What are Causes of Hyperkalemia?
When kidneys function normally potassium in the diet is typically not a concern. However, if you have poor kidney function potassium may build up in the body and lead to hyperkalemia.
Some potential causes of hyperkalemia include:
Potassium sparing diuretics (e.g. Aldactone, Bactrim)
Adrenal cortical insufficiency
Excessive parenteral potassium administration
Renal failure with low urine output (hyperkalemia typically does not occur if urine output is at least 1000 ml/day)
Medication (e.g. ACE Inhibitors)
Tissue damage (e.g. burns, trauma)
Hyperkalemic periodic paralysis
Many times food is not the primary source of potassium for individuals dealing with hyperkalemia. More often potassium accumulates due to conditions such as hemorrhage, acidosis, catabolic stress, or blood transfusions. Also, potassium sparing diuretics and salt substitutes containing potassium can contribute.
Also, sodium levels impact potassium excretion. If sodium levels are low potassium excretion may be reduced compounding hyperkalemia issues.
What are Symptoms of Hyperkalemia?
Hyperkalemia usually does not have symptoms. However, some individuals with hyperkalemia have reported nausea, fatigue, weakness, tingling, slow heart beat or faint pulse.
How is Hyperkalemia Treated?
There are several different approaches to treat hyperkalemia. Here are a few options:
- Ion exchange resins may be used to reduce intestinal absorption of potassium.
- Insulin may also be administered to decrease release of cellular potassium.
- This treatment may be combined with a low potassium diet. Dietary potassium restriction depends on serum potassium levels. A potassium restriction of 2000 to 2800 mg may be prescribed; however, levels may even be restricted down to 1000 to 1500 mg. As an FYI, the recommended potassium intake for healthy adults is 4,700 mg each day.
- Adjust or discontinue medications that are potassium sparing.
- Use potassium depleting diuretics to increase urine production.
- Administer sodium bicarbonate to counteract acidosis and move extracellular potassium back into cells.
Throughout the treatment of hyperkalemia itself, you and your physician should identify the cause of the hyperkalemia and treat the cause appropriately.