Potassium and Congestive Heart Failure

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The balance of potassium is important in muscle and nerve activity. With heart failure, patients tend to retain fluid and will require medications to help excrete excess fluid. But when too much fluid is lost, potassium is also lost. Monitoring the balance between fluid retention and potassium loss is critical for heart failure patients.


Heart failure is a condition in which the heart is unable to sufficiently move blood forward from either the right side of the heart to the lungs or the left side of the heart to the systemic circulation and brain. Heart failure will result from any condition that interferes with the volume of blood exiting the heart.


According to "Fluids and Electrolytes Demystified," heart failure can be classified as left-sided or right-sided. With left-sided heart failure, there is a back-up of blood into the left atria and pulmonary veins. The backup will lead to pulmonary edema, which is excess fluid in the lungs. Right-sided heart failure causes a back-up of blood into the right atrium and venous circulation, resulting in systemic edema, which causes swelling in soft tissues, often seen in the extremities.

Potassium's Role

Potassium plays a major role in the electrical stimulation of cells such as nerve and muscle cells. Adequate amounts of potassium are generally consumed through daily ingestion of foods and drinks. According to the American Heart Association, potassium controls electrical impulses of the heart that keep it beating strong. The National Institute of Health explains that when the heart muscle is not able to pump blood effectively, congestive heart failure begins.


Many patients with heart failure are treated with medications, called diuretics, to help increase the amount of urine produced to prevent fluid buildup. When urine output is increased, potassium is lost. Potassium is excreted through the kidneys, bowels and sweat, the majority being lost through the kidneys. If too much potassium is lost and not replaced, it can lead to additional complications for the patient. Because potassium is needed to control muscle action, low potassium, called hypokalemia, can cause the heart to stop beating.


The treatment goal for patients with heart failure is to decrease the workload on the heart. In the journal "Practice Nursing," the recommended treatment for heart failure consists of supplemental oxygen, diuretics and dietary restrictions. Patients may be placed on fluid restrictions and instructed to reduce their salt intake. Patients will need to have blood tests checked occasionally to monitor their potassium level. If the potassium level is low, potassium supplements may be necessary to bring the level back to normal and prevent further complications.