Sodium and Heart Palpitations

Sodium is essential to life and the normal functioning of the body. Present in the blood and bodily fluids, salt has important functions in several organs, including the brain and heart.

Functions

• Sodium is vital for proper blood pressure and blood volume regulation. Additional important roles include normal nerve and muscle function (including heart muscle), water absorption, and the absorption of blood sugar, amino acids and chloride.

Normal Values

• According to eMedicine, normal blood sodium levels range from 135 to 145 mEq/L (milli-equivalents per liter). Excess blood sodium is referred to as hypernatremia, while the term "hyponatremia" describes abnormally low body sodium.

Palpitations Definition

• According to Medicine Net, palpitations are irregular and/or pounding heartbeats. Arrhythmias (abnormal heart rhythms) may result in palpitations, whether heartbeats are too slow, too fast or too early. The resting adult heart normally beats at a rate of 60 to 100 beats per minute (bpm), although a heart rate lower than 50 bpm may be normal for athletes.

Effects of Excess Sodium

• Medscape defines hypernatremia as a blood sodium level exceeding 145 mEq/L. The various effects of hypernatremia include a rapid heart rate (tachycardia), which can translate into palpitations.

Effects of Low Sodium

• Medscape defines hyponatremia as a drop in blood sodium levels to a value lower than 135 mEq/L. Hyponatremia is considered severe when blood sodium levels fall below 125 mEq/L. Low blood sodium initially results in heart rate acceleration, but advanced signs include bradycardia (slow heart rate).

Considerations

• According to the Merck Manual of Medical Information, the nervous system is highly sensitive to changes in blood sodium levels. As a result, disturbances in sodium levels typically lead to brain dysfunction before causing heart rate abnormalities and other symptoms.