From the Research
No, hypernatremia typically does not cause bradycardia, and is more likely to cause tachycardia due to increased cardiac contractility and heart rate. Hypernatremia, which is an elevated sodium level in the blood (typically above 145 mEq/L), usually leads to increased cardiac contractility and heart rate. This occurs because:
- The higher sodium concentration creates an osmotic gradient, pulling fluid out of cells, including cardiac cells.
- This cellular dehydration triggers the release of stress hormones like epinephrine and norepinephrine.
- These hormones stimulate the heart, increasing both heart rate and contractility. Common symptoms of hypernatremia include thirst, confusion, muscle twitching, and in severe cases, seizures or coma. The primary treatment for hypernatremia is careful rehydration to slowly correct the sodium imbalance, typically using hypotonic fluids, as recommended by recent studies 1. It's crucial to correct sodium levels gradually to avoid complications like cerebral edema, with a recommended correction rate not exceeding 8-10 mmol/l/day for preexisting hypernatremia 2 or 12 mEq/liter/day 3. If a patient with hypernatremia presents with bradycardia, it's essential to investigate other potential causes, as the bradycardia is likely unrelated to the hypernatremia itself. In extreme cases of hypernatremia, such as the one reported in 4, fatal arrhythmias can occur, highlighting the importance of careful management and monitoring.