Will Hyperkalemia Cause Bradycardia?

Isolated hyperkalemia may precipitate bradycardia, which, in turn, leads to renal failure. However, hyperkalemia does not generally cause bradycardia until the degree of hyper- kalemia is severe (e.g., potassium over 7 mEq/L) (1,10).

Does hyperkalemia cause tachycardia or bradycardia?

Cardiac arrythmias associated with hyperkalemia include sinus bradycardia, sinus arrest, slow idioventricular rhythm, ventricular tachycardia, ventricular fibrillation and asystole. The usual clinical scenario is of hyperkalemia presenting as bradycardia.

Why does hyperkalemia cause decreased heart rate?

The change in serum postassium affects the repolarisation part of the action potential (labelled '3' in the diagram below). Hyperkalaemia leads to a flattening of the angle of this part of the action potential which can lead to a slower heart rate.