Hyperkalemia: ECG manifestations and clinical considerations.

Hyperkalemia is a common cause of electrolyte induced cardiac conduction disturbance. A well-defined series of changes at the cellular level leads to characteristic evolutionary changes in the surface electrocardiogram. Initial high T waves and shortened intervals give way to prolongation of conduction and lethal dysrhythmias as the serum potassium level rises. The patterns of electrocardiographic changes associated with hyperkalemia are reviewed and an outline of appropriate therapeutic interventions.