When caring for a patient with a cardiac dysrhythmia, which laboratory value is a priority for the healthcare provider to monitor?

Because abnormalities in sodium, potassium and calcium levels are likely to affect depolarization and repolarization of cardiac cells, it is most important for the healthcare provider to monitor these laboratory values. BUN and creatinine levels are always important to monitor when giving any drug, not only anti-dysrhythmia drugs. The PT and INR will be important for patients who are on warfarin (Coumadin).