Sodium and potassium ions are essential for muscle contractions of the heart. the ions are transported using a pump, which obtains energy by the breaking of adp or atp or calcium

Pumps generally push ions from a low concentration to a high concentration. Because it is going against something that is thermodynamically unfavorable, the pumps require ATP to function. The pumps essentially push the ions upstream to a higher gradient and it will require the energy stored in ATP to do it.