If your heart is racing all the time does that make you lose calories?

Usually no. The cause of a racing heart will dictate whether calories are being lost. In some patients with hyperthyroidism, the heart rate will be increased because of the endocrine problem and hyperthyroidism does speed up general metabolism and thus you will burn more calories. If your heart rate is elevated because of an abnormal heart rhythm such as afib or because of stress - there would be no loss.