Most causes for waking up with a racing heart aren't serious. But some may require treatment. Learn the causes of heart palpitations and when to see a doctor.

Add steroid pulse therapy (0.5–1.0 g methylprednisolone for 3 consecutive days) Add IVIG (400 mg/kg/day for 5 consecutive days) Add mizoribine (150 mg/day once after breakfast) ...