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.

Kaplan–Maier estimate of 12‐month freedom from a ≥30‐second recurrence of atrial fibrillation (AF)/atrial flutter (AFL)/atrial tachycardia (AT) in patients with paroxysmal AF (blue) and persistent AF ...