- An irregular or skipping heartbeat
- A heartbeat that races out of control without warning
- Fluttering or thumping in the chest
- Dizziness
- Shortness of breath and anxiety
- Weakness
- Faintness or confusion
- Fatigue
- Sweating
- Atrial fibrillation
- Supraventricular tachycardia
- Ventricular tachycardia
- Sick sinus syndrome
- Pacemaker or defibrillator malfunction
- Wolff-Parkinson-White syndrome