Sinus node dysfunction diagnostic criteria6
| 1. Sinus bradycardia |
| • Neonates and infants: <60 beats/min asleep and <80 beats/min awake |
| • Children aged 2–6 years: <60 beats/min |
| • Children aged 7–11 years: <45 beats/min |
| • Adolescents and young adults: <40 beats/min |
| • Endurance and other highly trained athletes: <30 beats/min |
| 2. Severe sinus arrhythmia (variation in RR interval of ⩾100%) |
| 3. Sinus pause or arrest |
| 4. Escape rhythms at slow rate |
| 5. Sinoatrial exit block (second degree, type I and II) |
| 6. Bradycardia/tachyarrhythmia |