ECG library
Marked sinus arrhythmia
introA 19-year-old medical student practising on their own tracing.
25 mm/s · 10 mm/mV · synthetic tracing
100%
Calipers:2000 ms50.0 small boxes30 bpm if R-RDrag the orange markers. One small box = 40 ms.
Key findings
- Irregular RR with preserved P-before-every-QRS
- PR interval constant
Learning points
- Irregular does not mean fibrillation: the P waves are the tiebreaker.
- Phasic variation with breathing is vagal tone at work, most prominent in the young.
Connected