Sinus arrhythmia
An ECG at Age 19
ECG from a 19-year-old woman. The reason for recording and symptoms are not supplied.
Look for
- P waves with sinus morphology.
- One conducted P wave before each QRS.
- Varying R–R intervals.
Where to look. Follow several cycles in lead II rather than judging a single R–R interval.
The rhythm retains a sinus origin despite changing R–R intervals. Breathing can produce this pattern, but no respiratory signal is supplied here.
The source rate is 79/min; a respiratory cause is not directly demonstrated.
References & provenance
The ECG Made Easy, 9e, ch. 2, PDF 41–44; ch. 4, PDF 91–93; Lilly, 6e, ch. 4, p. 85–88.
ECG Sinus Arrhythmia 79 bpm.jpg
ECG Sinus Arrhythmia 79 bpm.jpg — Ewingdo — Wikimedia Commons — CC BY-SA 4.0 — https://commons.wikimedia.org/wiki/File:ECG_Sinus_Arrhythmia_79_bpm.jpg. Indiquer toute modification. CC BY-SA 4.0
Adaptation: cropping and removal of headers/annotations outside the tracing where applicable; metadata removed. Waveforms have not been redrawn.
Compared with the published source; no independent clinical validation is claimed.
Original annotations & limitations
Arythmie sinusale
ECG of a 19-year-old female with sinus arrhythmia. Heart rate 79 bpm. QT/QTC 356/408 ms
Âge et sexe documentés; variation respiratoire non documentée par un signal respiratoire: ne pas affirmer qu’elle est mesurée ici.