Sinus Rhythm
Normal heart rhythm originating from the sinoatrial node
Definition
Sinus rhythm (normal sinus rhythm, NSR) is the heart's normal electrical rhythm, originating from the sinoatrial (SA) node at a rate of 60 to 100 bpm.
ECG Features of NSR
- Rate: 60 to 100 bpm
- Regular rhythm
- P wave before every QRS
- Normal PR interval (0.12 to 0.20 sec)
- Normal QRS duration (less than 0.12 sec)
- Normal QT interval
Related Rhythms
- Sinus bradycardia: NSR with rate less than 60
- Sinus tachycardia: NSR with rate greater than 100
- Sinus arrhythmia: Normal variation with respiration (common in young)
Nursing Considerations
Continuous telemetry monitoring for patients at risk for arrhythmias. Correlate rhythm with clinical status. Correct reversible causes of sinus tachycardia (pain, fever, dehydration, anxiety).
NCLEX Relevance
Identify NSR as baseline before diagnosing arrhythmias.