Sinus arrhythmia

ECG of a 19-year-old female with sinus arrhythmia
Specialty| Cardiology
Diagnostic method| electrocardiogram

Sinus arrhythmia is a normal variation of sinus rhythm, noticed as an irregular heart rate; fast when taking a breath in, and slow when breathing out.[1] It is commonly observed in children and young adults.[1] When present, sinus arrhythmia typically indicates good cardiovascular health.[2]

During respiration, the intermittent vagus nerve activation occurs, which results in beat to beat variations in the resting heart rate.[2] Sinus arrhythmia characteristically presents with an irregular rate in which the variation in the R-R interval is greater than 0.12 seconds.[2] Additionally, P waves are typically mono-form and in a pattern consistent with atrial activation originating from the sinus node.[2]

## See also[edit | edit source]

* Vagal tone

## References[edit | edit source]

1. ↑ 1.0 1.1 Bunce, Nicholas H.; Ray, Robin; Patel, Hitesh (2020). "30. Cardiology". In Feather, Adam; Randall, David; Waterhouse, Mona (eds.). Kumar and Clark's Clinical Medicine (10th ed.). Elsevier. p. 1051\. ISBN 978-0-7020-7870-5. Archived from the original on 2022-02-12. Retrieved 2022-02-11.
2. ↑ 2.0 2.1 2.2 2.3 Soos, Michael P.; McComb, David (2020-08-24). "Sinus Arrhythmia". NCBI Bookshelf. PMID 30725696. Archived from the original on 2020-11-01. Retrieved 17 November 2020. Text was copied from this source, which is available under a Creative Commons Attribution 4.0 International License Archived 2017-10-16 at the Wayback Machine.