From Mdwiki | Sinus arrhythmia | |
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| 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]
Categories: [Vagus nerve] [Cardiac electrophysiology] [Cardiac arrhythmia]