Welcome to our Sinus Arrhythmia reference page. This page provides a summary definition followed by introductions to our practice drills, quizzes, lessons and interactive guides.
Sinus Arrhythmia Definition
Sinus Arrhythmia, is a type of sinus rhythm where the P-P interval varies by greater than 10%.
This variation occurs during inspiration and expiration.
This is a normal condition and is often more noticeable in children.
Non-respiratory arrhythmias can be abnormal and are covered in other pages on this website.
Sinus Arrhythmia ECG Features
The following table summarizes the key features of an sinus arrhythmia ECG strip.
|Rhythm||Irregular, varying with respiration
|Rate||Normal (60-100 bpm) and rate may increase during inspiration
|PR Interval||Normal (0.12-0.20 sec)
|QRS||Normal (0.06-0.10 sec)
|Notes||Heart rate frequently increases with inspiration, decreasing with expiration