Determine the following:
Rhythm: _______________________________________
Rate: _______________________________________
P waves: _______________________________________
PR interval: _______________________________________
QRS complex: _______________________________________
What's your interpretation?
(Answers on next page)
Name that strip: Answers
Rhythm: Irregular
Rate: 60 beats/minute
P waves: Sinus
PR interval: 0.16 to 0.20 second
QRS complex: 0.06 to 0.08 second
Comment: ST segment depression is present
Interpretation: Sinus arrhythmia
Sinus arrhythmia is a normal physiologic phenomenon most common in children and young adults. It is caused by the changes in vagal tone that occur during the respiratory cycle. The heart rate gradually slows down with expiration and then gradually speeds up with inspiration. Sinus arrhythmia is of no clinical significance and does not require treatment unless it is associated with symptomatic bradycardia.
Sinus arrhythmia: Identifying ECG features
Rhythm: Irregular
Rate: Normal (60 to 100 beats/minute) or slow (less than 60 beats/minute)
P waves: Normal in size, shape, and direction; positive in lead II; one P wave precedes each QRS complex
PR interval: Normal (0.12 to 0.20 second)
QRS complex: Normal (0.10 second or less)