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Determine the following:

  
Figure. No caption a... - Click to enlarge in new windowFigure. No caption available.

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)