Determine the following:
Rhythm: _______________________________________
Rate: ___________________________________________
P waves: _______________________________________
PR interval: ____________________________________
QRS complex: __________________________________
What's your interpretation?
(Answers on next page)
Name that strip: Answers
Rhythm: Regular
Rate: 84 beats/minute
P waves: Hidden in QRS complex
PR interval: Not measurable
QRS complex: 0.06 to 0.08 second
Interpretation: Accelerated junctional rhythm.
Accelerated junctional rhythm is a dysrhythmia originating in the atrioventricular (AV) junction with a rate between 60 and 100 beats/minute. The term "accelerated" denotes a rhythm that exceeds the junctional escape rate of 40 to 60 beats/minute but is not fast enough to be junctional tachycardia.
The P waves are inverted in lead II (a positive lead) and will occur immediately before or after or will be hidden within the QRS complex. The PR interval is short (0.10 second or less) if present. The QRS duration is usually normal. Accelerated junctional rhythm has the same ECG features as junctional rhythm and junctional tachycardia. This rhythm is differentiated from the other junctional rhythms by the heart rate. Accelerated junctional rhythm is an uncommon dysrhythmia.
Accelerated junctional rhythm may result from enhanced automaticity of the AV junction caused by digitalis toxicity (the most common cause). The dysrhythmia may also be caused by damage to the AV junction from myocardial infarction (MI), especially an inferior wall MI.
The heart rate associated with accelerated junctional rhythm is not usually a problem because it corresponds to that of the sinus node (60 to 100 beats/minute). Signs and symptoms are more likely to occur from the loss of the atrial kick secondary to retrograde atrial depolarization, resulting in decreased cardiac output. Treatment is directed at reversing the consequences of reduced cardiac output, if present, as well as identifying and correcting the underlying cause of the dysrhythmia. All medications should be reviewed and discontinued as prescribed.
Accelerated junctional rhythm: Identifying ECG features
Rhythm: Regular
Rate: 60 to 100 beats/minute
P waves: Inverted in lead II and occurs immediately before or after, or is hidden within the QRS complex
PR interval: Short, if present (0.10 second or less)
QRS complex: Usually normal (0.10 second or less)