Dysrhythmias

Diagnostic Algorithm

1. Determine the ventricular rate – note paper speed.
2. Determine the atrial rate – note paper speed.
3. Are P and QRS associated?
   • same rate
   • reasonable PR interval
   • consistent PR interval
4. Determine PR interval – note paper speed
   • does it vary?
5. Are there any P waves that are not followed by a QRS complex?
6. Are there any QRS complexes with no P waves?
7. Determine the width of the QRS complexes – note paper speed.
8. Is the rhythm regular or irregular?
9. Any premature beats? – note morphology and duration
10. Are the P waves positive in lead II?
11. Are the QRS complexes of normal morphology?

The critical feature with most dysrhythmias is to identify P waves (if present), note if the atrial rate is equal to, less than, or greater than the ventricular rate, and note if there is any relationship between the P waves and the QRS complexes.