Analyzing a Rhythm
| Component | Characteristic |
|---|---|
| Rate | The bpm is commonly the ventricular rate. If atrial and ventricular rates differ, as in a 3rd-degree block, measure both rates. Normal: 60-100 bpm Slow (bradycardia): less than 60 bpm Fast (tachycardia): greater than 100 bpm |
| Regularity | Measure R-R intervals and P-P intervals. Regular: Intervals consistent Regularly irregular: Repeating pattern Irregular: No pattern |
| P Waves | If present: Same in size, shape, position? Does each QRS have a P wave? Normal: Upright (positive) and uniform Inverted: Negative Notched: P’ None: Rhythm is junctional or ventricular. |
| PR Interval | Constant: Intervals are the same Variable: Intervals differ Normal: 0.12-0.20 sec and constant |
| QRS Interval | Normal: 0.06-0.10 sec Wide: greater than 0.10 sec None: Absent |
| QT Interval | Beginning of QRS complex to end of T wave Varies with HR Normal: Less than half the RR interval |
| QTc Interval | The QTc interval is the QT interval corrected for the heart rate. Formula for calculating QTc: QTc = QT divided by the square root of the R to R interval Normal corrected QTc should be less than 0.44 seconds. |
| Dropped beats | Occur in AV blocks Occur in sinus arrest |
| Pause | Compensatory: Complete pause following a premature atrial contraction (PAC), premature junctional contraction (PJC), or premature ventricular contraction (PVC) Noncompensatory: Incomplete pause following a PAC, PJC, or PVC |
| QRS Complex grouping | Bigeminy: Repeating pattern of normal complex followed by a premature complex Trigeminy: Repeating pattern of 2 normal complexes followed by a premature complex Quadrigeminy: Repeating pattern of 3 normal complexes followed by a premature complex Couplet: 2 Consecutive premature complexes Triplet: 3 Consecutive premature complexes |
Classification of Arrhythmias
| Heart Rate | Classification |
|---|---|
| Slow | Bradyarrhythmia |
| Fast | Tachyarrhythmia |
| Absent | Pulseless arrest |
Normal Heart Rate (bpm)
| Age | Awake Rate | Mean | Sleeping Rate |
|---|---|---|---|
| Newborn to 3 months | 85-205 | 140 | 80-160 |
| 3 months to 2 years | 100-190 | 130 | 75-160 |
| 2 to 10 years | 60-140 | 80 | 60-90 |
| greater than 10 years | 60-100 | 75 | 50-90 |