Quick Arrhythmia Guide
First Degree Heart Block
| Rhythm | Regular |
| Rate | The underlying rate |
| P Wave | Normal |
| PR Interval | Prolonged (>0.20 sec) |
| QRS | Normal (0.06-0.10 sec) |
| Notes | A first degree AV block occurs when electrical impulses moving through the Atrioventricular (AV) node are delayed (but not blocked). First degree indicates slowed conduction without missed beats. |
First Degree Heart Block EKG Reference Arrhythmia Guide
Arrhythmia Guide