The QRS Complex
| CHARAC. | PR INTERVAL | CONSIDER |
| Normal | 0.06 to 0.10 seconds (1.5 to 2.5 small boxes) | |
| Narrow | < 0.06 seconds | Not usually indicative of a problem |
| Wide | >0.12 seconds | Consider ventricular rhythm or bundle branch block, especially if the complex is notched, like “rabbit ears” |
