Changes specifically seen include the QRS complex measuring 0.12 seconds or greater due to this delay.
When determining the presence of BBB there are just a few simple steps to follow.
- Step 1: Refer to lead V1
- Step 2: Look for evidence that the electrical activity started above the ventricles (P wave). This is sometimes referred to as supraventricular
- Step 3: QRS complex measures 0.12 seconds or greater (not including aberrant complexes i.e. PVCs)
Steps 1-3 (continued)
By following the previous three steps, you will be able to determine whether a BBB is present or not.
Now it is simply a matter of one more step when analyzing the QRS in V1 to distinguish whether it is a left BBB or a right BBB.