RBBB and LPFB on ECG represent a specific type of bifascicular block. Bifascicular block occurs when two of the three main conduction pathways in the heart are blocked. In the case of RBBB and LPFB, the right bundle branch and the left posterior fascicle are blocked.
Clinically, this combination manifests a specific pattern on an electrocardiogram (ECG). According to the provided reference, right bundle branch block (RBBB) with left posterior fascicular block (LPFB) is manifested as right axis deviation (RAD) in the absence of other causes.
To better understand, let's break down the components:
- RBBB (Right Bundle Branch Block): This means the electrical impulse is blocked in the right bundle branch, delaying the depolarization of the right ventricle.
- LPFB (Left Posterior Fascicular Block): This indicates a blockage in the left posterior fascicle, one of the divisions of the left bundle branch, affecting the depolarization of the inferior part of the left ventricle.
Therefore, the ECG will show a right bundle branch block pattern, along with right axis deviation, indicative of the blocked left posterior fascicle.
In summary:
| Condition | ECG Manifestation |
|---|---|
| RBBB and LPFB | Right axis deviation (RAD) in the absence of other causes. |
