What does a "RBBB" signify when viewed on an ECG?

A Right Bundle Branch Block (RBBB) is indicated when there is a delay or blockage in the electrical conduction through the right bundle branch of the conduction system of the heart, as represented on an electrocardiogram (ECG). This condition typically manifests as a specific pattern of the QRS complex, which is usually wider than normal, measuring greater than 0.10 seconds.

On the ECG, an RBBB is characterized by a ‘M’-shaped appearance in the V1 and V2 leads, and a broad, notched R wave in leads V5 and V6. The purpose of identifying an RBBB is to understand how it can impact the heart's functioning, as it can sometimes be associated with underlying heart disease, but it may also occur in healthy individuals without symptoms.

Recognizing RBBB is essential for proper diagnosis and management in a clinical setting, as it differs significantly from other options such as left bundle branch block, myocardial infarction, or atrial fibrillation, which have distinct features and clinical implications. Understanding RBBB can aid healthcare professionals in making accurate assessments when interpreting ECGs.