Which of the following describes a right bundle branch block?

A right bundle branch block (RBBB) is characterized by a specific pattern observed on an electrocardiogram (ECG). The key features of RBBB include a widened QRS complex exceeding 0.12 seconds due to delays in the conduction of impulses through the right bundle branch. This causes the right ventricle to depolarize later than the left ventricle, leading to a characteristic appearance of the QRS complex.

In leads V1 and V2, RBBB typically manifests as an rSR' pattern, often described as a "double-peaked" morphology. This morphology arises because the delayed depolarization of the right ventricular myocardium produces a second R wave (R') in the QRS complex, while the left ventricle depolarizes normally.

Understanding this descriptive pattern is essential, as it allows healthcare providers to recognize RBBB quickly, assess its potential clinical significance, and determine whether further investigation or treatment is necessary.