What are the ultrasound findings of right bundle branch block?

Right bundle branch block (RBBB) typically presents on ultrasound with findings such as delayed right ventricular contraction, increased right ventricular outflow tract resistance, and abnormal right ventricular wall motion. The specific manifestations are as follows:

1. Delayed Right Ventricular Contraction

Due to prolonged ejection time of the right ventricle, its morphology and systolic function are affected. During examination, prolonged right ventricular ejection time, reduced ejection velocity, and increased volume load in the right ventricle can be observed.

2. Increased Right Ventricular Outflow Tract Resistance

RBBB may lead to increased resistance in the right ventricular outflow tract, thereby increasing the right ventricular load. On examination, a reduced diameter of the right ventricular outflow tract, decreased flow velocity, and even regurgitation may be observed.

3. Abnormal Right Ventricular Wall Motion

RBBB can cause abnormal motion of the right ventricular wall, potentially manifesting as uncoordinated systolic and diastolic movements, or weakened or absent myocardial motion in the right ventricle.

In addition to the above findings, abnormal motion of the ventricular septum may also occur. Although ultrasound can assist in diagnosing these local abnormalities, diagnosis should be made by comprehensively considering clinical symptoms, electrocardiographic findings, and results from other diagnostic tests.