Adult Echocardiography Practice Exam

Which fibrous structure might be found in the right atrium?

1. Moderator band

2. Coronary sinus

3. Chiari's network

4. Eustachian valve

The correct answer is: Chiari's network

In the right atrium, Chiari's network is a fibrous structure that can be present. This structure is a remnant of the embryonic development of the heart and consists of a meshwork of fibers that may appear as thin strands or filaments. It is located in the right atrium, often around the entry of the inferior vena cava, and can occasionally be mistaken for a thrombus or other abnormality on imaging studies. The presence of Chiari's network can vary among individuals, and while it is not always seen, its identification is important for interpreting echocardiographic exams accurately. It is noteworthy that while it is a normal variant, Chiari's network has been associated with certain cardiac conditions, including a predisposition to embolic events. In contrast, the moderator band is primarily found in the right ventricle and serves to support the conduction system, and the coronary sinus is a component of the venous drainage system, receiving blood from the cardiac veins into the right atrium. The Eustachian valve, which is a remnant of embryonic development and directs blood flow from the inferior vena cava towards the foramen ovale, is also present in the right atrium, but it is not classified as a