Chiari's network is a congenital remnant of the right valve of the sinus venosus.
Location: right atrium near the opening of the inferior vena cava and the coronary sinus.
Appearance: meshwork of thread-like strands extending to the crista terminalis or fenestrations in the inferior vena cava and coronary sinus valves
Frequency: 1-4% of autopsies
Usually it is a finding of little significance by itself.
Associations:
(1) patent foramen ovale with right-to-left shunting
(2) atrial septal aneurysm
(3) recurrent paradoxical arterial emboli
(4) physical barrier during invasive intracardiac procedures
(5) may be associated with neurofibromatosis
(6) may be associated with migraines
(7) possible ability to intercept venous emboli
It can be seen on echocardiography as highly mobile and reflectant echo targets in the right atrium.
