Unroofed coronary sinus

Last revised by Sonam Vadera on 28 May 2022

An unroofed coronary sinus, a.k.a. coronary sinus type ASD, is a rare variant of atrial septal defect (ASD). The atrial wall between the coronary sinus and left atrium is either partially or completely absent, resulting in a right-to-left shunt.

It is associated with persistent left-sided superior vena cava and heterotaxy syndromes.

Clinical presentation is variable and depends on the degree of right-to-left shunting. When there are associated symptoms it is then often termed unroofed coronary sinus syndrome (URCS) 4.

Unroofed coronary sinus has been classified into 4 groups:

  • type I: completely unroofed with persistent left-sided superior vena cava
  • type II: completely unroofed without persistent left-sided superior vena cava
  • type III: partially unroofed mid-portion
  • type IV: partially unroofed terminal portion

The diagnosis is often made on transthoracic echocardiography, but because of the deep position of the anomaly within the chest, transesophageal echocardiography, cardiac CT, or cardiac MRI may also be useful.

ADVERTISEMENT: Supporters see fewer/no ads