Cor triatriatum is an extremely rare and serious congenital cardiac anomaly.
It is thought to account for ~0.1% of all congenital cardiac anomalies 3,4.
Clinical presentation depends on:
- degree of stenosis in the fibromuscular membrane
- the integrity of the interatrial septum
- presence of associated cardiovascular malformations.
It can be a cause of unexplained pulmonary hypertension in children. Typical presentation includes dyspnea, heart failure, and failure to thrive 5.
There are two recognized subtypes:
- classic cor triatriatum (cor triatriatum sinistrum / sinister): commoner
- cor triatriatum dextrum/dexter 4
In the classical type, there is an abnormal incorporation of pulmonary venous structures into the left atrium with an unnecessary fibromuscular membraneous subdivision through the atrial chamber.
With cor triatriatum dexter a similar scenario is seen through the right atrium.
Cor triatriatum exists along a spectrum from an imperforate membrane to a membrane with fenestrations, which may allow some passage of blood flow. A highly fenestrated membrane in cor triatrum dexter is sometimes referred to as a Chiari network.
An isolated cor triatriatum demonstrates chest x-ray changes identical to that of mitral stenosis: the heart is normal sized with changes of chronic interstitial edema.
The intra-atrial membrane characteristic of classic cor triatriatum is often best visualized in the transthoracic apical 4 chamber view, with the following features often observed 6;
- echogenic, linear density subdividing the left atrium into proximal (inferior) and distal (superior) chambers
- extends from the posteroinferior to the anterosuperior atrial wall
- proximal chamber will typically receive the pulmonary venous drainage
- distal chamber usually communicates with the mitral valve and atrial appendage
- use of color flow Doppler allows confirmation of the communication between atrial subdivisions
- low velocity flow typically demonstrated with pulsed wave Doppler
- common associations which should be sought include
May allow direct visualization of membrane +/- accessory chamber in greater detail.
Treatment and prognosis
A cor triatriatum is usually fatal within the first two years of life. The membrane can be surgically resected. The prognosis is related to timely surgical intervention, the degree of obstruction between the two left atria and the presence or absence of associated anomalies 5.
History and etymology
The word cor triatriatum essentially means "heart with three atria" due to the accessory chamber created by the membrane appearing as an extra atrium.
- 1. Dillman JR, Yarram SG, Hernandez RJ. Imaging of pulmonary venous developmental anomalies. AJR Am J Roentgenol. 2009;192 (5): 1272-85. doi:10.2214/AJR.08.1526 - Pubmed citation
- 2. Bisset GS, Kirks DR, Strife JL et-al. Cor triatriatum: diagnosis by MR imaging. AJR Am J Roentgenol. 1987;149 (3): 567-8. AJR Am J Roentgenol (citation) - Pubmed citation
- 3. Arrants JE, Riopel DA, Catalano PW. Cor triatriatum: preoperative diagnosis and successful surgical correction in a ten-week-old infant. Chest. 1973;63 (6): 1027-8. doi:10.1378/chest.63.6.1027 - Pubmed citation
- 4. Joe BN, Poustchi-amin M, Woodard PK. Case 56: cor triatriatum dexter. Radiology. 2003;226 (3): 701-5. doi:10.1148/radiol.2263001845 - Pubmed citation
- 5. Jolles H, Henry DA, Rupp SB. General case of the day. Cor triatriatum. Radiographics. 1988;8 (6): 1227-31. Radiographics (citation) - Pubmed citation
- 6. Scott D Solomon, Justina Wu, Linda D. Gillam. Essential Echocardiography: A Companion to Braunwald’s Heart Disease E-Book. (2017) ISBN: 9780323508728
Related Radiopaedia articles
Congenital heart disease
There is more than one way to present the variety of congenital heart diseases. Whichever way they are categorized, it is helpful to have a working understanding of normal and fetal circulation, as well as an understanding of the segmental approach to imaging in congenital heart disease.
congenital heart disease
- normal relationship between chambers and valves
- atrioventricular valves
- outflow tract
- great vessels
- venous inflow
- anomalous valves
- abnormal relationship of chambers and valves
- atrioventricular abnormality
- great vessel connection abnormality
- conotruncal cardiac anomalies
- pentalogy of Cantrell
- Shone syndrome
- congenital heart disease - chest x-ray approach
surgical repairs (mnemonic)
- arterial switch procedure
- Blalock-Taussig shunt
- double switch procedure
- Fontan procedure
- Glenn procedure
- Mustard repair
- Norwood procedure
- Pott shunt
- pulmonary artery banding
- Rastelli procedure
- Sano shunt
- Senning repair
- total repair of tetralogy of Fallot (TOF)
- unifocalisation procedure
- Waterston shunt