Very rare congenital heart defect in which one of the atria is divided into 2 compartments. This can provoke an obstruction to the filling of the underlying ventricle. There exists a left form (sinister) (0.1 % of all cardiac abnormalities) and a much rarer rigth form (dexter).

It usually results from the abnormal persistence of an embryonic structure. The symptomatology depends on the importance of the atrial division (fenestrated or not): so, some cases are asymptomatic (30 %), others are associated with other malformations: ASD, total or partial abnormal pulmonary venous return, Ebstein's disease. It can present a clinical picture of mitral stenosis with pulmonary hypertension, or tricuspid stenosis, or heart rhythm disorders from atrial origin.

Anesthetic implications: 

according to the associated anomalies, the presence of a functional atrial  obstacle or of a shunt. In case of left cor triatriatum, any additional cause of pulmonary hypertension should be avoided (as in case of fluid overloading or hypoxemia). Caution should be exercised from the 20th week of pregnancy, during labour and in the immediate postpartum: risk of heart failure in a clinical picture of mitral stenosis. In case of right cor triatriatum, there is a pulmonary hypoperfusion with risk of cyanosis and signs of hepatic and renal dysfunction. CVP is elevated due to the impaired filling of the R.V.. Any tachycardia or atrial sinus rhythm disruption should be avoided to optimize the preload of the R.V.

References : 

-         Hoye DJ, Wilson EC, Fyfe DA, Guzzetta NA. 
Cor triatriatum dexter : a rare cause of neonatal cyanosis. 
Anesth Analg 2010; 110:716-8.

-         Bojanic K, Bursac D, Zmijanac J, Duic Z, Scavonetto F, Weingarten TN, Sprung J.
 Isolated cor triatriatum sinistrum and pregnancy: a case report and review of the literature. 
Can J Anesth 2013; 60: 577-83.

-        Jha AK, Makhija N.
Cor triatriatum : a review.
Sem Cardiothor Vasc Anesth 2017 ; 21 : 178-85

Updated: February 2018