Cor Triatriatum: an uncommon congenital anomaly - the experience of a tertiary care center in a developing country

Abstract

Background: Cor Triatriatum is a congenital anomaly characterized by the abnormal presence of a fibromuscular junction in one of the atria, as seen on echocardiography. This anomaly can lead to major hemodynamic problems and obstruction of blood flow. This study aims to explore the risk factors, diagnostic modalities, and surgical interventions used to tackle this congenital anomaly at a tertiary care center over an 18-year period.

Materials and methods: Medical records of congenital heart disease patients at the Children's Heart Center at the American University of Beirut Medical Center between 2006 and 2024 were retrospectively reviewed. Data collection included demographic characteristics, clinical outcomes, hospitalization details, and surgical treatment. Ethical approval was obtained, and descriptive statistics were employed for data analysis using SAS 9.4.

Results: At our center, 7 patients were diagnosed with Cor Triatriatum, with a median age of 5 months. 4 of the patients were female, 3 were males, and the median hospital stay was 7 days. All patients were diagnosed with Cor Triatriatum Sinister, and respiratory symptoms were prevalent. Pulmonary vein abnormalities were observed in 4 ouf of 7 (57.1%) patients and atrial septal defects in 2 out of 7 patients (28.5%). Surgery resulted in successful membrane resection for all operated patients, with significant symptom improvement postoperatively.

Conclusion: Cor Triatriatum is a rare congenital anomaly requiring early detection and diagnosis. Surgical intervention remains the mainstay of treatment, with favorable outcomes when performed promptly. Larger studies are recommended to optimize management strategies and improve long-term outcomes for affected patients.

Keywords: Cor Triatriatum; blood flow obstruction; congenital heart disease; congenital heart surgery; echocardiography.

Figure 1

The echocardiogram shows an abnormal membrane or fibromuscular partition that divides the left atrium into two chambers. This partition separates the pulmonary venous inflow, creating a proximal and distal chamber. Notable in this image are the membranous structures and potential flow obstruction, which are typical in Cor Triatriatum cases. The relevant chambers are labeled with *RA: Right Atrium, *RV: Right Ventricle, *LA: Left Atrium, *LV: Left Ventricle, *CTS: Cor Triatriatum Sinister.

Figure 2

This echocardiogram highlights the turbulent flow pattern within the left atrium, as seen in the color Doppler display. The blue and red color signals indicate a high-velocity flow across the membranous partition within the atrium, characteristic of Cor Triatriatum. The arrow is pointing towards a small restrictive communication present in the membrane, reinforcing the diagnosis and illustrating potential hemodynamic implications.

Figure 3

This CT image highlights the fibromuscular membrane dividing the left atrium into two chambers. Visible on the scan is the Cor membrane, which acts as a partition within the atrium, creating a distinct proximal and distal chamber. The proximal chamber receives the pulmonary veins, while the distal chamber channels blood to the mitral valve, leading to the left ventricle. The scan shows the unusual entry points of the pulmonary veins: the roots of two pulmonary veins are depicted entering the roof of the right atrium, an anomalous connection indicative of PAPVR. In contrast, the roots of the two other pulmonary veins are seen entering the left atrium, following the normal anatomical pattern. This difference between normal and abnormal venous connections highlights the unique challenges posed by Cor Triatriatum.

Figure 4

(A) Group 1 Loeffler classification of Cor Triatriatum. (B) Group 2 Loeffler classification of Cor Triatriatum. (C) Group 3 Loeffler classification of Cor Triatriatum.