Cor triatriatum is a rare heart defect that makes up about 0.1% of all congenital cardiac malformations [1]. The literal meaning of this term is a heart with three atria instead of two.

Historically, it was first described in 1868 by Church W.S. who presented a case of abnormal septum dividing the left atrium into (upper/superior) proximal and distal (lower/inferior) [2]. Since then, few hundreds of cases have been reported worldwide [3]. In 1905, Borst H. was the first to give this abnormality its name [4]. Cor triatriatum can be divided into two types. The first one is cor triatriatum sinister (CTS) in which the septum (fibromuscular band) separates the left atrium (LA) into two parts and this type is more common accounting for 83% of all cases. The second type, cor triatriatum dexter (CTD), is extremely rare and accounts for 17% of all cases where the right atrium (RA) is made up of two chambers [5].

The median age at presentation is 6 months; with tachypnea, failure to thrive and decreased oral intake being the three most common complaints [6]. Presentation of CTS usually includes the following: tachypnea, respiratory distress, hemoptysis and hypoxemia which may be misdiagnosed as bronchial asthma, bronchitis or pulmonary tuberculosis. On the other hand, CTD presentation resembles signs right cardiac failure including edema and hepatomegaly [7].

Here we present the case of 7 months old girl presenting with recurrent respiratory complaints discovered to have cor triatriatum sinister.

Case Description

History and Presentation: A 7 months old baby girl, presented to the emergency department of Sahel General University Hospital with cough, fever and tachypnea that lasted for 2 days prior to presentation. Her mother mentioned recurrent episodes of similar respiratory presentation at ages of 3 and 5 months. Both were severe enough to require hospitalization for intravenous antibiotics, nebulized bronchodilators and oxygen support through a face mask. Each admission to the hospital lasted for 10 days.

On physical examination, the baby was looking ill. Her chest examination revealed decreased movements of the left chest with reduced air entry to the left lung and mild inspiratory wheezes. She had regular heart sounds with no audible murmurs on auscultation.

Diagnostic Focus and Assessment

Vital signs on presentation showed a febrile baby girl with body temperature of 39 degrees Celsius. She was also tachycardic and tachypneic. Oxygen saturation measured on room air was 85%. Anthropometric measurements revealed a weight of 6.5 kg and a height of 62 cm, both of which are below the 5^th percentile for her age when illustrated on growth chart.

Blood samples were drawn out and results are shown in Table 1 and also shown in Table 2.

A chest X-ray was done on presentation and revealed a consolidation in the upper lobe of the left lung (Figure 1).

Figure 1: Chest X-Ray Done on Presentation Showing Upper Lobe Opacities (red circle).

Therapeutic Focus and Assessment

Patient was admitted to the pediatric floor and started on intravenous antibiotics (Ceftriaxone and Clarithromycin) for pneumonia. Also, she was placed on oxygen by nasal canula due to desaturation on room air. In addition, nebulized bronchodilators were administered as needed. Anti-pyretic was also given for fever as required.

Table 1: Hematology Laboratory Test Results

Table 2: Biochemistry Laboratory Test Results

Two days later, patient was still in distress with nasal flaring and subcostal retractions. Further workup was done including Influenza A and B rapid test and RSV test. All of which came back to be negative. Three days later, fever resolved but respiratory symptoms showed no improvement.     

Now a cardiac origin of these complaints was suspected so cardiac ultrasound was performed and showed a left atrium divided into two chambers with post-capillary pulmonary artery hypertension (Figure 2). So, the diagnosis of cor triatriatum sinister was established and the patient required urgent surgical correction. Patient’s condition improved significantly post-operative intervention and was discharged home with no complaints.

Figure 2: Echocardiography Showing Cor Triatriatum Sinister

Cor triatriatum is a rare congenital heart defect where a septum divided the atrium into 2 chambers. It can affect the left atrium and thus termed cor triatriatum sinister (CTS) or the right atrium and accordingly named cor triatriatum dexter (CTD). No clear embryological origin has been described to definitely explain this anomaly. The three proposed theories include mal-septation, entrapment and mal-incorporation [8,9,10].

The clinical presentation varies depending on the severity of the lesion and the associated anomalies. Symptoms may resemble tricuspid valve (TV) stenosis or mitral valve (MV) stenosis depending whether it is a CTD or a CTS. When cor triatriatum is associated with other heart defect(s), it can be referred to as atypical but when it is isolated it can be termed classic [3]. Cor triatriatum sinister is most commonly accompanied with: atrial septal defect (ASD), patent ductus arteriosus, and anomalous pulmonary venous return [11].

Loeffler described a simple way to classify CTS in 1949 by dividing this anomaly into three groups based on the number and size of the openings within the LA; first group is the one where no communication existed through the intra-atrial septum, second group where one or few openings connect the proximal and the distal chambers, and a third group where a single large opening exists within the intra-atrial membrane. Accordingly, the first two groups present during early childhood and infancy due to severity of symptoms, while the third group is characterized by a late presentation that can be delayed till adulthood [12].

Regarding diagnosis, electrocardiography (ECG) may be normal or shows tachycardia in some cases. Cardiac echocardiography is very helpful especially when searching for an associated anomaly. Also, 3D-TTE (3 dimensional-trans-thoracic echocardiography) helps in measuring the location of orifices and counting their number [13].

Treatment of symptomatic patients is usually surgical with intraoperative cardiopulmonary bypass with a survival rate greater than 90% at 5 years [6]. Besides surgery, medical management can be incorporated to prevent pulmonary congestion and cardiac failure by using inotropic agents such as Digoxin and diuretics to decrease volume overload. Also, in certain circumstances thromboembolic prophylaxis is required such as when right heart failure leads to venous stasis. Rarely full anti-coagulation may be necessary such as cases of atrial fibrillation [14].

In the above described case, presentation took the form of recurrent respiratory distress that required hospitalization. Treatment was through the resection of the accessory membrane that was well tolerated.

Recurrent respiratory complaints during infancy and early childhood must raise the suspicion of a congenital cardiac anomaly. One of those anomalies being cor triatriatum which is a rare condition or in other terms a rarely diagnosed and reported anomaly. This malformation must be surgically treated as early as possible to avoid cardiac and extra-cardiac complications and to improve the quality of life of both the patient and the family.

Conflict of Interest

None

Declaration of Patient Consent

The patient and her family agreed on publishing the data (including the laboratory and imaging results with pictures) while keeping her identity anonymous.

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