We present images from an echocardiogram and a cardiovascular tomodensitometry for a rare congenital cardiac anomaly associating a cor triatriatum with a partial anomalous pulmonary venous return.
A 14-year-old girl was referred to our hospital for pulmonary arterial hypertension and an atrial septal defect.
At admission, she belonged to New York Heart Association functional class 3; there was a widely slammed second heart sound and a protomesodiastolic murmur at the cardiac apex. The percutaneous peripheral oxygen saturation was 99%, and the arterial blood pressure was 98/57 mmHg. Electrocardiograms revealed a sinus rhythm of 60/min, a right bundle branch block, and left atrial hypertrophy. Transthoracic echocardiographic examination revealed a severe obstructive fibromuscular membrane with a hole of less than four millimetres in the left atrium, resulting in a continuous transmembrane flow with a mean pressure gradient of 30 mmHg (Fig 1). The pulmonary artery pressure was severely increased with isosystemic pressure in the right ventricle. The atrial septum was intact. The diagnosis of a partial anomalous pulmonary venous connection was suggested by visualisation of the accelerated venous flow in the ductus arteriosus position – between the left pulmonary artery and the descendant aorta; this tortuous vein was draining through the innominate vein with an accelerated flow into the right atrium. The right cavities were dilated.
Figure 1 Apical four-chamber echocardiographic images showing the fibromuscular membrane (FM) in the left atrium (LA). LV = left ventricle; RA = right atrium; RV = right ventricle.
Cardiovascular tomodensitometry was performed and confirmed the diagnosis of cor triatriatum and a left upper anomalous pulmonary venous return. The tortuous draining vein was compressed between the aorta and the left pulmonary artery with suspicion of a passage between the left upper anomalous pulmonary venous return and the left atrium (Fig 2).
Figure 2 Cardiovascular tomodensitometry scan showing the cor triatriatum membrane (CTM) and the left upper anomalous pulmonary venous in return (LUAPV), compressed between the aorta (A) and the left pulmonary artery (LPA) with an anastomosis between the left upper anomalous pulmonary venous return and the left inferior pulmonary vein (LIPV). LA = left atrium; Lap = left atrial appendage; LV = left ventricle.
A cardiac catheterisation confirmed a large anastomosis between the left upper pulmonary vein and the left inferior pulmonary vein.
The surgical treatment comprised only resection of the fibromuscular membrane, avoiding the left upper anomalous pulmonary venous return because of the large anastomosis between the left upper pulmonary vein and the left inferior pulmonary vein.
The post-operative transthoracic echocardiograph revealed disappearance of the left intra-atrial gradient, with a systolic pulmonary artery pressure of 25 mmHg. The patient still harbours the left upper anomalous pulmonary venous return but the flow is biphasic and unaccelerated.
Comment
Cor triatriatum is a rare but surgically correctable congenital cardiac anomaly accounting for 0.1% of all congenital cardiac malformations.Reference Locca, Hughes and Mohiaddin 1 , Reference Alphonso, Norgaard, Newcomb, d'Udekem, Brizard and Cochrane 2 It is defined by the presence of a more or less obstructive fibromuscular membrane that separates the proximal chamber receiving all the pulmonary veins and the distal chamber containing the left atrial appendage and the mitral valve. It is associated with other congenital cardiac anomalies in 24–80% of cases.Reference Alphonso, Norgaard, Newcomb, d'Udekem, Brizard and Cochrane 2 Anomalous venous return is a frequently associated condition in 11–53% of other congenital cardiac anomalies associated with cor triatriatum.Reference Alphonso, Norgaard, Newcomb, d'Udekem, Brizard and Cochrane 2 – Reference Krasemann, Scheld, Tjan and Krasemann 4 Many types of partial – left or right – or total anomalous pulmonary venous connections are described to the azygos vein, the innominate vein, and the coronary sinus.Reference Locca, Hughes and Mohiaddin 1 , Reference Hiramatsu, Komori, Okamura, Suzuki, Takeuchi and Shibuta 5 Lucas, in 1995, combined elements of several classifications of cor triatriatum into a comprehensive classification.Reference Herlong, Jaggers and Ungerleider 6 Our case report corresponds to 3A2 of Lucas's classification.
Embryogenesis remains controversial and is usually explained by citing the entrapment or malincorporation theory.Reference Van Praagh and Corsini 7
Cor triatriatum is mostly diagnosed during early childhood, and the severity of the clinical presentation depends on the degree of obstruction by the fibromuscular membrane, the stenosis of the pulmonary venous drainage, and the atrial septal defect.
Treatment of cor triatriatum is primarily surgical. There are two case reports of balloon dilatation with good results but with a follow-up of only 3 and 12 months after the procedure, respectively.Reference Huang, Lee, Lin, Tseng and Hsieh 8 , Reference Kerkar, Vora, Kulkarni, Narula, Goyal and Dalvi 9
The proposed reasons for a late conversion to a symptomatic state are believed to be caused by one or more of the following factors: development of atrial fibrillation or mitral regurgitation or fibrosis and calcification in the orifice of the fibromuscular membrane.Reference Chen, Guhathakurta, Vadalapali, Nalladaru, Easthope and Sharma 10
Our presentation of a 14-year-old girl differs from other case reports as there was no atrial septal defect but rather the presence of a left upper anomalous pulmonary venous return to the innominate vein that discharged significantly, similar to an atrial septal defect, into the proximal chamber from the severe intra-atrial obstruction. This explains the good clinical tolerance in our patient.
The large anastomosis between the left inferior pulmonary vein and the left upper pulmonary venous return authorised a simple surgery – resection of the fibromuscular membrane – without involvement of the pulmonary veins.
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