A Systematic Review of a Long-forgotten Cause of Atrial Fibrillation and Stroke: Cor Triatriatum

Case report: The impact of percutaneous atrial septal defect closure in pulmonary hypertension with co-existing cor triatriatum sinister and multiple cardiac comorbidities

Cor triatriatum sinister is a rare congenital anomaly characterized by the left-sided triatrial form of the heart. Diverse theories have been proposed regarding its formation, and the failure of incorporation of the common pulmonary vein into the left atrium (LA) during embryogenesis is the most widely accepted theory. Accordingly, cor triatriatum sinister may be associated with pulmonary venous obstruction and post-capillary pulmonary hypertension in the setting of restricted fenestration. A high proportion of patients with cor triatriatum sinister also have an associated secundum atrial septal defect. Pre-capillary pulmonary hypertension, which is unusual in patients with small atrial septal defects (<2 cm), is probably not as rare as some reports indicate, especially when combined with complex comorbidities. The conventional treatment strategy of atrial septal defect closure in patients with pulmonary hypertension, whether associated with cor triatriatum sinister or co-existing multiple cardiac anomalies, involves simultaneous repair with other cardiac surgical procedures. To the best of our knowledge, there is no reported clinical experience of percutaneous atrial septal defect closure in the literature. Herein, we present the case of an elderly female with pulmonary hypertension and coexisting cor triatriatum sinister, secundum atrial septal defect, and multiple cardiac anomalies. Despite optimal medical therapy, the biventricular failure deteriorated, and clinical stabilization could not be achieved. Transcutaneous atrial septal defect closure was then performed. Subsequent investigations showed an initial improvement (perhaps due to elimination of the left-to-right shunt) from this intervention, but the long-term impact did not appear favorable, likely due to multiple uncorrected cardiac anomalies. To the best of our knowledge, this is the first clinical report showing that partial treatment of combined pre- and post-capillary pulmonary hypertension by eliminating the pre-capillary component may have an initial benefit; thus, total surgical correction should be considered a definite therapeutic strategy unless contraindicated.

Atrial Fibrillation Ablation in a Patient with Cor Triatriatum Sinister and Left Common Pulmonary Vein: Impact of Left Atrium Anatomy on Ablation Approach

Atrial fibrillation is the most common presentation in adult patients with cor triatriatum sinister. The key to successful and safe catheter ablation in these patients is an accurate exploration and thorough understanding of the left atrial anatomy, both before and during the procedure. Catheter manipulation is highly dependable on left atrial anatomy, including the interatrial septum, insertion of pulmonary veins and cor triatriatum membrane. Anatomical variants such as the left common pulmonary trunk may influence the ablation approach and outcome. We report the case of a 52-year-old patient with cor triatriatum sinister and the left common pulmonary vein variant who underwent successful high-power, short-duration catheter ablation for paroxysmal atrial fibrillation.

Cor Triatriatum Dexter: Contrast Echocardiography Is Key to the Diagnosis of a Rare but Treatable Cause of Neonatal Persistent Cyanosis

Cor triatriatum dexter (CTD) is an extremely uncommon and underreported congenital cardiac anomaly in which the persistence of the embryonic right venous valve separates the right atrium into two chambers with varying degrees of obstruction to antegrade flow and variable degree of right to left shunt at atrial level. Depending on the size of the valves, clinical manifestations vary from absence of symptoms to severe hypoxia, requiring urgent surgical correction. We herein describe the diagnostic difficulties in a case of neonatal CTD, who developed increasingly severe and unresponsive cyanosis, first interpreted as postnatal maladjustment with pulmonary hypertension. The failure to respond to oxygen and pulmonary vasodilators led us to reconsider a different diagnosis. The use of contrast echocardiography improved the diagnostic performance of transthoracic echocardiogram (TTE) and revealed a massive right-to-left shunt secondary to the presence of an atrial membrane that required urgent surgery.