Cor Triatriatum Dexter: The Largest Comprehensive Review in the Field on 124 Worldwide Cases (1968–Now)

BACKGROUND: Cor triatriatum dexter (CTD) is a rare congenital heart defect where a membrane divides the right atrium into two chambers, resulting from the incomplete regression of the right valve of the sinus venosus. Due to its rarity, only individual case reports and a limited number of case series have been published to date. This study constitutes the most extensive comprehensive review conducted in this area. Eight factors were evaluated: age at diagnosis, sex, clinical presentation, electrocardiographic findings, imaging (ultrasound, CT, or MRI), associated cardiac anomalies, and patient outcomes. METHODS: The electronic databases PubMed and Scopus were searched from their inception until 30 October 2025. Only case reports and case series were considered for inclusion. Studies involving foetuses, autopsies, and animals were excluded. The collected data were primarily presented as percentages. RESULTS: One hundred fourteen studies were found encompassing 124 patients. The mean age at diagnosis was 33.3 ± 9.4 years The most common clinical presentations were dyspnoea (44.3%) and cyanosis (29.5%). The most commonly encountered ECG changes were supraventricular tachycardia/atrial flutter/atrial fibrillation (33.3%) and right bundle branch block (22.6%). On chest X-ray, cardiomegaly was noted in 46.5%. CTD was suspected or diagnosed by echocardiography in 95.2% of cases. The diagnosis was confirmed by CT and/or MRI in 34.1% of cases. A concomitant congenital heart defect was found in 67.7%, especially in the form of all kinds of atrial septal defect (38.1%) and of right valvular and right ventricular involvement (20.1%). An outcome was reported in 97/124. Surgical correction was the treatment of choice in 51.6%. Since 1991, a percutaneous approach has been employed in selected cases (5.1%). Conservative management was the treatment of choice in 43.3%. The mortality rate was 8.2%. DISCUSSION: The principal limitation of this systematic review lies in its reliance solely on case reports and small case series, reflecting the absence of large-scale studies on CTD. Nonetheless, it constitutes the most comprehensive analysis available to date.