Deviation of atrial septum primum in association with normal left atrioventricular valve size

Leftward and Posterior Deviation of the Septum Primum Predicts Morbidity in Patients with Hypoplastic Left Heart Syndrome

Leftward posterior deviation of the atrial septum primum (LDSP) has been reported in up to 64% of patients with hypoplastic left heart syndrome (HLHS) but there are no published data on its impact on neonatal outcomes. We reviewed the prevalence of LDSP and its correlation with neonatal outcomes in our institution. This was a single-center retrospective study of neonates with HLHS from 2001 to 2019. Echocardiograms were reviewed and the presence or absence of LDSP was noted. To quantify the degree of deviation in patients with LDSP, a new measurement, the deviation index (DI) was calculated using both the subcostal long and short-axis views. Of ninety-four patients with HLHS, fifty-seven (61%) patients were noted to have LDSP. There was no statistically significant difference in gestational age (GA), birth weight (BW), or mortality between patients with and without LDSP. Patients with LDSP had an increased incidence of unplanned reoperation (p < 0.01), post-operative cardiac catheterization (p < 0.05), and post-operative infection (p < 0.05). After correction for GA, BW, HLHS subtype, and type of surgery, LDSP predicted reoperation (OR = 3.6, p < 0.01), catheterization (OR = 2.7, p = 0.05), and infection (OR = 3.4, p < 0.05). Higher degree of deviation predicted reoperation (DI > 0.17), catheterization (DI > 0.07), and infection (DI > 0.12). There was excellent inter-observer reproducibility of the DI (ICCabsolute-agreement = 0.82, ICCconsistency = 0.90). Patients with LDSP have a higher prevalence of post-operative morbidity. The degree of deviation was found to be predictive of post-operative complications. Pre-operative echocardiographic evaluation of LDSP in patients with HLHS may be helpful in risk stratification and counseling.

Divided left atrium with totally anomalous drainage of normally connected pulmonary veins

In the December 2021 issue of Cardiology in the Young, Hubrechts and colleagues, from Brussels and Leuven in Belgium, describe their experience in which the pulmonary veins were normally connected to the morphologically left atrium. By virtue of the presence of a shelf dividing the morphologically left atrium, however, the venous return was to the morphologically right atrium, with no evidence of formation of the superior interatrial fold, meaning that there was no obstruction of flow into the systemic venous circulation. The question posed by the Belgian authors is whether the shelf dividing the morphologically left atrium is a deviated primary atrial septum, as the arrangement has previously been interpreted. As they discuss, it is currently impossible to arbitrate this conundrum. In our commentary, we discuss the background to the dilemma. We point out that, as yet, it is not possible to code accurately this congenital cardiac malformation within The International Paediatric and Congenital Cardiac Code (IPCCC), nor within the newly produced 11th Revision of the International Classification of Diseases (ICD-11).

Leftward deviation of the primary septum or dividing left atrial shelf?

Isolated leftward prolapse or deviation of the primary atrial septum is a rare CHD that can mimic abnormal pulmonary venous return at first sight. We present a case of a newborn infant, referred for surgical correction of totally anomalous pulmonary venous return into the right atrium, with the peri-operative finding of a leftward deviation of the superior margin of the primary atrial septum. The distinction with a dividing atrial shelf could not be confirmed with certainty. Fifty-three similar cases from the literature are incorporated. A detailed review of the current account on atrial septation is studied. The embryological and clinical features of a dividing partition of the left atrium are discussed.

A rare cause of abnormal pulmonary venous drainage: septum primum malposition

OBJECTIVES

This study aimed to evaluate the clinical features of patients with septum primum malposition, imaging tools used for diagnosis, and their effects on the surgical approach.

MATERIALS AND METHODS

Patients diagnosed with septum primum malposition in our paediatric cardiac centre between 1 January, 2015 and 1 January, 2019 were included in the study. In all patients, the age, reason for admission, transthoracic echocardiography, cardiac multidetector CT angiography findings, and subsequent surgical data were evaluated.

RESULTS

Fifteen patients were diagnosed with septum primum malposition during the study period. The median age was 12 months (2 months-10 years). Six patients were left isomeric, and the rest were situs solitus; 80% of the patients (n = 12) had additional secundum atrial septal defect. There was cardiac pathology in 46% of the patients (n = 7) in addition to the abnormal pulmonary venous drainage, ventricular septal defect (n = 3), left ventricularhypoplasia (n = 2), cortriatriatum sinister (n = 2), double outlet right ventricle (n = 1), and atrioventricular septal defect (n = 1). There was bilateral superior caval vein in three patients, right-sided superior caval vein in 11 patients, and left-sided superior caval vein in one patient. All three patients with total abnormal pulmonary venous drainage were left atrial isomeric. There were differences between the results of transthoracic echocardiography and CT angiographies in two patients. The surgical strategy was changed in three patients after the preoperative diagnosis of septum primum malposition.

CONCLUSION

Septum primum malposition should be kept in mind during the imaging of complex CHDs specifically during the segmental analysis of the pathologies with heterotaxy syndromes; it should be differentiated from other aetiologies of abnormal pulmonary venous drainage as accurate diagnosis would facilitate the ideal surgery in these complex pathologies requiring a detailed preoperative preparation.

Echocardiographic Discovery of Doubled Interatrial Septum

A double-walled interatrial septum is a rare congenital cardiac anomaly characterized by a distinct echolucent cavity between the atria formed by 2 separate interatrial septae. It may be a variant of other well-recognized cardiac anomalies such as persistent venous valve of the sinus venosus or cor triatriatum. Although uncommon, it may be associated with thromboembolic disease due to stagnant flow in the septal cavity. Awareness of this rare entity and its clinical significance along with a thorough echocardiographic examination to rule out similarly presenting or coexisting conditions are the key to an accurate diagnosis and appropriate management.

Double atrial septum with interatrial chamber formation and recurrent paradoxical embolism

Paradoxical embolism is a common cause of cryptogenic stroke. Cardiogenic origin is often the real culprit of unexplained stroke. We report a rare case of double atrial septum with an interatrial chamber and stenosis of the inferior vena cava orifice, which lead to recurrent paradoxical embolism, and then highlight the clinical importance of this rare type of congenital heart disease.