Morphological Study of Fossa Ovalis in Formalin-Fixed Human Hearts and Its Clinical Importance

Background and Objectives: Our study aimed to investigate the gross anatomy aspects of the fossa ovalis (FO) and the presence of some anatomical variation resulting from the incomplete fusion of septum primum and septum secundum, such as an atrial septal pouch (SP) and left atrial septal ridge. Materials and Methods: Thirty-one adult human hearts removed from formalin-fixed specimens were examined to provide information about the morphology of the FO. The organs were free of any gross anatomically visible pathological conditions. Results: The most common variants were the FO located in the inferior part of the interatrial septum (64.51%), circular (61.3%), with a net-like structure (51.62%), prominent limbus (93.55%), and patent foramen ovale (PFO) (25.8%). The right SP was observed in 9.67% of specimens, the left SP was observed in 29.03% of cases, and in 51.61% of cases, a double SP was observed. One sample presented a right SP and a double left SP, and one case showed a triple left SP, which was not reported previously to our knowledge. Conclusions: Knowledge of the interatrial septal anatomy becomes important for interventional cardiologists and should be documented before transeptal puncture.

Left atrial septal pouch in a six-year-old child: echocardiographic and magnetic resonance view

In a 6-year-old child patient, transthoracic echocardiography revealed a large saccular structure (with anechogenic content) in the left atrium, near the fossa ovalis, and diagnosis of the left atrial septal pouch was made. The left atrial septal pouch is a kangaroo pouch-like structure on the left side of the interatrial septum, opened into the left atrial cavity without a connection between the left and right atria. It occurs when the foramen ovale is absent but the septum primum and septum secundum are only partially fused. The left atrial septal pouch is believed to be present in 47% of population. In many cases, the pocket on the atrial septum is small and it could not be detected by transthoracic echocardiography. Our description is uncommon because we diagnosed a very large septal pouch. Based on our knowledge, this is the youngest reported case of the left atrial septal pouch and the longest follow-up described in this type of congenital heart malformation.

Malposition of septum primum in isolated dextrocardia: unique and rare form of anomalous pulmonary venous return in association with partial absence of pericardium-case report

Background Total anomalous pulmonary venous return (TAPVR) refers to an anomaly in which all of the pulmonary veins drain directly or indirectly to the systemic venous circulation. However, unusual types constitute approximately 5% or less of TAPVRs and there may be obstruction or discontinuity of pulmonary vein at various levels. Case presentation A 3-month-old infant was presented to us with history of poor feeding, respiratory distress and desaturations. The routine echocardiographic investigation initially confirmed the diagnosis of an atrial septal defect with dextrocardia. However, due to disproportionate severity of symptoms and congestive heart failure a cardiac computer tomography angiogram was done that revealed a rare finding of connection of pulmonary veins fused with the posterior atrium, but on the rightward side of the deviated atrial septum. Therefore, pulmonary veins entered a sinus that drains directly into the right atrial superior-posterior wall. During surgical repair, we found an area of absent pericardium in the diaphragmatic surface of the heart. The patient underwent total repair of the TAPVR and patch reconstruction of the pericardial defect. The patient is doing well at 6-month follow up. Conclusions The septum primum malposition defect resulting in TAPVR is a very rare congenital anomaly that can be rarely seen without any heterotaxy. The anomalous features including absent pericardium and dextrocardia were present in this patient have not been described previously with TAPVR. Therefore, we have hypothesized the embryological correlation of absent pericardium and cardiac malposition in such case. Transthoracic echocardiography with Doppler interrogation is a reliable method for diagnosing this condition. In case of suboptimal echocardiographic image due to cardiac position, unclear anatomy or unexplained symptoms, advanced imaging such as computer tomographic angiography or cardiac magnetic resonance imaging can be very helpful. Preoperative proper diagnosis of this anomaly facilitates successful surgical management with excellent outcome.

Relation between the size of patent foramen ovale and the volume of acute cerebral ischemic lesion in young patients with cryptogenic ischemic stroke

Background Patent foramen ovale (PFO) closure is superior to medical therapy alone to prevent stroke recurrence in selected patients. Small cortical infarcts and large right to left shunts seem to identify patients who will benefit most from closure. We aimed to study the correlation between the size of the PFO and the volume of cerebral ischemic lesions in young patients with cryptogenic ischemic stroke. Methods PFO dimensions and acute ischemic lesion volume of 20 patients, aged<55 years, were analyzed with transesophageal echocardiography and brain magnetic resonance imaging, respectively. The association between the volume of ischemic lesions with the length of PFO, maximum separation between septum primum and septum secundum, and the combination of the twos was explored. Results A direct statistically significant correlation was found between cerebral lesion volume and maximum separation of septum primum and septum secundum (p=0.047). Length of PFO showed a non-significant trend towards an inverse correlation with lesion volume (p=0.603). Multiple linear regression analysis showed that cerebral lesion volume was dependent directly on maximum separation and inversely on length of PFO (regression coeff. −0,837; p= 0.057; 2,536, p=0.006, respectively). Conclusions These data suggest that even small PFO might be pathogenetic in case of small cerebral infarcts and that large cerebral infarcts might be PFO related if the shunt is large. If confirmed, the combination of detailed characteristics of PFO with the volume of cerebral infarct could be integrated in a new score to select patients who would take real advantage from a percutaneous closure.

Multimodality imaging anatomy of interatrial septum and mitral annulus

The detailed anatomy of the interatrial septum (IAS) and mitral annulus (MA) as observed on cardiac magnetic resonance, computed tomography and two-dimensional/three-dimensional transthoracic and transesophageal echocardiography is reviewed. The IAS comprises of two components: the septum primum that is membrane-like forming the floor of the fossa ovalis (FO) and the septum secundum that is a muscular rim that surrounds the FO. The latter is an enfolding of atrial wall forming an interatrial groove. Named Waterston’s groove, it is filled with adipose tissue on the epicardial side. Thus, the safest area for transseptal puncture (TSP) is within the limits of the FO floor, which provides direct interatrial access. While crossing an intact septum is a well-established procedure, TSP is a more complex and time-consuming procedure in the presence of patent foramen ovalis, aneurysmal FO or atrial septal defect closure devices. MA comprises two distinctive segments: an anterior-straight and a posterior-curved segment. The posterior MA is a thin, discontinuous fibrous ‘string’, interspersed with adipose tissue, where four components converge: the atrial and ventricular musculature, epicardial adipose tissue and the leaflet’s hinge line. In parts of where this fibrous string is deficient or absent, the posterior leaflet is inserted directly on ventricular and atrial myocardium rendering the MA less robust and producing an ‘asymmetric’ dilation. The marked vulnerability of posterior MA to calcifications might be due to its insertion on the crest of ventricular myocardium being subject to friction injury due to the contraction and relaxation of LV.

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.

A severe right-to-left intracardiac shunt after NobleStitch failure: when a device is needed

Background Transcatheter closure of patent foramen ovale (PFO) has been demonstrated to be superior to medical therapy in stroke prevention in selected patients. Beyond traditional permanent metallic devices, NobleStitch EL, a suture-based system, has been developed as a potential alternative. Case summary A 50-year-old man underwent transcatheter closure of PFO with mild interatrial septal bulging and tunnel-like morphology with a NobleStitch device. A transthoracic echocardiography performed immediately after PFO closure showed residual shunt (RS), which persisted unchanged at staged controls, due to the inability of the delivery system to capture both the septum primum and the septum secundum. A second procedure was performed with the implantation of a Figulla Flex II 27/30 mm device, with no RS detectable at control echocardiography. Discussion The NobleStitch device is interesting in its concept, but several pitfalls may be encountered during its deployment. Opposite to permanent metallic devices, RSs after the procedure are not expected to decrease over time and should be managed with a different approach.

Recurrent Transient Ischemic Attack Followed By Stroke Due To Stretched Patent Foramen Ovale – A Rare Entity

A Patent Foramen Ovale (PFO) is not a true deficiency of atrial septal tissue but rather a potential space or separation between the septum primum and septum secundum located in the anterosuperior portion of the atrial septum. It is not considered a true Atrial Septal Defect (ASD), because no structural deficiency of the atrial septal tissue is present. We are describing a unique case of recurrent transient attacks followed by stroke associated with finding of a large stretched PFO on echocardiography.