Atrial Septum Research Articles

Atrial septum anatomy as a predictor of ischemic neurological episodes in patients with a patent foramen ovale.

The correlation between atrial septum anatomy and the risk of ischemic neurological events remains underexplored. This study aimed to examine both the functional and anatomical attributes of the atrial septum and identify predictors of stroke and/or transient ischemic attack (TIA) in patients diagnosed with patent foramen ovale (PFO). A total of 155 patients diagnosed with PFO, with a cardiological cause of neurological events, were enrolled. Transesophageal echocardiography was utilized to assess the anatomy of the PFO canal, size of the right-to-left shunt, thickness of the primary and secondary atrial septum, presence of atrial septum aneurysm, and anatomical structures of the right atrium. Regression analysis showed that factors such as female sex, hypercholesterolemia, PFO canal width, and a large right-to-left shunt were significantly associated with stroke and/or TIA. Receiver operating characteristic analysis indicated that the width of the PFO canal holds a relatively weak, although significant predictive, value for ischemic neurological episodes (area under the curve = 0.7; P = 0.002). A PFO canal width of 4 mm was associated with 70% sensitivity and 55% specificity for predicting stroke and/or TIA. The atrial septum's anatomy, especially the dimensions of the PFO canal and the magnitude of the right-to-left shunt, combined with specific demographic and clinical factors, are linked to ischemic neurological incidents in PFO patients.

Inter-atrial septal balloon dilation to facilitate intracardiac echocardiography guided left atrial appendage occlusion.

Percutaneous left atrial appendage occlusion (LAAO) is traditionally performed under general anesthesia with trans-esophageal echocardiography guidance. Intracardiac echo (ICE)-guided LAAO closure is increasing in clinical use. The ICE catheter is crossed into LA via interatrial septum (IAS) after the septum is dilated with LAAO delivery sheath. This step can be time-consuming and requires significant ICE catheter manipulation, which increases the risk of cardiac perforation. Pre-emptive septal balloon dilation can potentially help with ICE advancement in the LA. We sought to evaluate the effect of pre-dilation of the IAS with an 8 mm balloon on the ease of crossing the ICE catheter, fluoroscopy time for crossing, and overall procedure time. The Piedmont LAAO registry was used to identify consecutive patients who underwent LAAO. The initial 25 patients in whom balloon dilation of the IAS was performed served as the experimental cohort, and the 25 consecutive patients before that in whom balloon dilation was not performed served as controls. In the experimental group, after a trans-septal puncture, the sheath was retracted to the right atrium with a guidewire still in the LA. An 8 × 40 mm Evercoss™ over the wire balloon was inflated across the IAS. The ICE catheter was then crossed into the LA using the fluoroscopic landmark of the guide wire and the ICE imaging. The sheath was then advanced along the ICE catheter via the transseptal puncture (TSP) and the procedure continued. Follow-up compputed tomography imaging was obtained at 4-8 weeks. Each group consisted of 25 patients. There were no significant differences in baseline characteristics. All procedures were performed successfully under conscious sedation and ICE guidance. There was a significant reduction in the overall procedure time, fluoroscopy time, and time for transseptal puncture to ICE in LA. There was no difference in the size of the acute residual interatrial shunt, as measured via ICE, or the size and presence of iatrogenic ASD at follow-up. Balloon dilation of TSP is safe and is associated with increased efficiency in ICE-guided LAAO procedures.

Echocardiographic features and outcomes of fetuses with isolated restrictive foramen ovale or redundant foramen ovale flap using atrial septum excursion index.

This study was designed to investigate the application value of the atrial septum excursion index (ASEI) in fetuses with isolated restrictive foramen ovale (RFO) or redundant foramen ovale flap (RFOF) and the outcomes of these fetuses. This was a retrospective study. Healthy pregnant women who were examined by antenatal fetal echocardiography from January 1, 2019 to December 31, 2021, at Sir Run Run Shaw Hospital were enrolled. One hundred seventy-seven (177) fetuses were categorized into three groups by diagnosis: (1) RFOF (n = 33), (2) RFO (n = 21), and (3) normal (n = 123). Fetal echocardiographic features and postnatal outcomes were collected. The median ASEIs were 0.50 (range, 0.41-0.65) in the control group, 0.76 (range, 0.67-0.88) in the RFOF group and 0.31 (range, 0.14-0.35) in the RFO group, and the differences were significant (p < 0.001). The ratios of right atrium/left atrium, right ventricle/left ventricle, and pulmonary artery diameter to aorta diameter (PA/AO) and the pulmonary annulus Z-scores were greater in fetuses with RFOF and RFO than in the controls (p < 0.05). Twenty-seven of 33 fetuses (87.9%) with RFOF and 19 of 21 fetuses (90.5%) with RFO had good outcomes after birth. The ASEI may be a new tool for quantitatively assessing the mobility of foramen ovale flaps in fetuses with isolated RFOF or RFO.

КЛИНИЧЕСКИЙ СЛУЧАЙ ВРОЖДЕННОГО ГИПОТИРЕОЗА

The article presents a clinical case of congenital hypothyroidism. A child (girl) was born from a mother who was diag-nosed with hypothyroidism. The child is from dichorionic diamniotic twins. During intrauterine development, growth retardation of the second fetus was observed. The child was born by Caesarean section, with low body weight; the condition after birth was severe due to respiratory distress syndrome and prematurity. According to the result of neonatal screening, the level of thyroid-stimulating hormone was 305.75 µIU/ml, and ultrasound examination revealed thyroid gland agenesis. A diagnosis of hypothyroidism was made. A slight valvular stenosis of the pulmonary artery, an aneurysm of the interatrial septum with a defect, an incomplete vascularization of the retina of both eyes, and an inguinal hernia were revealed. The presence of dysembryogenesis stigma (hernia, aneurysm of the interatrial septum, low ears, macroglossia, moderate marbled cyanosis, flat-bridged nose, moderate hypotension) indicates the hereditary nature of the disorders. A theoretical analysis of possible candidate genes for the development of hypothyroidism was carried out. It was shown that the TSHR, NKX2-5, THRA, TSHB, TRHR, TBL1X, IRS4, PAX8, FOXE1, NKX2-1 genes are responsible for congenital hypothyroidism. It is noted that these genes are the regulators of the development and maturation of the thyroid gland or encode thyroid hormone receptors. Conclusion. For better understanding the etiopathogenetic mechanisms of the formation of congenital hypothyroid-ism, it is necessary to consider the possibility of confirmatory DNA diagnostics.

Epicardial fat and left atrial appendage thrombosis in patients with persistent atrial fibrillation

BACKGROUND: Excessive deposition of the epicardial adipose tissue (EAT) plays a role in the development of a number of cardiovascular diseases, including ischemic stroke. As more than half of strokes in patients with atrial fibrillation (AF) are cardioembolic, and the source of thromboembolic complications is the left atrial appendage (LAA), it can be assumed that excess EAT contributes to the development of LAA thrombus. The literature does not present the results of a study of the relationship between the amount of EAT and LAA thrombus in patients with AF, which makes it relevant to study this issue.AIM: to study the effect of EAТ on LAA thrombosis and the emptying flow velocity from the LAA in patients with persistent AF.MATERIALS AND METHODS: The patients with persistent AF underwent transesophageal and transthoracic echocardiography before the planned cardioversion. The transesophageal echocardiography measured the emptying flow velocity from the LAA, and the thickness of the interatrial septum and the left lateral ridge, the average value of which was used to estimate the amount of left atrial EAT. The thickness of the anterior wall of the right ventricular EAT was measured by transthoracic echocardiography.RESULTS: The LAA thrombus was detected in 42 (8.6%) patients of 486 patients with persistent AF (age 64.0 [59.0; 70.0] years, men 58.0%). Patients with thrombus had greater thickness of the left atrial EAT (9.30 [9.05; 9.55] vs. 7.70 [7.03; 8.28] mm, p&lt;0.001) and of the right ventricular EAT (8.05 [7, 90; 8.90] versus 7.80 [7.20; 8.40] mm, p = 0.001), but the emptying flow velocity from the LAA is lower (20.0 [14.0; 26.0] versus 32.0 [26.0; 39.0] cm/s, p&lt;0.001). Area under the receiver operator characteristic curve for the thickness of the left atrial EAT, as a predictor of the LAA thrombosis, was significantly larger than for the thickness of the right ventricular EAT: 0.947 (0.923–0.965) versus 0.661 (0.617–0.703), p&lt;0.001. The thickness of the left atrial EAT more than 8.6 mm increases the chances of LAA thrombosis by 70.1 (24.1–204.2) times. Analysis of multiple linear regression did not reveal an independent effect of the thickness of the left atrial EAT (b = -0.0951±0.6163, p = 0.877) and of the right ventricular EAT (b = 0.6764±0.4383, p = 0.124) on the emptying flow velocity from the LAA.CONCLUSION: The increased of the thickness of EAT increases the chances of developing LAA thrombosis in patients with persistent AF, but does not affect on the emptying flow velocity from the LAA.

Right disc thrombosis of the new Gore Cardioform ASD Occluder.

The GCA is a well performing device in terms of efficacy despite complex anatomies (aortic rim <5 mm and ASD diameter >17 mm) with a good safety profile. To evaluate atrial septal defect (ASD) features impacting on right disc device thrombosis in patients who underwent Gore Cardioform ASD Occluder (GCA) implantation. A total of 44 consecutive patients undergoing percutaneous ASD with GCA device from January 2020 to September 2022 at our tertiary care Center were evaluated. The minimum follow-up was 6 months. The patients were stratified in two groups according to a cut-off value of ASD diameter equal to 20 mm at sizing balloon, derived from ROC analysis (AUC = 0.894; p = 0.024). Baseline characteristics were comparable between groups in terms of age, sex, weight, height, and interatrial septum dimensions. Patients with ASD > 20 mm (n = 9) had a higher ASD/device dimension ratio, both at echocardiography (p = 0.009) and at sizing balloon (p = 0.001), longer fluoroscopic time (p = 0.022), and higher incidence of device thrombosis (0.006). Right disc thrombosis was observed in three patients of the ASD > 20 mm group, always in the inferior portion of the right disc. On univariate analysis, ASD diameter at sizing balloon (OR 1.360; p = 0.036) was the only positive predictor of device thrombosis. Right disc thrombosis of the GCA device may be under-recognized at follow-up, hence deserving clinical attention, especially in those patients with larger ASD diameters.

Ignored Role of Paroxysmal Atrial Fibrillation in the Pathophysiology of Cryptogenic Stroke in Patients with Patent Foramen Ovale and Atrial Septal Aneurysm.

The association between cryptogenic stroke (CS) and patent foramen ovale (PFO) with or without atrial septal aneurysm (ASA) has been a debate for decades in terms of pathophysiologic processes and clinical courses. This issue has become more interesting and complex, because of the concerns associating the CS with so-called normal variant pathologies of interatrial septum, namely ASA and PFO. While there is an anatomical pathology in the interatrial septum, namely PFO and ASA, the embolic source of stroke is not clearly defined. Moreover, in patients with PFO and CS, the risk of recurrent stroke has also been associated with other PFOunrelated factors, such as hyperlipidemia, body mass index, diabetes mellitus, and hypertension, leading to the difficulty in understanding the pathophysiologic mechanism of CS in patients with PFO and/or ASA. Theoretically, the embolic source of cryptogenic stroke in which PFO and/or ASA has been involved can be categorized into three different anatomical locations, namely PFO tissue and/or ASA tissue itself, right or left atrial chambers, and venous vascular territory distal to the right atrium, i.e., inferior vena cava and lower extremity venous system. However, the possible role of paroxysmal atrial fibrillation associated with PFO and/or ASA as a source of cryptogenic stroke has never been mentioned clearly in the literature. This review aims to explain the association of cryptogenic stroke with PFO and/or ASA in a comprehensive manner, including anatomical, clinical, and mechanistic aspects. The potential role of paroxysmal atrial fibrillation and its contribution to clinical course have been also discussed in a hypothetical manner to elucidate the pathophysiology of CS and support further treatment modalities.

Associations of the left atrial epicardial fat thickness with the thrombosis prevalence and left atrial appendage flow velocity in patients with persistent non-valvular atrial fibrillation

Aim. To study the associations of the left atrial epicardial fat (LAEF) thickness with the thrombosis prevalence and left atrial appendage (LAA) flow velocity in patients with persistent non-valvular atrial fibrillation (AF).Material and methods. Transesophageal echocardiography in 475 patients with persistent non-valvular AF (men 58,9%, age 64,0 (58,3-70,0) years) assessed LAA flow velocity, interatrial septum and left lateral ridge thickness. Their average thickness was used to estimate the LAEF volume.Results. LAA thrombus was detected in 42 (8,8%) patients. LAA flow velocity without thrombus was 32,0 (26,0-39,0) cm/s, with thrombus — 20,0 (14,0-25,8) cm/s (p&lt;0,0001). Depending on the LAEF thickness, patients were divided into 3 tertile groups: group 1 (n=168) — 5,6-7,4 mm, group 2 (n=154) — 7,45-8,2 mm, group 3 (n=153) — 8,25-10,9 mm. In group 1, no thrombus was detected, in group 2, thrombus was detected in 2 (1,3%) patients, in group 3 — in 40 (26,0%) patients (p&lt;0,0001). In the absence of LAA thrombus, flow velocity in the selected groups did not differ (32,0 (26,0-39,0) cm/s, 31,0 (26,0-7,8) cm/s and 31,5 (25,0-40,0) cm/s, (p=0,9514)).Conclusion. EFL thickness, calculated as the average of interatrial septum and left lateral ridge thickness, can be used to study the relationship between epicardial obesity and LAA thrombosis in patients with AF. In patients with persistent non-valvular AF with a LAEF thickness &gt;8,2 mm, LAA thrombosis occurs more than 40 times more often than in patients with a lower LAEF thickness. The influence of LAEF thickness on LAA flow velocity was not revealed in the pre­sent study.

Staged repair of borderline hypoplastic heart disease with early biventricular conversion

ObjectiveIn select patients with borderline ventricular hypoplasia, we adopted a strategy of initial single-ventricle palliation followed by staged or direct biventricular conversion by 2 years of age. MethodsBetween 2018 and 2023, 14 newborns with borderline hypoplastic heart disease deemed high risk for primary biventricular repair underwent palliative procedures as a neonate/infant, followed by staged or direct biventricular conversion. ResultsOf the 14 patients, 6 had borderline left ventricles and 8 had borderline right ventricles. Index neonatal operations were performed in 12 patients and included the Norwood operation (n = 5), pulmonary artery band (n = 3), ductal stent (n = 3), and hybrid Norwood (n = 1). Five patients underwent direct biventricular conversion, and the remaining 9 patients underwent staged ventricular recruitment operations at a mean age of 6 months (range, 3-11 months). Ventricular recruitment operations included atrial septation with or without ventricular rehabilitation, atrioventricular valve repair, or outflow tract operations. At a mean duration of 8 months (range, 4-10 months) after ventricular recruitment, there was a significant increase in chamber volume, aortic valve, and mitral valve size in patients with borderline left ventricles, and a normalization of the right ventricle:left ventricle end-diastolic volume ratio in patients with borderline right ventricles. To date, 13 of 14 patients have undergone successful biventricular conversion at a mean age of 16 months (range, 4-31 months). ConclusionsIn select newborns with borderline hypoplastic heart disease, single-ventricle palliation followed by staged or direct biventricular conversion may increase infant survival while allowing for early attainment of a biventricular circulation.

Papillary fibroelastoma originating from the atrial septum touching the mitral valve leading to infective endocarditis: a case report

BackgroundCardiac papillary fibroelastoma is a rare benign tumor, which is often mistaken for a vegetation. Predominantly asymptomatic, it can cause life-threatening complications. Although rare, mobile papillary fibroelastoma movement between affected valves may hamper valve closure and damage the valve, leading to valvular regurgitation. Endothelial damage increases the risk of developing infective endocarditis. We report a rare case of a highly mobile papillary fibroelastoma originating from the atrial septum touching the mitral valve, leading to mitral regurgitation and, eventually, infective endocarditis.Case presentationA 26-year-old woman with suspected infective endocarditis was referred to us from a previous hospital after having experienced intermittent fever for a month. Before the fever, she had been experiencing exertional dyspnea. In addition, she had undergone a cesarean section two weeks before this admission. A transthoracic echocardiogram showed a mobile mass originating from the atrial septum touching the mitral valve with severe mitral regurgitation. Computed tomography revealed an occluded right profunda femoris artery with an embolus. Infective endocarditis associated with a mobile vegetation with high embolic risk was diagnosed, and urgent surgery was performed. Following the surgery, examinations revealed papillary fibroelastoma originating from the atrial septum and infective endocarditis of the mitral valve. The histopathological examination confirmed that a mass initially thought to be a mobile vegetation was a papillary fibroelastoma. The postoperative course was uneventful except for pericarditis. There has been no recurrence of infective endocarditis or papillary fibroelastoma.ConclusionsThe highly mobile papillary fibroelastoma was thought to have caused both chronic mitral regurgitation and infective endocarditis. Mobile papillary fibroelastomas can cause endothelial damage to nearby valves and predispose patients to infective endocarditis.

Quantitative analysis of the impact of respiratory state on the heartbeat-induced movements of the heart and its substructures

PurposeThis study seeks to examine the influence of the heartbeat on the position, volume, and shape of the heart and its substructures during various breathing states. The findings of this study will serve as a valuable reference for dose-volume evaluation of the heart and its substructures in radiotherapy for treating thoracic tumors.MethodsTwenty-three healthy volunteers were enrolled in this study, and cine four-dimensional magnetic resonance images were acquired during periods of end-inspiration breath holding (EIBH), end-expiration breath holding (EEBH), and deep end-inspiration breath holding (DIBH). The MR images were used to delineate the heart and its substructures, including the heart, pericardium, left ventricle (LV), left ventricular myocardium, right ventricle (RV), right ventricular myocardium (RVM), ventricular septum (VS), atrial septum (AS), proximal and middle portions of the left anterior descending branch (pmLAD), and proximal portion of the left circumflex coronary branch (pLCX). The changes in each structure with heartbeat were compared among different respiratory states.ResultsCompared with EIBH, EEBH increased the volume of the heart and its substructures by 0.25–3.66%, while the average Dice similarity coefficient (DSC) increased by − 0.25 to 8.7%; however, the differences were not statistically significant. Conversely, the VS decreased by 0.89 mm in the left–right (LR) direction, and the displacement of the RV in the anterior–posterior (AP) direction significantly decreased by 0.76 mm (p < 0.05). Compared with EIBH and EEBH, the average volume of the heart and its substructures decreased by 3.08–17.57% and 4.09–20.43%, respectively, during DIBH. Accordingly, statistically significant differences (p < 0.05) were observed in the volume of the heart, pericardium, LV, RV, RVM, and AS. The average DSC increased by 0–37.04% and − 2.6 to 32.14%, respectively, with statistically significant differences (p < 0.05) found in the right ventricular myocardium and interatrial septum. Furthermore, the displacements under DIBH decreased in the three directions (i.e.,− 1.73 to 3.47 mm and − 0.36 to 2.51 mm). In this regard, the AP displacement of the heart, LV, RV, RVM, LR direction, LV, RV, and AS showed statistically significant differences (p < 0.05). The Hausdorff distance (HD) of the heart and its substructures under the three breathing states are all greater than 11 mm.ConclusionThe variations in the displacement and shape alterations of the heart and its substructures during cardiac motion under various respiratory states are significant. When assessing the dose-volume index of the heart and its substructures during radiotherapy for thoracic tumors, it is essential to account for the combined impacts of cardiac motion and respiration.

Aortic root rotation: morphological analysis of the aortic root with three-dimensional computed tomography.

The aortic root (AoR) rotation and its spatial morphology at the base of the heart were postulated but not described in every detail. AoR rotation modalities may play an important role in decision-making during AoR surgery and its outcome. The aim was to provide a detailed spatial anatomy of the AoR rotation and its relation to the vital surrounding structure. The AoR rotation and its relation to the surrounding structure were assessed in 104 patients with tricuspid aortic valve. The interatrial septum was chosen as a reference to describe AoR rotation that marked the midline of the heart base as a landmark for the AoR rotation direction. Intermediate, clockwise and counterclockwise AoR rotations were defined based on the mentioned reference structures. The AoR rotation was successfully assessed in 104 patients undergoing ascending aorta and or AoR intervention by multidetector row computed tomography. AoR was positioned normally in 53.8% of cases (n = 56) and rotated counterclockwise in 5.8% (n = 6) and clockwise in 40.4% (n = 42) of cases. In clockwise AoR rotation, the right coronary sinus was positioned in proximity to the right atrium and of the tricuspid valve, whereas in a counterclockwise rotation, the noncoronary sinus was placed over the tricuspid valve just over the membranous septum. The AoR's rotation can be diagnosed using multidetector row computed tomography. Understanding the anatomy of the aortic valve related to rotational position helps guide surgical decision-making in performing AoR reconstruction.

Stent Implantation Across the Atrial Flow Regulator Device.

The Atrial Flow Regulator (AFR) is a self-expandable double-disc device with a central fenestration, intended to maintain a calibrated communication across the interatrial septum. We reported for the first time a stent implantation across an AFR device in an adolescent born with complex congenital heart disease with duct-dependent systemic circulation and severe combined pulmonary hypertension.

An Unusual Presentation of Partial Atrioventricular Canal Defect in an Elderly Woman

A partial atrioventricular canal defect (PAVCD) is a form of endocardial cushion defect. It’s a rare congenital cardiac malformation, few reported patients have survived into the seventh decade of life. A 71-year-old female with a history of diabetes and hypertension was admitted for heart failure (HF) symptoms. Transthoracic echocardiography revealed a left to right shunt in the basal portion of the interatrial septum, 19mm ostium primum atrial septal defect (ASD), a mitral valve cleft, and severe mitral valve regurgitation. PAVCD consists of an ostium primum ASD and the dividing of the common atrioventricular (AV) valve into 2 separate AV orifices, resulting in a so-called cleft in the mitral valve. The ventricular septum is intact. Echocardiography is the key tool for diagnosis and anatomic classification. Surgical repair is recommended in adults with primum ASDs causing impaired functional capacity, right atrial or right ventricular enlargement, and left-to-right shunt without cyanosis, as long as systolic pulmonary artery pressures are lower than 50% of systemic pressures. Reconstructive surgery includes, in addition to the closure of the interatrial septum, a suturing of the mitral cleft. The estimated mean age at death of the patients with ostium primum ASD is about 40 years. The objective of this clinical case is to highlight the good clinical tolerance of atrial shunts and the anatomical particularities in the PAVCD.

Hematoma of the interatrial septum after surgery for a giant aneurysm of the sinus of Valsalva.

Hematoma of the interatrial septum after surgery for a giant aneurysm of the sinus of Valsalva.

Case report: Para Hisian Atrial Tachycardia

Case report: Para Hisian Atrial Tachycardia

Video assisted thorascopic assisted correction of left partial anomalous pulmonary venous connection: one case report

IntroductionThe left partial anomalous pulmonary vein connection is a rare congenital heart disease, especially with intact atrial septum. Now we reported a case of the left superior pulmonary vein drainage to left innominate vein through a vertical vein, and corrected with video assisted thoracoscopy.Case presentationA-59-years old man diagnosed left anomalous partial pulmonary vein connection with presentation of short breathiness and palpation, and diagnosed with computer tomography pulmonary angiography. The operation was carried out under video assisted thoracoscopy with one manipulation incision and one observational incision, the vertical vein was dissected and anastomosis with left atrial appendage. The patients recovered smoothly and postoperative CTPA showed anastomosis ostium was unobstructed.ConclusionThe left lateral thoracotomy and video assisted thoracoscopic surgery is a feasible for correction of left PAPVC with intact interatrial septum without using CPB.

Abnormal aortic origin of coronary arteries

The anomalous aortic origin of the coronary arteries has an estimated prevalence of 0.02-5.7%. It can be associated with sudden death when it has an interarterial or intramural pathway or be damaged during interventions on the mitral, pulmonary and/or aortic annulus or percutaneous closure of an interatrial septal defect. To identify these patients by imaging techniques such as transthoracic color Doppler echocardiography (TTE), computed tomography (CT) multislice angiography or coronary angiography. The imaging techniques used for the detection of coronary anomalies were TTE, multislice coronary angiography or coronary angiography according to what is generally accepted. Fifteen patients were identified; in 12 of them the suspicion was due to TTE and in the remaining 3, CT multislice angiography was diagnostic. The circumflex artery was the coronary artery most involved, associated or not with another coronary anomaly (12/15 patients) and in the other three cases, the anomalous coronary artery had an interarterial course, with the right coronary arteries and the anterior descending coronary arteries being involved. The under diagnosis by TTE of coronary artery abnormalities may be due to the difficulty of visualization that is accentuated with age. Their detection is crucial because they can both, lead to sudden death associated with an intramural and/or interarterial pathway and complicate an interventional procedure on the interatrial septum or within the mitral, pulmonary and/or aortic rings.

Experimental study of the bilateral asymmetric single-rivet occluder device for transcatheter patent foramen ovale closure with reserved interatrial septal puncture area.

To evaluate a noval bilateral asymmetric single-rivet occluder with reserved interatrial septal puncture area for treating patent foramen ovale (PFO). The study established a pig model of patent foramen ovale (PFO) by puncturing the oval fossa and then performing high-pressure balloon dilation. A specially designed bilateral asymmetric occluder for the reserved interatrial septal puncture area was then. used to close the PFO through catheter-based intervention. The pigs were kept for 3 months before undergoing a second catheter-based intervention, involving interatrial septal puncture using a newly developed occluder in the reserved interatrial septal puncture area. During 6 months, the experimental pigs underwent assessment using digital subtraction angiography (DSA), echocardiography, and histological evaluation. A patent foramen ovale (PFO) model was successfully established in 6 pigs using the puncture atrial septum high-pressure balloon dilation method. The diameter of the unclosed PFO was measured (3.56 ± 0.25 mm). Using the newly developed occluder device, all 6 pigs with unclosed PFO underwent successful catheter-based closure surgeries, with intraoperative and postoperative transesophageal echocardiography showing excellent device positioning and complete closure without residual shunting. After 3 months of implantation, the catheter-based interatrial septal puncture was performed through the reserved interatrial septal puncture area, and all procedures were successful. Immediately following euthanasia, a histological examination revealed intact and undamaged occluder devices with visible puncture holes in the reserved interatrial septal puncture area. No fracture of the nitinol wire was observed, and the surface of the occluder device showed coverage of endothelial and connective tissues. Utilizing a bilateral asymmetric single-rivet occluder device implanted through the reserved interatrial septal puncture area has proven effective in closing PFO. After implantation, the occluder device allows subsequent interatrial septal puncture procedures through the reserved area. The novel occluder device demonstrated excellent closure performance, biocompatibility, and puncturability in the experiment. This indicates the feasibility of conducting further catheter-based interventions on the interatrial septum.

Trisomy 21 Alters Cell Proliferation and Migration of iPSC-Derived Cardiomyocytes on Type VI Collagen.

Individuals with Down syndrome (DS) are 2000 times more likely to develop a congenital heart defect (CHD) than the typical population Freeman et al. in Am J Med Genet 80:213-217 (1998). The majority of CHDs in individuals with DS characteristically involve the atrioventricular (AV) canal, including the valves and the atrial or ventricular septum. Type VI collagen (COLVI) is the primary structural component in the developing septa and endocardial cushions, with two of the three genes encoding for COLVI located on human chromosome 21 and upregulated in Down syndrome (von Kaisenberg et al. in Obstet Gynecol 91:319-323, 1998; Gittenberger-De Groot et al. in Anatom Rec Part A 275:1109-1116, 2023). To investigate the effect of COLVI dosage on cardiomyocytes with trisomy 21, induced pluripotent stem cells (iPSC) from individuals with DS and age- and sex-matched controls were differentiated into cardiomyocytes (iPSC-CM) and plated on varying concentrations of COLVI. Real time quantitative PCR showed decreased expression of cardiac-specific genes of DS iPSC-CM lines compared to control iPSC-CM. As expected, DS iPSC-CM had increased expression of genes on chromosome 21, including COL6A1, COL6A2, as well as genes not located on chromosome 21, namely COL6A3, HAS2 and HYAL2. We found that higher concentrations of COLVI result in decreased proliferation and migration of DS iPSC-CM, but not control iPSC-CM. These results suggest that the increased expression of COLVI in DS may result in lower migration-driven elongation of endocardial cushions stemming from lower cell proliferation and migration, possibly contributing to the high incidence of CHD in the DS population. The online version contains supplementary material available at 10.1007/s12195-023-00791-x.