Chiari Network Research Articles

Anatomical Significance of the Patent Foramen Ovale by Real-Time 3D TEE in Cryptogenic Stroke and Migraine.

The transesophageal echocardiogram (TEE) is the standard imaging modality for confirming the presence or absence of patent foramen ovale. PFO is a flap valve depending on the pressure change between the left and right atrium, which can help determine whether to open. 3D-TEE was shown to optimize the visualization of PFO. There is a causal association between PFO and unexplained stroke. It seems that 3D-TEE can present a high-risk PFO morphological feature, which seems to show more than just being easier to open. In total, 134 consecutive patients with cryptogenic stroke or migraine who had suspected PFO and underwent c-TCD, TTE, and c-TEE were included in this study. TEE confirmed the PFO. The right-to-left shunt (RLS) grade of PFO at rest and abdominal compression Valsalva maneuver was detected by c-TEE. The long diameter of FO (1.74 ± 0.3vs. 1.60 ± 0.4, p = 0.039), the short diameter of FO (1.12 ± 0.3vs. 1.00 ± 0.3, p = 0.036), perimeter of FO (4.62 ± 0.7vs. 4.22 ± 1.0, p = 0.026), and area (1.80 ± 0.8vs. 1.35 ± 0.8, p = 0.05) of the FO were significantly larger in the larger RLS group. In group of CS, a larger proportion of Eustachian valve or a Chiari's network (14.3%vs. 3.5%, p = 0.036), a larger proportion of in the left funnelform (55.1%vs. 16.3%, p < 0.001), a longer length of the PFO tunnel (13.4 ± 4.4vs. 7.8 ± 2.5, p < 0.001), a lower IVC-PFO angle (16.4 ± 3.4vs. 20.3 ± 7.7, p = 0.001), a higher proportion of LA multiple exits of the tunnel (46.9%vs. 14.3%, p < 0.001). Multivariate regression analysis showed that male gender (HR: 4.026, 95% CI: 0.883-18.361, p = 0.072), age (HR: 1.076, 95% CI: 1.002-1.155, p = 0.045), the left funnelform (HR: 7.299, 95% CI: 1.585-33.618, p = 0.011), a longer length of the PFO tunnel (HR: 1.843, 95% CI: 1.404-2.418, p < 0.001) and multiple exits of the tunnel of LA (HR: 8.544, 95% CI: 1.595-45.754, p = 0.012) increased the risk of cerebral infarction. The cut-off value calculated by ROC for the diagnosis of high-risk PFO was that the length of the PFO tunnel was 12mm and the left funnelform combined with multiple exits of the left atrial (sensitivity was 92%, specificity was 90%). The area under the curve of the combined index versus PoPE score (0.932 vs. 0.736) relative to the RoPE score was statistically significant. TEE has shown outstanding advantages in displaying the specific morphological characteristics of PFO. The left funnelform, a longer length of the PFO tunnel, and multiple exits of the tunnel of LA are associated with an increasing risk of CS in anatomical PFO respect.

Characteristics of patients diagnosed for cardiac cause of ischemic neurological events and prescreened with a transcranial Doppler examination.

Screening for patent foramen ovale (PFO) in patients with ischemic neurological events is becoming more common. This study aimed to evaluate clinical characteristics and atrial septum anatomy in relation to age and presence of PFO, as well as factors associated with a history of stroke in patients assessed for cardiac causes of ischemic neurological events. A total of 817 patients with a history of neurological episodes (stroke, transient ischemic attack [TIA], or migraine) were prescreened using transcranial Doppler ultrasound. Transesophageal contrast echocardiography (TEE) was employed to confirm PFO and assess the anatomy of the atrial septum and right atrium. Among the patients, 28% had ischemic stroke, 31% had TIA, and 49% had migraines. PFO was confirmed in 79% of the patients. Regardless of the analyzed age group, PFO was associated with higher prevalence of TIA, migraine and syncope history, atrial septal aneurysm (ASA), and Chiari network. There were fewer women in the PFO group, but only in the population aged 45 years or under. Patient age, male sex, typical cardiovascular risk factors, and the presence of ASA were associated with a history of stroke. In patients with ischemic neurological events who were prescreened for PFO, confirmation of PFO on TEE was associated with a higher prevalence of TIA, migraine, syncope, Chiari network, and ASA. Advanced age, typical cardiovascular risk factors, and ASA were associated with stroke history in the study population.

Guidewire entrapment in the Chiari network during the insertion of a hemodialysis catheter: a case report

BackgroundThe Chiari network, a remnant of fetal anatomy, consists of a mesh-like structure within the right atrium. With advancements in cardiac interventions, complications associated with the Chiari network have increasingly been reported. However, there are few reports about guidewire or catheter entrapment in the Chiari network during the insertion of a dialysis catheter.Case presentationA 46-year-old male with end-stage renal disease was hospitalized and underwent a digital subtraction angiography-assisted catheterization of the right internal jugular vein tunnel-cuffed dialysis catheter. When the guide wire entered a depth of about 20 cm, it was difficult to advance, manifested as resistance when twisting the guide wire and inability to enter the inferior vena cava. After the peelable sheath was inserted, it was difficult to pull out the guide wire. After repeated attempts to rotate the guide wire, the guide wire was finally pulled out. A fibrous tissue was wrapped around the tip of the guide wire. Its length was 6 cm, with a smooth surface and tough texture. We considered that the tissue we pulled out was most likely a part of a Chiari network.ConclusionsThis case highlights the potential for the Chiari network to complicate surgical procedures, including difficulty with guidewire and catheter manipulation. Attention should be paid to Chiari networks. Echocardiography can be used to identify the Chiari network. During the surgery, forcefully pulling out a stuck guidewire is not suggested, to avoid the risk of tearing the atrial wall and causing pericardial tamponade. An urgent consultation with ultrasound doctors and cardiac surgeons might be helpful in such cases.

Morphological Features of Patent Foramen Ovale Compared Between Older and Young Patients With Cryptogenic Ischemic Stroke.

The morphology of a patent foramen ovale (PFO) with a high-risk for cryptogenic ischemic stroke (CS) is an important factor in the selection of patients for transcatheter closure, but the morphological features of PFO in older patients with a history of CS are less known because the most data are obtained from younger patients. The study included 169 patients who had a history of CS and PFO. The prevalence of high-risk morphologies of PFO assessed by transesophageal echocardiography was compared between patients aged ≥60 years and patients aged <60 years. We also assessed the presence of septal malalignment of PFO on the aortic wall. The probability of CS due to PFO was evaluated using the PFO-Associated Stroke Causal Likelihood classification system. Patients aged ≥60 years had a significantly higher prevalence of atrial septal aneurysm than patients aged <60 years. The prevalence of large right-to-left shunt, long-tunnel of PFO, or Eustachian valve or Chiari's network was similar between patients aged ≥60 years and <60 years. Septal malalignment was observed more frequently in patients aged ≥60 years than in those <60 years old. Nearly 90% of patients aged ≥60 years were classified as 'possible' in the PFO-Associated Stroke Causal Likelihood classification system. High-risk morphologies of PFO are common in older patients with a history of CS, as well as in younger patients.

Co-occurrence of patent foramen ovale and Chiari network in a diabetic patient.

The coexistence of congenital cardiovascular anomalies provides valuable insights into the intricate nature of human cardiac anatomy and its potential interactions with underlying health conditions. This case report presents an autopsy analysis of a diabetic patient manifesting both a patent foramen ovale and a Chiari network. A 26-year-old male with a history of type 2 diabetes mellitus was admitted with post cardiac arrest. He died despite resuscitative efforts. Autopsy revealed notable findings including a patent foramen ovale and a Chiari network. Post-mortem biochemical markers indicated elevated HbA1c level and hyperglycaemia. The absence of cryptogenic strokes or paradoxical embolism prompted exploration into potential relationships between these anomalies and metabolic disturbances, and prompts a discussion about whether the observed anatomical variations could potentially serve as risk factors contributing to the patient's death due to complications of diabetes. The co-occurrence of a patent foramen ovale and a Chiari network within a diabetic patient, accompanied by elevated HbA1c level and hyperglycaemia, offers a unique perspective on the convergence of congenital cardiovascular variation and metabolic health. The juxtaposition of these anomalies with biochemical markers underscores the intricate interplay between cardiac morphology and metabolic conditions.

The Covert Impact of Chiari Network and Eustachian Valves on Stroke: A Scoping Review and Meta-Analysis.

The role of Chiari network (CN) and Eustachian valves (EVs) in cardioembolic strokes is still unclear. There is inconsistency in the literature regarding clinical approach to these lesions to reduce stroke risk. We aimed to describe clinical presentation, neuroimaging and cardioimaging features, as well as management approaches for CN and EV in stroke context. A systemic search was carried out using PubMed and Web of Science following PRISMA guidelines, Supplemental Digital Content 1 ( http://links.lww.com/NRL/A123 ). We retrieved 4 case-control studies, 2 cross sectional studies as well 8 case reports, with a total of 883 patients with a mean age of 44.6 years (±13.8). The combined prevalence of EV/CN in stroke-related patent foramen ovale (PFO) patients was 50% (95% CI: 31-68). With isolated prevalence for EV and CN of 43% (95% CI: 25-63), 18% (95% CI: 12-25), respectively. Patients with history of stroke had higher prevalence of EV/CN compared with controls odds ratio=2.45 (95% CI: 1.2-5, P <0.01). All case-control and cross-sectional studies defined EV/CN by transesophageal echocardiography or intracardiac cardiography. In the 8 case reports, 7 cases were diagnosed by transesophageal echocardiography, while only 1 case was diagnosed postmortem. EV/CN are relatively common findings in stroke patients with PFO. While it appears that presence of EV/CN with a PFO increases the risk of cardioembolic stroke, they remain underrecognized. EV/CN should be considered as high-risk PFO features. There is a scarcity of research emphasizing their role in clinical decision making, especially PFO closure and antithrombotic therapy choice.

Chiari Network and Eustachian Valves in PFO-related Stroke; Incidental or Pathogenic Finding? (P9-5.022)

Chiari Network and Eustachian Valves in PFO-related Stroke; Incidental or Pathogenic Finding? (P9-5.022)

An Unusual Chiari Network: Potential Risk in Cardiac Interventional Procedures

The Chiari network, seen in the right atrium, is a remnant of the right valve of the sinus venosus, resulting due to the incomplete regression of the valve during development. It is found in approximately in 1.5 to 3% individuals. During routine dissection for the first year M.B.B.S. students, we came across a cadaveric heart that exhibited an unusual Chiari network. The network observed was a combination of thread like strands and mesh with fenestrations. It was attached to the right margin of the opening of the coronary sinus. The shape of the coronary sinus opening was oval, with a transverse diameter of 15.2 mm and a maximum width of 6.5 mm. No other anomaly of the right atrium was found. The Chiari network is commonly related with patent foramen ovale and with thromboembolic phenomenon. Though found incidentally, its importance cannot be overlooked as the network is possibly associated with complications during certain intracardiac interventional procedures. The authors have presented this case with a view to add to both, the morphological and pictorial data of the said developmental variation. KEYWORDS: Chiari network, coronary sinus opening, fenestrated, mesh.

Interesting case report on Chiari network

The Chiari network is a congenital remnant that is typically found in the right atrium and is generally not associated with significant pathophysiological implications. Usually, this is detected on general routine health checkup screening or casual examination. But, occasionally in certain cases, it is possible for this condition to results in diagnostic ambiguity when assessing right atrial disorders. Additionally, it has potential to contribute to the development of thromboembolism by inducing flow blockage. The Chiari network can be accurately diagnosed by echocardiography. This network appear as a highly mobile, highly reflectant echo target at many regions in the right atrium during transthoracic and transesophageal echocardiography. In this study, we provide a case involving an 18 year old male students studying cardiac technology who was diagnosed incidentally during echocardiography practical classes with Chiari network, mild TR and mild PR. The value and precision of echocardiography are becoming more widely recognized and being used more frequently. The potential for finding normal anatomical variations and their potential incorrect interpretation as pathological states coincides with the wider implementation of this imaging method.

Chiari network with interatrial septum defect and aneurysm

Chiari network with interatrial septum defect and aneurysm

Acute ischemic stroke in a Caucasian male with long Chiari network, interatrial septal aneurysm and patent foramen ovale: A case report

Acute ischemic stroke in a Caucasian male with long Chiari network, interatrial septal aneurysm and patent foramen ovale: A case report

Abstract 18572: Mimickers of Chiari Network in the Left Atrium

Case: 84-year-old female with ischemic cardiomyopathy and severe secondary mitral regurgitation with restricted leaflet mobility due to chordae tethering and a large central regurgitant jet. She underwent trans-catheter edge to edge repair with Mitra Clip NTW. The clip was aligned in the 12 to 6 o'clock position in the middle of A2/P2 scallop and appropriate graft was obtained with good tissue bridging. The trans mitral gradient at the end of the procedure was 3 mmHg and final V-waves at 10 mmHg. After the guiding catheter was moved back to the right atrium, the transesophageal echocardiogram (TEE) showed the presence of an echo dense flickering, bubble-like mobile structure around the right upper pulmonary vein. The heart team agreed that it looked like an endothelial disruption induced by the guiding catheter. After careful consideration and using shared decision making, the patient was maintained on Eliquis for 6 months without evidence of thromboembolic phenomena. Repeat TEE showed a healed dissection flap and no echo dense structure seen previously. Discussion: Unlikely to be thrombus or air bubbles, this structure looked like what we would see in a Chiari network. Complications after Mitra Clip procedure have been well described and can be broadly divided into procedure related and device related. Endothelial disruption with the imaging characteristics shown in this case has not been described. There are no evidence-based guidelines on how to proceed with this type of complication. It is well known that endothelial damage increases the risk for thrombosis and embolic phenomena. Due to concerns of a stroke, the decision was made to start anticoagulation with the plan of redo TEE. This case demonstrates the importance of performing TEE after Mitra Clip procedure to look for lesions that would increase the risk of stroke. It also demonstrates that patients with endothelial disruption after Mitra clip may benefit from short term anticoagulation for stroke prevention.

Acute ischemic stroke in a caucasian male with long chiari network, interatrial septal aneurysm and patent foramen ovale: A case report

A 49-year-old Caucasian male, left-handed, with no known comorbidities, working as a middle school teacher, presented to the emergency room with a sudden-onset left hand weakness described as difficulty gripping with no other associated symptoms. A non-smoker, non-alcoholic beverage drinker, with no illicit drug use. There was no significant history of any neurological disease in the family background but his father has a history of interatrial septal aneurysm. Physical, cardiologic and neurologic examination at the emergency department were unremarkable aside from the weakness on his left hand and a mild sensory deficit on the left upper extremity. A cranial magnetic resonance imaging with magnetic resonance angiography was done which showed a hyperacute infarct in the right frontal lobe, with paucity of vessels and attenuation of flow-related signals in the M4 perforators of the right middle cerebral artery and contour irregularities along the intradural segment of the right vertebral artery relating to atherosclerotic changes (Figure 1). Patient was given a recombinant tissue plasminogen activator since he came in at the 3rd hour post-ictus. Laboratory tests done at the emergency department showed normal complete blood count, routine blood chemistry, A further work-up was done which showed a slightly elevated LDL on Lipid profile, and other parameters within normal limit.

EP24.29: Prenatal diagnosis of prolapsing Chiari's network

EP24.29: Prenatal diagnosis of prolapsing Chiari's network

Duo-decapolar catheter entrapment in the Chiari network: successful extraction with the snare catheter

BackgroundThe Chiari network (CN) is the net-like embryonic remnants of the right valve of the sinus venosus. Catheter entrapment by CN is a not uncommon complication during catheter manipulation inside the right atrium (RA).Case presentationA 49-year-old man with atrial fibrillation was admitted for cryoablation. Transesophageal echocardiography revealed a prominent CN in the RA. Through the sheath placed in the right femoral vein, a diagnostic electrophysiologic duo-decapolar (DD) catheter (Livewire, St Jude Medical, St Paul, MN) was advanced. The catheter tip was knotted after multiple rotations in the RA to properly locate the DD catheter at the RA wall and coronary sinus (CS). Initial attempts to disentangle the folded catheter tip by traction and rotation maneuvers were unsuccessful. We inserted the large-bore sheath (Sentrant; Medtronic, 20 Fr) into the patient’s left femoral vein and then, captured the folded catheter tip with the 20-mm circular snare catheter (Snare Kit, Medtronic, Minneapolis, MN). Then, we cut the proximal portion of the DD catheter externally and removed it retrogradely through the Flexcath sheath. We found that the catheter tip was entrapped by the fibrous tissue of the CN. After a successful retrieval, cryoablation was conducted as planned. Follow-up echocardiography did not reveal any peri-procedural complications.ConclusionsThe electrophysiological procedure that exists at the RA entails a potential risk of catheter entrapment manipulating the catheter at the RA. If catheter entrapment occurs during the procedure, the entrapped catheter may be removed via a large-bore sheath using a snare catheter.

Prominent Eustachian Valve Complicated by Thrombus

The Eustachian valve is an embryological remnant of the valve of the inferior vena cava. It may be prominent in some individuals, but the echocardiographic appearance of a divided right atrium (RA) as a result of a large Eustachian valve is rare. Sometimes it presents a problem of differential diagnosis with other embryonic remnants of the right atrium, such as the Chiari network. It may be complicated by thrombosis or infective endocarditis. Cardiac imaging plays an important role in diagnosis. The aim of this review is to discuss a rare form of Eustachian valve complicated by thrombosis.

Chiari Network: An Incidental Echocardiographic Finding in an Asymptomatic Pregnant Female

Chiari Network: An Incidental Echocardiographic Finding in an Asymptomatic Pregnant Female

Patent foramen ovale closure with the Occlutech Figulla flex II device: A long-term (up to 10-years) follow-up

BackgroundPercutaneous closure represents the first line of treatment in patients with cryptogenic stroke and documented patent foramen ovale (PFO). Scarce data report the long-term outcomes of patients undergoing PFO closure with the Figulla Flex II device (Occlutech, Germany). MethodsConsecutive patients undergoing PFO closure with a Figulla Flex II device at a single, high-volume Institution were included. Baseline clinical and procedural features were collected and patients were followed up for up to 10 years. The device's long-term safety was assessed, as well as mortality, recurrent cerebrovascular events, new-onset atrial fibrillation (AF) and residual shunt. ResultsOverall, 442 patients were included. The main indication for PFO closure was cryptogenic stroke/transitory ischemic attack (65.5%), followed by migraine (21.7%), silent lesions at MRI (10.8%), and decompression disease (2.0%). Atrial septal aneurysm was present in 20.8% of cases, Eustachian valve in 9.0%, Chiari network in 19.9%. The most frequently implanted device was the 23/25 mm (49.5% of cases). One procedural failure due to device embolization; in-hospital complications occurred in 15 cases (3.4%; 4 minor access site complications, 11 transient supraventricular tachycardias (SVT)/AF). After a follow-up of 9.2 years, 2 patients suffered recurrent TIA (with no residual R-L shunt detected). A moderate or severe residual shunt was observed in 3 patients after discharge. ConclusionsFigulla Flex II devices for PFO closure are associated with high procedural success and low incidence of adverse events even at long-term follow-up.

P177 COR TRIATRIATUM DEXTER: THE ROLE OF TRANSTHORACIC ECHOCARDIOGRAPHY

Abstract Introduction Cor triatriatum dexter (CTD) is an extremely rare congenital cardiac abnormality and its prompt recognition by transthoracic echocardiography (TTE) is essential for a correct diagnosis. Case presentation An 82–years–old woman was admitted to our cardiologic ward for worsening dyspnoea. The physical examination revealed a bilateral lower extremity oedema with elevated jugular venous pressure and hepatomegaly. The ECG showed atrial fibrillation with a heart rate of 70 bpm already treated with beta–blockers and direct–acting oral anticoagulant. TTE revealed a left ventricle with normal dimensions and function, a dilated right ventricle with a mild systolic dysfunction and increased wall thickness, a marked dilation of the right atrium and a tricuspid severe regurgitation. A deeper analysis of the right atrium revealed the presence of membrane partitioning the chamber into two compartments (Figure 1). The separation was incomplete as demonstrated by the flow across the membrane with Color–Doppler technique (Figure 2). The patient was treated using high doses of diuretics with a subsequent clinical improvement. A percutaneous intervention on the tricuspid valve was planned by the Heart Time. Discussion CTD derives from the persistence of the right valve of the sinus venosus resulting in a complete or incomplete fibromuscular band which separates the right atrium into two cavities. The spectrum of clinical manifestations is broad, based upon the degree of separation. In older patients CTD is often asymptomatic and incidentally found during diagnostic imaging examinations. TTE plays a key role in the identification of CTD, as a first–line diagnostic imaging tool. It, also, allows a differential diagnosis with a prominent eustachian valve, chiari network, and thebesian valve. However, in difficult cases a multiparametric approach is required including transoesophageal echocardiogram or cardiac magnetic resonance. Echocardiography has a pivotal role in the prompt recognition of other cardiac abnormalities associated with CTD such as atrial septal defect or patent foramen ovale, right ventricular hypoplasia and Ebstein’s anomaly. In our case, none of these were documented. Atrial fibrillation should be investigated due to severe atrial chamber dilation. A multiplane evaluation of the right atrium and the Color–Doppler technique are helpful to visualize the configuration of the membrane and evaluate the absence of flow disturbances.

Utility of intracardiac echocardiography during ablation of atrial premature depolarizations with a prominent Chiari network

Utility of intracardiac echocardiography during ablation of atrial premature depolarizations with a prominent Chiari network