The Anatomy of the Eustachian Valve-Navigating the Implications for Right-Sided Surgical and Transcatheter Cardiac Interventions

Remnants of right venous valve in utero and early postnatal life. Case report and literature review

During fetal life the right valve of the sinus venosus directs oxygenated blood from the inferior vena cava to the left atrium through the foramen ovale, until the regression of the right valve which usually occurs within the 15th week of pregnancy. Incomplete regression of the right venous valve in varying degrees can lead to different types of remnants such as the Eustachian valve, the Chiari Network and Cor Triatriatum Dexter. Prenatal diagnosis of remnants of right venous valve has only rarely been reported in the literature. We present a case of prenatal diagnosis of Chiari Network associated with severe tricuspid regurgitation, further complicated by tachyarrhythmia and signs of fetal heart failure with the appearance of abundant pleural and ascitic effusion. A cesarean section was performed at 32 weeks. After 48 h of life, because of persistence of atrial flutter, an electrical cardioversion was performed. The physical examination 7 months after being discharged showed a normal growth, good condition and persistence of mild tricuspid regurgitation. We also reviewed the available evidence on persistent right venous valve diagnosed in utero or early postnatal life. In conclusion we believe that prenatal recognition is helpful in planning fetal surveillance identifying those newborns at risk of dyspnea, cyanosis or neonatal heart failure.

Chiari network for the interventional cardiologist: A hidden enemy at the heart gate - A systematic review of the literature

BACKGROUND

This study aimed to collect and analyze the literature data regarding Chiari network (CN) and other right atrium (RA) remnants comprising the Eustachian and Thebesian valves (EV, ThV) as a potential entrapment site during different percutaneous cardiac procedures (PCP).

METHODS AND RESULTS

A systematic search was conducted using Pubmed and Embase databases following the PRISMA guidelines to obtain available data concerning PCP associated with entrapment of inserted materials within CN-EV-ThV. The final analysis included 41 patients who underwent PCP with reported material entrapment within these RA remnants. The PCP was atrial septal defect (ASD)/patent foramen ovale (PFO) closure, catheter ablation, and pacemaker/defibrillator implantation in 44%, 22%, and 17% of patients, respectively. The entrapped materials were ASD/PFO devices, multipolar electrophysiology catheters, passive-fixation pacing leads, and J-guidewires in about 30%, 20%, 15%, and 10% of patients, respectively. Intraprocedural transthoracic, transoesophageal and intracardiac echocardiography showed sensitivity to reveal these structures of 20%, ∼95%, and 100%, respectively. A percutaneous approach successfully managed 70% of patients, while cardiovascular surgery was required in 20% and three patients died (7.3%).

CONCLUSIONS

CN and other RA remnants may cause entrapment of various devices or catheters during PCP requiring right heart access. The percutaneous approach, guided by intraprocedural imaging, appears safe and effective in managing most patients. Prevention includes recognizing these anatomical structures at baseline cardiac imaging and intraprocedural precautions. Further studies are needed to analyze the actual incidence of this condition, its clinical impact and appropriate management.

Transesophageal Echocardiography Guided Partial Right Atrial Inflow Occlusion - A Case Study

Deployment of stent-grafts and other endovascular devices is a common technique for various vascular repair procedures. Induced, transient, periods of hypotension are essential to the precise deployment of a device as this minimizes displacement that can result from high pressure aortic flow. Partial inflow occlusion of the right atrium is a reliable, precise, and safe method of achieving this. We present a case where intraoperative transesophageal echocardiography (TEE) was used to guide and confirm balloon placement for right atrium inflow occlusion during a thoracic endovascular aneurysm repair (TEVAR) procedure for repair of an aortic dissection in a 67 year old male. This highlights a novel use of TEE in the context of endovascular surgery, and showcases an alternative method of reliably achieving transient hypotension.

Case of eustachian valve endocarditis and the importance of synergistic antibiotic therapy

A 46-year-old woman with a history of end-stage renal disease on chronic haemodialysis presented with 1 week of fever, chills, altered mental status and hand pain. She was febrile and ill-appearing on presentation with a pulse rate of 102 beats per minute. She had a tunnelled dialysis catheter in her right neck. Hand examination demonstrated a swollen, erythematous and tender wrist. Cardiovascular examination demonstrated no murmurs. CT of the hand showed abscesses involving the left forearm. Blood and abscess cultures grew methicillin-resistant Staphylococcus aureus (MRSA). Transesophageal echocardiography (TEE) showed a 1.0×1.0 cm mobile vegetation involving the eustachian valve (EV), confirming EV endocarditis. She remained bacteraemic for 18 days despite being on vancomycin with appropriate blood levels. Vancomycin was switched to daptomycin and ceftaroline, which cleared her cultures. Repeat TEE showed improved vegetation size. Our case highlights the rarity and management of EV endocarditis and the importance of synergy for treatment of persistent MRSA bacteraemia.