Empirical superior vena cava electrical isolation guided by quantitative ablation index improves outcomes of radiofrequency catheter ablation for paroxysmal atrial fibrillation.

BACKGROUND: The value of empirical superior vena cava isolation (SVCI) following pulmonary vein isolation (PVI) to improve the efficacy of radiofrequency catheter ablation (RFCA) for paroxysmal atrial fibrillation (PAF) remains controversial. OBJECTIVE: To evaluate the efficacy and safety of quantitative ablation index (AI)-guided empirical SVCI, in addition to PVI, for patients with PAF. METHODS: Patients with symptomatic PAF who underwent RFCA between October 2021 and May 2023 were retrospectively analysed. Patients were categorised into PVI-only group and PVI+SVCI group based on the intraoperative ablation strategy. RFCA was guided by quantitative AI in both groups. Regular clinical follow-ups were conducted to detect AF recurrence, defined as any episode of atrial fibrillation, atrial flutter or atrial tachycardia lasting >30 s. RESULTS: A total of 246 patients were enrolled, with 108 patients in the PVI group and 138 patients in the PVI+SVCI group. Compared with the PVI group, patients in the PVI+SVCI group had a higher prevalence of coronary artery disease (p=0.04), stroke (p=0.02) and a smaller left atrial diameter (p<0.01). After a follow-up period of 16±6 months, the ablation success rate was significantly higher in the SVCI+PVI group compared with the PVI group (91.3% vs 81.5%, p=0.02). Multivariable logistic regression analysis indicated that SVCI was an independent predictor of reduced AF recurrence postablation (Relative Risk [RR] 0.4, 95% CI 0.19 to 0.90, p=0.026). No significant difference in complication rates was observed between the groups. CONCLUSION: Quantitative AI-guided empirical SVCI, in addition to PVI, improves the success rate of RFCA for PAF without increasing the risk of complications.

Utility of covered stents as a bypass for the treatment of central venous occlusion: a case report.

BACKGROUND: Central venous occlusion (CVO) is difficult to treat with percutaneous transluminal angioplasty because the guidewire cannot pass through the occluded segments. In this study, we devised a new method for establishing an extra-anatomic bypass between the right subclavian vein and the superior vena cava via a covered stent to treat whole-segment occlusion of the right brachiocephalic vein (BCV) with calcification. CASE PRESENTATION: We present the case of a 58-year-old female patient who complained of right arm swelling present for 1.5 years. Twelve years prior, the patient began hemodialysis because chronic glomerulonephritis had progressed to end-stage renal disease. During the first 3 years, a right internal jugular vein (IJV)-tunneled cuffed catheter was used as the dialysis access, and the catheter was replaced once. A left arteriovenous fistula (AVF) was subsequently established. Owing to occlusion of the left AVF, a new fistula was established on the right upper extremity 1.5 years prior to this visit. Angiography of the right upper extremity revealed complete occlusion of the right BCV and IJV with calcification. Because of the failure to pass the guidewire across the lesion, we established an extra-anatomic bypass between the right subclavian vein and the superior vena cava with a covered stent. Angiography confirmed the patency of whole vascular access system. After 3 months of follow-up, the patient's AVF function and the bypass patency were satisfactory. CONCLUSIONS: As a new alternative for the treatment of long, angled CVO with or without calcification, a covered stent can be used to establish an extravascular bypass between central veins.

RF catheter ablation of AVNRT in a patient with interrupted inferior vena cava anomaly with hemiazygos continuity with persistent left superior vena cava.

Intrahepatic interruption of the inferior vena cava (IVC) with continued hemizygous is a very rare abnormality and sometimes it may be accompanied by other cardiovascular abnormalities. Continuation of the hemizygous vein draining into the right atrium through the left superior vena cava (LSVC) is much rarer. In this paper, we have presented a patient who had simultaneous IVC interrupted with persistent LSVC and suffered from Atrioventricular nodal reentrant tachycardia (AVNRT). Finally, radiofrequencies (RF) catheter ablation for AVNRT was successfully performed through a left subclavian vein access.

Ischemic Heart Disease with In-Stent Re-Stenosis with Complete Heart Block and Isolated Persistent Left Superior Vena Cava - Rare Case Report with Challenges and Clinical Implications.

ABSTRACT: Isolated persistent left superior vena cava (PLSVC) is a very rare congenital thoracic venous system anomaly and is commonly an incidental finding, usually detected during central venous access, cardiac catheterization, or cardiothoracic surgeries. This is a rare case report wherein the patient is a known case of ischemic heart disease with s/p percutaneous transluminal coronary angioplasty (PTCA) with a stent to left anterior descending (LAD) artery with in-stent re-stenosis presented with complete heart block and had an unanticipated discovery of isolated PLSVC on facing difficulty during the transvenous approach of permanent pacemaker implantation (PPI). In this case report, we inspect the challenges associated with and various clinical implications of isolated PLSVC.

CT anatomical study of extreme lateral interbody fusion in thoracic spine.

Extreme Lateral Interbody Fusion (XLIF) is currently used in the clinical treatment of thoracic spine disorders and has achieved desirable results. In this study, we selected CT images of the thoracic spine from 54 patients and divided the intervertebral spaces into six regions (A, I, II, III, IV, P) using the Moro method. We observed the adjacent relationships between the thoracic spine and surrounding tissues such as the scapula, esophagus, thoracic aorta, and superior vena cava. We made four main findings: firstly, when the scapulae were symmetrical on both sides, over 80% of patients had the T1-4 II-III region obstructed by the scapulae; secondly, when the esophagus was located on the left side of the vertebral body, 3.7% to 24.1% of patients had the T4-9 region located in the II-III zone; furthermore, when the thoracic aorta was on the left side of the vertebral body, over 80% of individuals in the T4-9 segment occupied the II-III region, with the values being 55.5% and 20.4% for T9/10 and T10/11, respectively; finally, the superior vena cava was located on the right side of the T4/5 vertebra, with 3.7% of individuals having it in the II-III region, while on the left side of T5-9, 3.7% to 18.5% of individuals had it in the II-III region. Based on these findings, we suggest that XLIF should not be performed on the T1-4 vertebrae due to scapular obstruction. Selecting the left-sided approach for XLIF in the T4-11 segments may risk injuring the thoracic aorta, esophagus, and superior vena cava, while the T11/12 segment is considered safe and feasible. Choosing the right-sided approach for XLIF may pose a risk of injuring the superior vena cava in the T4/5 segment, but it is safe and feasible in the T5-12 segments.

Head-to-Head Comparison of Hepatic Vein and Superior Vena Cava Flow Velocity Waveform Analyses for Predicting Elevated Right Atrial Pressure.

OBJECTIVE: Blood flow in the hepatic veins and superior vena cava (SVC) reflects right heart filling; however, their Doppler profiles are often not identical, and no studies have compared their diagnostic efficacies. We aimed to determine which venous Doppler profile is reliable for detecting elevated right atrial pressure (RAP). METHODS: In 193 patients with cardiovascular diseases who underwent cardiac catheterization within 2 d of echocardiography, the hepatic vein systolic filling fraction (HV-SFF) and the ratio of the peak systolic to diastolic forward velocities of the SVC (SVC-S/D) were measured. HV-SFF < 55% and SVC-S/D < 1.9 were regarded as elevated RAP. We also calculated the fibrosis 4 index (FIB-4) as a serum liver fibrosis marker. RESULTS: HV-SFF and SVC-S/D were feasible in 177 (92%) and 173 (90%) patients, respectively. In the 161 patients in whom both venous Doppler waveforms could be measured, HV-SFF and SVC-S/D were inversely correlated with RAP (r = -0.350, p < 0.001; r = -0.430, p < 0.001, respectively). SVC-S/D > 1.9 showed a significantly higher diagnostic accuracy of RAP elevation compared with HV-SFF < 55% (area under the curve, 0.842 vs. 0.614, p < 0.001). Multivariate analyses showed that both FIB-4 (ß = -0.211, p = 0.013) and mean RAP (ß = -0.319, p < 0.001) were independent determinants of HV-SFF. In contrast, not FIB-4 but mean RAP (ß = -0.471, p < 0.001) was an independent determinant of SVC-S/D. The diagnostic accuracy remained unchanged when HV-SFF < 55% was considered in conjunction with the estimated RAP based on the inferior vena cava morphology. Conversely, SVC-S/D showed an incremental diagnostic value over the estimated RAP. CONCLUSIONS: SVC-S/D enabled a more accurate diagnosis of RAP elevation than HV-SFF.

Superior vena cava isolation using a pentaspline pulsed-field ablation catheter: feasibility and safety in patients undergoing atrial fibrillation catheter ablation.

AIMS: Superior vena cava (SVC) isolation during atrial fibrillation catheter ablation is limited by the risk of collateral damage to the sinus node and/or the phrenic nerve. Due to its tissue-specificity, we hypothesized the feasibility and safety of pulsed-field ablation (PFA)-based SVC isolation. METHODS AND RESULTS: One hundred and five consecutive patients undergoing PFA-based AF catheter ablation were prospectively included. After pulmonary vein isolation (±posterior wall isolation and electrical cardioversion), SVC isolation was performed using a standardized workflow. Acute SVC isolation was achieved in 105/105 (100%) patients after 6 ± 1 applications. Transient phrenic nerve stunning occurred in 67/105 (64%) patients but without phrenic nerve palsy at the end of the procedure and at hospital discharge. Transient high-degree sinus node dysfunction occurred in 5/105 (4.7%) patients, with no recurrence at the end of the procedure and until discharge. At the 3-month follow-up visit, no complication occurred. CONCLUSION: SVC isolation using a pentaspline PFA catheter is feasible and safe.

Transcatheter Correction of Superior Venacaval Form of Sinus Venosus Defects Using Balloon-Mounted Covered STENTS.

Superior sinus venosus defects (SVD) are interatrial communications located above the confines of the oval fossa, where unroofing of the right upper pulmonary vein leads to its anomalous drainage to the superior venacava. Recent emergence of transcatheter closure of these defects using covered stents is an attractive alternative option especially in adults with additional comorbidities. This article focuses on various aspects of non-surgical closure of SVD, including patient selection, appropriate hardware options, step-by-step procedural details, evolution and modifications in the techniques over the last decade, protocols for follow-up evaluation, and potential complications associated with this intervention.

A Double Rarity: Lost intravascular Catheter Guidewire in Persistent Left Superior Vena Cava and Coronary Sinus - A Case Report.

Guidewire loss is a rare complication of central venous catheterization. A 65-year-old male was hospitalized in a high-dependency unit for exacerbation of chronic obstructive pulmonary disease, pneumonia, erythrocytosis, and clinical signs of heart failure. Upon admission, after an unsuccessful right jugular approach, a left jugular central venous catheter was placed. The next day, chest radiography revealed the catheter located in the left parasternal region, with suspected retention of the guidewire, visually confirmed by the presence of its proximal end inside the catheter. The left parasternal location of the catheter and the typical projection of the guidewire in the coronary sinus, later confirmed by echocardiography, raised suspicion of a persistent left superior vena cava (PLSVC). Agitated saline injected into the left antecubital vein confirmed bubble entry from the coronary sinus into the right atrium. After clamping the guidewire, the catheter was carefully retrieved along with the guidewire without any complications. This is the first reported case of guidewire retention in PLSVC and coronary sinus. It underscores the potential causes of guidewire loss and advocates preventive measures to avoid this potentially fatal complication.

Intracranial Pressure and Cerebral Hemodynamics in Infants Before and After Glenn Procedure.

OBJECTIVES: This prospective cohort study aimed to investigate changes in intracranial pressure (ICP) and cerebral hemodynamics in infants with congenital heart disease undergoing the Glenn procedure, focusing on the relationship between superior vena cava pressure and estimated ICP. DESIGN: A single-center prospective cohort study. SETTING: The study was conducted in a cardiac center over 4 years (2019-2022). PATIENTS: Twenty-seven infants with congenital heart disease scheduled for the Glenn procedure were included in the study, and detailed patient demographics and primary diagnoses were recorded. INTERVENTIONS: Transcranial Doppler (TCD) ultrasound examinations were performed at three time points: baseline (preoperatively), postoperative while ventilated (within 24-48 hr), and at discharge. TCD parameters, blood pressure, and pulmonary artery pressure were measured. MEASUREMENTS AND MAIN RESULTS: TCD parameters included systolic flow velocity, diastolic flow velocity (dFV), mean flow velocity (mFV), pulsatility index (PI), and resistance index. Estimated ICP and cerebral perfusion pressure (CPP) were calculated using established formulas. There was a significant postoperative increase in estimated ICP from 11 mm Hg (interquartile range [IQR], 10-16 mm Hg) to 15 mm Hg (IQR, 12-21 mm Hg) postoperatively (p = 0.002) with a trend toward higher CPP from 22 mm Hg (IQR, 14-30 mm Hg) to 28 mm Hg (IQR, 22-38 mm Hg) postoperatively (p = 0.1). TCD indices reflected alterations in cerebral hemodynamics, including decreased dFV and mFV and increased PI. Intracranial hemodynamics while on positive airway pressure and after extubation were similar. CONCLUSIONS: Glenn procedure substantially increases estimated ICP while showing a trend toward higher CPP. These findings underscore the intricate interaction between venous pressure and cerebral hemodynamics in infants undergoing the Glenn procedure. They also highlight the remarkable complexity of cerebrovascular autoregulation in maintaining stable brain perfusion under these circumstances.

Biomechanical Analysis of Age-Dependent Changes in Fontan Power Loss.

The hemodynamics in Fontan patients with single ventricles rely on favorable flow and energetics, especially in the absence of a subpulmonary ventricle. Age-related changes in energetics for extracardiac and lateral tunnel Fontan procedures are not well understood. Vorticity (VOR) and viscous dissipation rate (VDR) are two descriptors that can provide insights into flow dynamics and dissipative areas in Fontan pathways, potentially contributing to power loss. This study examined power loss and its correlation with spatio-temporal flow descriptors (vorticity and VDR). Data from 414 Fontan patients were used to establish a relationship between the superior vena cava (SVC) to inferior vena cava (IVC) flow ratio and age. Computational flow modeling was conducted for both extracardiac conduits (ECC, n = 16) and lateral tunnels (LT, n = 25) at different caval inflow ratios of 2, 1, and 0.5 that corresponded with ages 3, 8, and 15+. In both cohorts, vorticity and VDR correlated well with PL, but ECC cohort exhibited a slightly stronger correlation for PL-VOR (>0.83) and PL-VDR (>0.89) than that for LT cohort (>0.76 and > 0.77, respectively) at all ages. Our data also suggested that absolute and indexed PL increase (p < 0.02) non-linearly as caval inflow changes with age and are highly patient-specific. Comparison of indexed power loss between our ECC and LT cohort showed that while ECC had a slightly higher median PL for all 3 caval inflow ratio examined (3.3, 8.3, 15.3) as opposed to (2.7, 7.6, 14.8), these differences were statistically non-significant. Lastly, there was a consistent rise in pressure gradient across the TCPC with age-related increase in IVC flows for both ECC and LT Fontan patient cohort. Our study provided hemodynamic insights into Fontan energetics and how they are impacted by age-dependent change in caval inflow. This workflow may help assess the long-term sustainability of the Fontan circulation and inform the design of more efficient Fontan conduits.

NASCI case of the month: "Unroofed coronary sinus without persistent left-sided superior vena cava".

Unroofed sinus is categorized into four subtypes. Types I and II represent complete unroofing with or without an LSVC, respectively [1]. Types III and IV are partial unroofing involving the mid-CS (type III) or near the LA appendage and left superior pulmonary vein (type IV) [1]. CT has advantages over echocardiography in detection of this anomaly (illustrated in this case) as well as in precise delineation of defect and associated findings (presence or absence of LSVC). Short axis reconstructions at the level of CS are helpful in diagnosis. Considerations for repair include location of CS defect, presence of LSVC and other abnormalities as well as comorbidity risks [2].

Incidentally diagnosed superior vena cava narrowing prompted by screening mammography.

An adult woman with a prior history of treated non-Hodgkin's lymphoma presented for screening mammography, which incidentally demonstrated dilated veins throughout the bilateral breasts. Concern for a superior vena cava stenosis or obstruction was raised despite the patient being asymptomatic; the patient underwent further imaging with chest CT, which revealed focal stenosis of the superior vena cava, attributed to fibrosis secondary to prior radiation therapy. Superior vena cava syndrome (SVCS), the spectrum of disease caused by superior vena cava narrowing or obstruction, requires prompt investigation given its association with intrathoracic malignancy, primary lung cancer and poor outcomes. This report explores the benign and malignant causes, signs and symptoms, preferred investigations, and treatment of SVCS. This case highlights the potential importance of screening mammography in revealing unexpected ancillary diagnoses, especially in high-risk patients.

Case Series and Review of Literature for Superior Vena Cava Injury During Laser Lead Extraction.

Transvenous laser lead extraction poses a risk of major complications (0.19%-1.8%), notably injury to the superior vena cava (SVC) in 0.19% to 0.96% of cases. Various factors contribute to SVC injury, which can be categorized as patient-related (such as female gender, low body mass index, diabetes, renal problems, anemia, and reduced ejection fraction), device-related (including the number, dwell time, and type of leads), or procedural-related (such as reason for extraction, venous obstructions, and bilateral lead placements).

Challenge Accepted: Lead Extraction in a Patient with Persistent Left Superior Vena Cava and Right Superior Vena Cava Occlusion.

Persistent left superior vena cava (PLSVC) is an anatomic variant that is relatively uncommon in the general population. Lead extraction through PLSVC is extremely rare. Due to unusual anatomy, the procedure carries challenges that require special considerations and careful planning. The authors report a case of lead extraction through a PLSVC with occluded right superior vena cava and highlight the challenges and outcomes of the procedure.

Successful catheter ablation of atrial tachycardia initiated with orthodromic capture of superior vena cava potentials.

A case of successful catheter ablation of paroxysmal atrial fibrillation and atrial tachycardia is reported. After pulmonary vein isolation, atrial tachycardia was induced by the use of isoproterenol and burst pacing from the catheter in the right atrium. An attempt was made to create a three-dimensional (3D) map of the atrial tachycardia, but the atrial tachycardia was terminated in the middle of the mapping. The 3D map was insufficient but indicated that the superior vena cava was involved in the circuit. When the intracardiac electrograms were reviewed, it was found that the atrial tachycardia was initiated with orthodromic capture of superior vena cava potentials and it was considered that the atrial tachycardia involved the superior vena cava-right atrium junction. Accordingly, superior vena cava isolation was performed. After that, atrial fibrillation and atrial tachycardias were not induced by the use of isoproterenol and burst pacing. In this case, an intracardiac electrogram at the time of induction of the tachycardia was helpful for understanding the circuit of the tachycardia.