Impact of 4D-Flow CMR Parameters on Functional Evaluation of Fontan Circulation

We sought to evaluate the potential clinical role of 4D-flow cardiac magnetic resonance (CMR)-derived energetics and flow parameters in a cohort of patients' post-Fontan palliation. In patients with Fontan circulation who underwent 4D-Flow CMR, streamlines distribution was evaluated, as well a 4D-flow CMR-derived energetics parameters as kinetic energy (KE) and energy loss (EL) normalized by volume. EL/KE index as a marker of flow efficiency was also calculated. Cardiopulmonary exercise test (CPET) was also performed in a subgroup of patients. The population study included 55 patients (mean age 22 ± 11 years). The analysis of the streamlines revealed a preferential distribution of the right superior vena cava flow for the right pulmonary artery (62.5 ± 35.4%) and a mild preferential flow for the left pulmonary artery (52.3 ± 40.6%) of the inferior vena cave-pulmonary arteries (IVC-PA) conduit. Patients with heart failure (HF) presented lower IVC/PA-conduit flow (0.75 ± 0.5 vs 1.3 ± 0.5 l/min/m2, p = 0.004) and a higher mean flow-jet angle of the IVC-PA conduit (39.2 ± 22.8 vs 15.2 ± 8.9, p < 0.001) than the remaining patients. EL/KE index correlates inversely with VO2/kg/min: R: - 0.45, p = 0.01 peak, minute ventilation (VE) R: - 0.466, p < 0.01, maximal voluntary ventilation: R:0.44, p = 0.001 and positively with the physiological dead space to the tidal volume ratio (VD/VT) peak: R: 0.58, p < 0.01. From our data, lower blood flow in IVC/PA conduit and eccentric flow was associated with HF whereas higher EL/KE index was associated with reduced functional capacity and impaired lung function. Larger studies are needed to confirm our results and to further improve the prognostic role of the 4D-Flow CMR in this challenging population.

It's a long way to the top! Congenital venous anomalies and left isomerism limiting atrial fibrillation transcatheter ablation

BACKGROUND

Atrial fibrillation is the most common sustained cardiac arrhythmia in adults and it is associated with a high burden of mortality and morbidity worldwide. Catheter ablation is increasingly used to improve symptoms and prognosis in selected patients. Lower limb venous access with subsequent transseptal approach to the left atrium is the standard procedure for atrial fibrillation catheter ablation.

CASE PRESENTATION

We report an unusual case of complex venous anomaly with a left-sided inferior vena cava with hemiazygos continuation to a persistent left superior vena cava draining in an enlarged coronary sinus in a patient with persistent atrial fibrillation scheduled for transcatheter ablation.

DISCUSSION

Lower limb venous anomalies may limit a standard transseptal approach to the left atrium thus precluding an effective catheter ablation procedure for atrial fibrillation. Alternative interventions, such as unconventional percutaneous access, thoracoscopic approach and "ablate and pace" procedures, may be necessary in patients with symptomatic atrial fibrillation and complex venous anomalies.

Catheter ablation of the left-sided variant of right top pulmonary vein in a case with persistent left superior vena cava

A 50-year-old woman underwent catheter ablation for atrial fibrillation. Preoperative computed tomography revealed a left-sided variant of the right top pulmonary vein (PV) and a persistent left superior vena cava. The right top PV was successfully isolated through a wide antral circumferential ablation line simultaneously with the right PVs.

Prenatal Diagnosis and Postnatal Outcomes of Persistent Left Superior Vena Cava Associated With Mild Narrow Aorta: A Cohort Study

PURPOSE

To explore prenatal ultrasonic features and prognosis of the persistent left superior vena cava (PLSVC) complicated with mild narrow aorta.

MATERIALS AND METHODS

A retrospective study was conducted involving 1348 fetuses diagnosed with PLSVC prenatally between January 2016 and December 2019. Forty-five fetuses with PLSVC associated with mild narrow aorta were selected from the cohort as the study group and 79 fetuses with isolated PLSCV were recruited randomly as the control group. All clinical and ultrasound results, including images and parameters of cardiac structures, were reviewed retrospectively. General conditions, ultrasound (US) measurements, and fetal prognosis were compared between the groups.

RESULTS

Aorta valve diameter (AOD), Z-score of aorta valve (AODz-score), aortic isthmus diameter (AOIsD), and pulmonary diameter (PAD)/AOD were significantly different in study group than control group no matter in the second or third trimester. Thirty-eight fetuses in study group were born with favorable outcomes after long-term follow-up. A total of 13.16% (5/38) remain mild narrow aorta and 3 of them showed smaller left ventricle after 3 years follow up. Prenatal AODz-score in infants remains mild narrow aorta after 2 years aged was higher than ones' aorta return to normal (P = .01), especially when AODz-score >1.725. Moreover, when prenatal ratio of AOIsD/left subclavian artery was <1.12, it was more likely that the aorta would remain mildly narrow at age 2.

CONCLUSION

Fetuses diagnosed with PLSVC with mild narrow aorta had favorable prognosis. AODz-score and AOIsD/left subclavian artery may be two predictors that reveal the risk of a mildly narrowed aorta remaining after birth.

On the way to the azygos vein: a road of return rather than ruined

BACKGROUND

The malposition of central venous catheters (CVCs) may lead to vascular damage, perforation, and even mediastinal injury. The malposition of CVC from the right subclavian vein into the azygos vein is extremely rare. Here, we report a patient with CVC malposition into the azygos vein via the right subclavian vein. We conduct a comprehensive review of the anatomical structure of the azygos vein and the manifestations associated with azygos vein malposition. Additionally, we explore the resolution of repositioning the catheter into the superior vena cava by carefully withdrawing a specific length of the catheter.

CASE PRESENTATION

A 79-year-old female presented to our department with symptoms of complete intestinal obstruction. A double-lumen CVC was inserted via the right subclavian vein to facilitate total parenteral nutrition. Due to the slow onset of sedative medications during surgery, the anesthetist erroneously believed that the CVC had penetrated the superior vena cava, leading to the premature removal of the CVC. Postoperative contrast-enhanced computed tomography of the chest confirmed that the central venous catheter had not penetrated the superior vena cava but malpositioned into the azygos vein. The patient was discharged 15 days after surgery without any complications.

CONCLUSIONS

CVC malposition into the azygos vein is extremely rare. Clinical practitioners should be vigilant regarding this form of catheter misplacement. Ensuring the accurate positioning of the CVC before each infusion is crucial. Utilizing chest X-rays in both frontal and lateral views, as well as chest computed tomography, can aid in confirming the presence of catheter misplacement.

[Real-time localization for port-implanted catheter tip by echocardiographic guidance]

The clinical data of 23 patients undergoing real-time echocardiography-guided infusion port implantation in the Breast Center of Tsinghua Changgung Hospital in Beijing from January to July 2021 were analyzed. The length of catheter insertion L1 was initially estimated using surface measurement method in all patients. Intraoperatively, transthoracic echocardiography was applied using the parasternal four-chamber view to visualize the catheter image within the right atrium, and the length of catheter insertion L2 was recorded under the guidance of echocardiography. Postoperatively, chest radiographs were taken in the upright position to observe the position of the catheter tip. According to chest CT scans, the ideal length (L) for catheter tip placement was calculated when it was located at the junction of superior vena cava and right atrium. Bland-Altman scatter plot analysis and linear regression fitting test were used on L1 and L2 respectively with L to evaluate the consistency. A total of 23 patients were included in this study, among which one case of left breast cancer patient undergoing breast-conserving surgery had difficulty in identifying the catheter tip position due to residual pleural effusion obscuring the imaging of the cardiac apex four-chamber view. In 22 patients, the results of intraoperative ultrasound imaging were good, including 1 case of catheter ectopic to azygos vein, and 21 cases of right atrial catheter could be detected by ultrasound. Statistical analysis showed that there was a good consistency between L1 and L, L2 and L, and the difference between them was d=0.28 cm (95%CI:-1.76-2.31 cm) and d=0.20 cm(95%CI:-0.84-1.23 cm), respectively, with no statistical significance (P>0.05). In the linear regression model, L2 and L had a higher fit than L1, and the difference was statistically significant (R²=0.954, P<0.001). This study found that real-time echocardiographic localization technique can be applied in adult port surgery to replace X-ray-guided real-time catheter tip detection and adjustment to the optimal position.

A rare case of isolated persistent left superior vena cava diagnosed by echocardiography

BACKGROUND

The persistent left superior vena cava (PLSVC) is an infrequent vascular variant. PLSVC with absent right superior vena cava, also known as isolated PLSVC, is an exceptionally rare entity. In this case we present a patient with isolated PLSVC draining to coronary sinus, diagnosed incidentally during echocardiography.

CASE PRESENTATION

A 35-year-old man underwent a transthoracic echocardiography which showed an enormously dilated coronary sinus. Hand-agitated saline was injected via peripheral intravenous cannulas. The contrast appeared firstly in the coronary sinus before it opacified the right atrium. Since this was also visible by the right antecubital saline injection, it indicated an extremely rare case of PLSVC with the absence of right superior vena cava which was confirmed by cardiac magnetic resonance.

CONCLUSIONS

The finding of a distinctively dilated coronary sinus in echocardiography led us to further investigation using agitated saline that revealed an infrequent anomaly termed isolated PLSVC. The in-depth diagnosis of this vascular variant is crucial considering that it may lead to important clinical implications, such as difficulties with central venous access, especially in the current era of a rapid development of cardiac device therapies.

Rare case of total anomalous pulmonary venous return into the right atrium in situs solitus

We report an uncommon case report of total anomalous pulmonary venous returns into the right atrium at the base of the superior caval vein's ostium without a sinus venosus defect, in situs solitus, without vertical vein or a posterior pulmonary venous confluence.

Association of Prenatally Diagnosed Isolated Single Left Superior Vena Cava and Postnatal Development of Coarctation of the Aorta

To report the prevalence of coarctation of the aorta (CoA) in fetuses with single left superior vena cava (SL-SVC) and to evaluate changes in echocardiographic measurements. Additionally, to report the prevalence of associated malformations. Retrospective observational study of fetuses diagnosed with SL-SVC between 2012 and 2021 at a tertiary fetal cardiology unit. In fetuses without intracardiac abnormalities, Z-scores of the ventricles, great arteries, and Doppler flow patterns are reported. We identified 47 fetuses with SL-SVC of which 8/47 (17%) had abnormal intracardiac anatomy. One fetus was lost to follow-up. Of those with normal intracardiac anatomy and postnatal follow-up (38), karyotype abnormalities were confirmed in 2/38 (5%) and ECA in 8/38 (21%). 33/38 were live-born. None developed CoA postnatally. Paired analysis of Z-scores between early and late scans of 24 fetuses showed that diameters of the right heart structures and Doppler flows of tricuspid valve increased significantly during pregnancy, while the left heart structures and flow patterns did not change. The median risk of CoA did not change between the early and the late scan. We did not observe CoA in this cohort. A degree of ventricular asymmetry was present, but this was due to right heart dominance rather than hypoplasia of left heart structures. This likely reflects redistribution of blood and does not appear to confer increased risk of CoA. Predictive models of the postnatal development of CoA which set the dimensions of right and left heart structures in relation might not be applicable in this situation.

Impact of Age-Related Change in Caval Flow Ratio on Hepatic Flow Distribution in the Fontan Circulation

BACKGROUND

The Fontan operation is a palliative technique for patients born with single ventricle heart disease. The superior vena cava (SVC), inferior vena cava (IVC), and hepatic veins are connected to the pulmonary arteries in a total cavopulmonary connection by an extracardiac conduit or a lateral tunnel connection. A balanced hepatic flow distribution (HFD) to both lungs is essential to prevent pulmonary arteriovenous malformations and cyanosis. HFD is highly dependent on the local hemodynamics. The effect of age-related changes in caval inflows on HFD was evaluated using cardiac magnetic resonance data and patient-specific computational fluid dynamics modeling.

METHODS

SVC and IVC flow from 414 patients with Fontan were collected to establish a relationship between SVC:IVC flow ratio and age. Computational fluid dynamics modeling was performed in 60 (30 extracardiac and 30 lateral tunnel) patient models to quantify the HFD that corresponded to patient ages of 3, 8, and 15 years, respectively.

RESULTS

SVC:IVC flow ratio inverted at ≈8 years of age, indicating a clear shift to lower body flow predominance. Our data showed that variation of HFD in response to age-related changes in caval inflows (SVC:IVC, 2, 1, and 0.5 corresponded to ages, 3, 8, and 15+, respectively) was not significant for extracardiac but statistically significant for lateral tunnel cohorts. For all 3 caval inflow ratios, a positive correlation existed between the IVC flow distribution to both the lungs and the HFD. However, as the SVC:IVC ratio changed from 2 to 0.5 (age, 3-15+) years, the correlation's strength decreased from 0.87 to 0.64, due to potential flow perturbation as IVC flow momentum increased.

CONCLUSIONS

Our analysis provided quantitative insights into the impact of the changing caval inflows on Fontan's long-term HFD, highlighting the importance of SVC:IVC variations over time on Fontan's long-term hemodynamics. These findings broaden our understanding of Fontan hemodynamics and patient outcomes.

Complete free wall isolation of arrhythmogenic persistent left superior vena cava

INTRODUCTION

Persistent left superior vena cava (PLSVC) is one of the major sources of triggers and drivers of atrial fibrillation (AF). There has been no established PLSVC ablation procedure to eliminate the arrhythmogenicity along the entire length of PLSVC.

METHODS AND RESULTS

A 70-year-old woman with a history of two previous catheter ablations for AF, mitral valvuloplasty, and an unroofed coronary sinus-type atrial septal defect closure underwent the redo AF ablations. The AF trigger and driver were identified within the patient's enlarged PLSVC. The AF was treated by complete PLSVC free wall isolation.

CONCLUSION

Complete PLSVC free wall isolation may be an effective ablation method to eliminate the arrhythmogenicity along the entire length of the PLSVC.

Giant coronary sinus aneurysm: an incidental discovery in a case of acute coronary syndrome

Coronary sinus (CS) anomalies, although infrequent, are increasingly diagnosed with advances in interventional procedures and imaging techniques. Most cases are asymptomatic and incidentally diagnosed. We present a case of an elderly male without comorbidities who presented with acute angina. Coronary catheterisation revealed a double-vessel disease, but incidentally, sequential angiograms captured contrast filling in the levophase of CS, revealing a giant CS. Primary percutaneous angioplasty of the right coronary artery was performed successfully. Echocardiography confirmed the aneurysm, and a CT scan showed an aneurysmally dilated CS and other coronary veins alongside a normal-sized persistent left superior vena cava draining to the right atrium through CS. CS aneurysms may lead to complications such as thrombosis, embolic events, arrhythmias and heart failure, stressing the importance of vigilant monitoring and timely intervention. This case underscores the significance of recognising CS anomalies in cardiac procedures, even when asymptomatic, for proper management.

Resection and a rare type of reconstruction of the superior vena cava with the left brachiocephalic vein

Resection and reconstruction of the superior vena cava (SVC) are required in a selected group of patients with anterior mediastinal tumors and lung neoplasms. We present the case of a 63-year-old woman who underwent invasive type B2 thymoma resection and a rare type of reconstruction of the superior vena cava using a patch of the left brachiocephalic vein (LBV). The various types of reconstruction of the superior vena cava are discussed.

Persistant Left Superior Vena Cava with and Without Right Superior Vena Cava: Significance of Prenatal Diagnosis

This study aims to define the associated anomalies with PLSVC, and to compare single PLSVC and bilateral superior vena cava in terms of accompanying anomalies and pregnancy outcomes. This was a retrospective study of the fetuses diagnosed with single and/or bilateral SVC at a tertiary fetal medicine center during 8 years. We detected 16 cases of single PLSVC and 84 cases of bilateral SVC. We found an association between the PLSVC and cardiac and extracardiac anomalies. Comparison between single PLSVC and BSVC cases revealed significant differences in the occurrence of heterotaxy and right isomerism. The study highlights the importance of prenatal diagnosis in PLSVC cases. Isolated PLSVC with situs solitus may be considered a benign finding, but larger studies are needed to understand the clinical implications of PLSVC in relation to chromosomal anomalies. Routine screening protocols should include three-vessel and trachea views to detect PLSVC.

Highly accelerated, Dixon-based non-contrast MR angiography versus high-pitch CT angiography

OBJECTIVES

To compare a novel, non-contrast, flow-independent, 3D isotropic magnetic resonance angiography (MRA) sequence that combines respiration compensation, electrocardiogram (ECG)-triggering, undersampling, and Dixon water-fat separation with an ECG-triggered aortic high-pitch computed tomography angiography (CTA) of the aorta.

MATERIALS AND METHODS

Twenty-five patients with recent CTA were scheduled for non-contrast MRA on a 3 T MRI. Aortic diameters and cross-sectional areas were measured on MRA and CTA using semiautomatic measurement tools at 11 aortic levels. Image quality was assessed independently by two radiologists on predefined aortic levels, including myocardium, proximal aortic branches, pulmonary veins and arteries, and the inferior (IVC) and superior vena cava (SVC). Image quality was assessed on a 5-point Likert scale.

RESULTS

All datasets showed diagnostic image quality. Visual grading was similar for MRA and CTA regarding overall image quality (0.71), systemic arterial image quality (p = 0.07-0.91) and pulmonary artery image quality (p = 0.05). Both readers favored MRA for SVC and IVC, while CTA was preferred for pulmonary veins (all p < 0.05). No significant difference was observed in aortic diameters or cross-sectional areas between native MRA and contrast-enhanced CTA (p = 0.08-0.94).

CONCLUSION

The proposed non-contrast MRA enables robust imaging of the aorta, its proximal branches and the pulmonary arteries and great veins with image quality and aortic diameters and cross-sectional areas comparable to that of CTA. Moreover, this technique represents a suitable free-breathing alternative, without the use of contrast agents or ionizing radiation. Therefore, it is especially suitable for patients requiring repetitive imaging.

Absent Superior Vena Cava: An Uncommon Cause of Anomalous Systemic Venous Return

We report a case of a one-year-old boy with tetralogy of Fallot, who was preoperatively diagnosed to have an associated systemic venous anomaly. Computed tomography confirmed the absent superior vena cava, and the case was managed with an appropriate cannulation strategy. Preoperative diagnosis and thorough planning of this rather benign anomaly were imperative for the successful outcome of this case. Clinical and surgical implications of this anomaly are discussed in this report.

Safety and efficacy of catheter ablation of para-Hisian accessory pathway via a direct superior vena cava approach: A multicenter study

BACKGROUND

Radiofrequency (RF) catheter ablation of para-Hisian accessory pathways (APs) can be challenging due to proximity to the conduction system.

METHODS

A total of 30 consecutive patients with para-Hisian AP were enrolled for ablation in three centers, 12 (40%) of whom had previously failed attempted ablation from the inferior vena cava (IVC) approach. Ablation was preferentially performed using a superior approach from the superior vena cava (SVC) in all patients.

RESULTS

The para-Hisian AP was eliminated from the SVC approach in 28 of 30 (93.3%) patients. In the remaining two patients, additional ablation from IVC was required to successfully eliminate the AP. There were two patients experienced reversible complete atrial-ventricular block and PR prolongation during the first RF application. Long-term freedom from recurrent arrhythmia was achieved in 29 (96.7%) patients over a mean follow-up duration of 15.6 ± 4.6 months.

CONCLUSION

Catheter ablation of para-Hisian AP from above using a direct SVC approach is both safe and effective, and should be considered especially in patients who have failed conventional ablation attempts from IVC approach.

Bidirectional Glenn operation without cardiopulmonary bypass: Single center experience and results

BACKGROUND

The bidirectional Glenn (BDG) shunt operation serves as temporary surgery for the treatment of single-ventricle physiology with the eventual Fontan procedure. In some cases, the procedure can be performed without the support of a cardiopulmonary bypass (CPB) machine. In this study, we present the surgical outcomes of off-pump BDG operation with the use of a temporary veno-atrial shunt to decompress the superior vena cava (SVC) during clamping time.

METHODS

A cohort of 23 patients underwent off-pump BDG operations at Cardiovascular Center, E Hospital. All patients were operated on using a veno-atrial shunt to decompress the SVC.

RESULTS

Satisfactory results with mean oxygen saturation increased from 79.6 ± 11.2% to 87.2 ± 4.7%. The SVC clamping time was 14 ± 2.4 min (ranging from 12 to 21 min). Among 23 patients, only six patients required blood transfusion, 17 patients had BDG without blood transfusion. No neurological complications or deaths occurred after the surgery, and the post-operative period was uneventful.

CONCLUSIONS

The use of veno-atrial shunts to decompress SVC during off-pump BDG operation is safe with good surgical outcomes and can avoid the deleterious effects caused by CPB. It is easily reproducible, at low cost and economically effective.

Application of Electrocardiogram Localization during Peripherally Inserted Central Catheter Line Insertion into the Persistent Left Superior Vena Cava of Neonates

BACKGROUND

 Most neonates with persistent left superior vena cava (PLSVC) have no clinical symptoms or hemodynamic changes, and this anomaly is only found during cardiac catheterization, pacemaker implantation, or central venous catheterization. Electrocardiogram (ECG) localization is helpful for the application of the peripherally inserted central catheter (PICC) technique in neonates with PLSVC.

OBJECTIVE

 To explore the characteristic waveforms of the P wave when a PICC under ECG localization is applied in neonates with PLSVC.

STUDY DESIGN

 The observation and management strategies for the P wave changes during catheter insertion (CI) of two neonates with PLSVC admitted to our institution between January and July 2020, who underwent PICC line insertion, were summarized.

RESULTS

 The characteristic P wave changes in two children with a PICC line inserted via the PLSVC were observed. When a wide inverted P wave appeared on ECG, the catheter was immediately withdrawn by 0.5 cm, a bidirectional P wave gradually appeared and then disappeared. After that, the catheter was further withdrawn by 0.5 cm. After catheterization, the optimal position of the PICC was confirmed by X-ray photography and bedside B-ultrasound. The PICC line was removed as scheduled after indwelling for 18 and 29 days, respectively, in the two cases, and no PICC-related complications occurred during indwelling.

CONCLUSION

 The characteristic P wave changes on ECG during CI provide important clinical reference values for the application of the PICC technique under ECG localization in neonates with PLSVC.

KEY POINTS

· Electrocardiogram localization.. · Peripherally inserted central catheter.. · Persistent left superior vena cava..

The value of transthoracic echocardiography and chest X-ray in locating the tip of central venous catheter in dialysis patients: a comparative study with computed tomography imaging

To determine the tip position of the central venous catheter (CVC) in patients with dialysis, the guidelines recommend that it be determined using chest radiography (CXR) after catheterization, without fluoroscopy. However, some researchers have proposed that transthoracic echocardiography (TTE) can replace CXR, but this has not been widely adopted. This study aimed to determine which of the two aforementioned methods is more suitable for locating the tip position of the CVC. This prospective study included 160 patients who underwent hemodialysis at our hospital from March 2021 to December 2022. After inserting the CVC through the internal jugular vein, we used transthoracic echocardiography and CXR to determine the tip of the CVC and compared the results with those of computed tomography (CT). In the comparison between TTE and CXR for locating the CVC tip, we obtained three main findings. (1) TTE was associated with fewer misdiagnosed cases than CXR. (2) TTE provided higher sensitivity (similar sensitivity in position 2), specificity, positive/negative predictive values, and accuracy than CXR. (3) When comparing the receiver operating characteristic curves of TTE and CXR, the area under the curve (95% confidence interval) for the former was larger. Additionally, we made anatomical discoveries: the "hyperechoic triangle" recognized by TTE was equivalent to the entrance of the superior vena cava into the right atrium shown by transesophageal transthoracic echocardiography. TTE is more suitable than CXR as the first examination for CVC tip localization, as it improves diagnostic accuracy and reduces X-ray radiation damage.

Diagnostic Value of Contrast-Enhanced Ultrasonography for Catheter-Related Right Brachiocephalic Vein and Superior Vena Cava Lesions in Patients Undergoing Hemodialysis-A Pilot Study

OBJECTIVES

To evaluate the diagnostic efficacy of contrast-enhanced ultrasonography (CEUS) for detecting catheter-related right brachiocephalic vein (RBV) and superior vena cava (SVC) obstructions in patients undergoing hemodialysis (HD).

METHODS

From June 1, 2021 to December 31, 2022, we enrolled 80 patients undergoing HD who had used or were using a central venous catheter as vascular access. We evaluated the diagnostic efficacy of conventional ultrasonography and CEUS for identifying RBV and SVC obstructions and compared them with that of digital subtraction angiography (DSA). In the stratified analysis, the SVC was divided into the upper and lower segments. In total, we analyzed 240 central venous segments, including the RBV.

RESULTS

Among the RBV and SVC visualized by DSA, conventional ultrasonography and CEUS could visualize 67.92 and 100% of the vein segments, respectively; however, the lengths and diameters of the RBV and SVC were smaller than those recorded with DSA (P < .001). The diagnostic efficacy of CEUS for detecting catheter-related central venous obstruction was better than that of conventional ultrasonography, with a higher sensitivity (83.95 vs 41.98%), specificity (89.94 vs 53.46%), accuracy (87.92 vs 49.58%), and F1 score (82.42 vs 49.64%). CEUS showed good agreement (κ = 0.732) with DSA. In the stratified analyses, CEUS also showed higher sensitivity (83.93, 83.33, and 84.62%, respectively) and better agreement with DSA (κ = 0.635, 0.655, and 0.673, respectively) than conventional ultrasonography for detecting the RBV and the upper and lower segments of the SVC.

CONCLUSIONS

CEUS had high sensitivity and specificity in diagnosing catheter-related RBV and SVC obstructions.

A Novel Technique of Placing Desfibrillator Leads in Patients with Persistent Left Superior Vena Cava

Persistent left superior vena cava is the most common thoracic venous anomaly. It is usually asymptomatic, but it can make implanting intracardiac devices difficult.We present a novel technique to facilitate desfibrillator lead implantation in patients with persistent left superior vena cava and the absence of the right superior vena cava. We used a fixed-curve Selectra 3D 65-42 cm sheath (Biotronik), orienting it toward the tricuspid valve (TV) by rotating it counter-clockwise. During follow-up, the electrodes remained stable.Our technique was safe, simple, and feasible for patients with this complex venous anatomy.

Transcatheter Closure of Superior Sinus Venosus Defects

Superior sinus venosus defect is a communication between the right and left atrium located above the upper margin of the oval fossa, immediately inferior to the junction of the superior vena cava and the right atrium. It is systematically associated with partial anomalous pulmonary venous drainage, especially of the right upper pulmonary vein. Surgical repair has been the gold standard approach to close that defect. Introduced in 2014, percutaneous closure has gradually become a safe and effective alternative to surgery in carefully selected patients, although worldwide experience remains limited. This article provides an appraisal of the patients' selection process and a step-by-step description of the procedure as well as a comprehensive review of its outcomes.

Evaluation of Inferior and Superior Vena Cava and the Vena Cava Ratio in Growth Restricted Fetuses

OBJECTIVE

To evaluate the changes in the diameters of superior vena cava (SVC) and inferior vena cava (IVC) and to measure the ratio between SVC and IVC in growth-restricted fetuses and compare these results with normally grown fetuses.

METHODS

Twenty-three consecutive patients with fetal growth restriction (FGR) (Group I) and 23 pregnant gestational age-matched controls (Group II) between 24 and 37 weeks of gestation were enrolled in the study between January 2018 and October 2018. The diameter of the SVC and IVC from inner wall to inner wall was measured in all patients by sonographic examination. The ratio between the diameter of the SVC and IVC was also measured in each patient to eliminate the gestational age factor. We have named this ratio the "vena cava ratio" (VCR). All parameters were compared between the two groups.

RESULTS

The diameter of the SVC was significantly greater in the fetuses with FGR (2.6-7.7 [5.4]) than in controls (3.2-5.6 [4.1]; P = .002; P < .01). The diameter of the IVC was significantly less in the fetuses with FGR (1.6-4.5 [3.2]) than in controls (2.7-5 [3.7]; P = .035; P < .05). The VCR was between 1.1 and 2.3 and the median value was 1.8 in Group I. The VCR was between 0.8 and 1.7 and the median value was 1.2. VCR was significantly higher in fetuses with FGR (P = .001 P < .01).

CONCLUSION

This study shows that VCR is higher in fetuses with growth restriction. Further studies are needed to clarify the association between VCR and antenatal prognosis and postnatal results.

Absent right superior vena cava and persistent left superior vena cava: An incidental finding

A patient with Marfan syndrome undergoing Bentall operation was found to have an absent right superior vena cava and persistent left superior vena cava. The dilation of coronary sinus raised the suspicion of persistent left superior vena cava. The diagnosis was confirmed by agitated saline contrast echocardiography and computed tomography of the chest.

Giant right atrial aneurysm associated with persistent left cranial vena cava in a cat

A 10-month-old female spayed Scottish Fold was referred to cardiology for incidental radiographic cardiomegaly. Echocardiography was suspicious for a right atrial or right auricular aneurysm. The differential diagnosis also included peritoneal-pericardial diaphragmatic hernia, mass lesion (cyst, granuloma, or neoplasia), or cardiac malformation. A giant right atrial aneurysm associated with a persistent left cranial vena cava was subsequently confirmed with computed tomography.

Persistent left superior vena cava without right superior vena cava during fetal life

Enlarged coronary sinus detected during cardiac examination in the prenatal period is the first finding that raises suspicion for persistent left superior vena cava. In this report, a patient was presented who was referred with the prediagnosis of cor triatriatum sinister in the antenatal period and diagnosed with isolated persistent left superior vena cava (SVC).

Hypotensive patient with superior vena cava obstruction diagnosed using resuscitative transesophageal echocardiography

BACKGROUND

Superior vena cava syndrome (SVCS) is a malignancy-related emergency. It is caused by obstruction of blood flow in the superior vena cava (SVC) secondary to intraluminal thrombosis, external compression, or direct invasion of tumor.

CASE SUMMARY

A 49-year-old male presented to the emergency department (ED) with acute hypoxemic respiratory failure. He was intubated and treated as pneumonia. Post-intubation, he became hypotensive, requiring fluid resuscitation and inotropic support. Resuscitative transesophageal echocardiography (TEE) showed external compression by a lung mass and an intraluminal thrombus causing SVC obstruction. Computed tomography (CT) angiography was performed, and it confirmed the TEE findings. A provisional diagnosis of lung carcinoma was made, and he underwent endovascular therapy for rapid symptomatic relief.

DISCUSSION

This case report highlights the role of resuscitative TEE in evaluating a hypotensive patient with clinical suspicion of SVCS at the emergency department. TEE performed at the bedside could help to diagnose and demonstrate the pathology causing SVCS in this case. TEE allowed high-quality image acquisition and was able to overcome the limitation of transthoracic echocardiography (TTE). TEE should be considered as an alternative ED imaging modality in the management of SVCS.

LEARNING POINTS

Lattice-tip catheter for single-shot pulmonary vein isolation with pulsed field ablation

BACKGROUND

A compressible lattice-tip catheter designed for focal ablation using radiofrequency or pulsed-field energies has been recently described. The objective of this study is to describe a new lattice catheter designed for single-shot pulmonary vein isolation (PVI).

METHODS

This 8F catheter consists of a compressible lattice tip that is delivered over the wire and is expandable up to 34 mm (SpherePVI™, Affera Inc.). Pulsed field ablation (PFA) was applied from 6 elements using a biphasic waveform of microsecond scale (± 1.3-2.0 kV, 5 s per application). In 12 swine, the superior vena cava (SVC) and right superior pulmonary vein (RSPV) were targeted for isolation. Animals were survived for 12-24 h (n = 6) or 3 weeks (n = 6) for evaluation of short and long-term safety and efficacy parameters. PVI was evaluated immediately after ablation and at the terminal procedure. Ablation-related microbubbles were examined using intracardiac echocardiography and phrenic nerve function by pacing. The tissue was examined by histopathology.

RESULTS

In all 12 animals, PFA resulted in successful acute isolation of the SVC and RSPV using 2.8 ± 1.1 and 3.2 ± 1.2 applications per vein, respectively. After a survival period of 23 ± 5.9 days, all targeted veins remained isolated, and the level of isolation persisted without significant regression or expansion. In one animal, SVC isolation at the level of the right atrial appendage resulted in sinus node arrest. PFA did not affect phrenic nerve function, and it was associated with a few isolated bubbles formation.

CONCLUSIONS

In this pre-clinical study, a new expandable lattice catheter designed for single-shot PVI was able to achieve rapid and durable isolation.

Optimal prevention method of phrenic nerve injury in superior vena cava isolation: efficacy of high-power, short-duration radiofrequency energy application on the risk points

BACKGROUND OR PURPOSE

Superior vena cava isolation (SVCI) is widely performed adjunctively to atrial fibrillation (AF) ablation. Right phrenic nerve injury (PNI) is a complication of this procedure. The purpose of the study is to determine the optimal PNI prevention method in SVCI.

METHODS

A total of 1656 patients who underwent SVCI between 2009 and 2022 were retrospectively examined. PNI was diagnosed based on the diaphragm position and movement in the upright position on chest radiographs before and after SVCI.

RESULTS

With the introduction of various PN monitoring systems over the years, the incidence of SVCI-associated PNI has decreased. However, complete PNI avoidance has not been achieved. PNI incidence according to fluoroscopy-guided PN monitoring, high-output pace-guided, compound motor action potential-guided, and 3-dimensional electro-anatomical mapping (EAM) systems was 8.1% (38/467), 2.7% (13/476), 2.4% (4/130), and 2.8% (11/389), respectively. However, a high-power, short-duration (50 W/7 s) radiofrequency (RF) energy application only on PNI risk points tagged by a 3-dimensional EAM system completely avoids PNI (0%; 0 /160 since April 2021). PNI showed no symptoms and recovered within an average of 188 days post-SVCI, except for a few patients who required > 1 year.

CONCLUSIONS

Although PNI incidence decreased annually with the introduction of various monitoring systems, these monitoring systems did not prevent PNI completely. Most notably, the delivery of a high-power, short-duration RF energy only on risk points tagged by EAM prevented PNI completely. PNI recovered in all patients. The application of higher-power, shorter-duration RF energy on risk points tagged by EAM appears to be an optimal PNI prevention maneuver.

Normal variations of the superior vena cava and azygos venous system depiction by CT scan in the adult Thai population

BACKGROUND

Identification of normal variations to the thoracic central venous system anatomy is essential in radiological intervention and cardiothoracic surgery to prevent complications.

PURPOSE

To estimate the prevalence and pattern of normal variations of superior vena cava (SVC) and azygos venous system as well as factors associated with normal variations of SVC.

MATERIAL AND METHODS

Venous-phase chest CT of 1336 patients were retrospectively reviewed. Age, sex, and underlying disease were recorded. SVC diameter and cross-sectional area were measured to evaluate for associations with normal variations.

RESULTS

The prevalence of normal anatomical variations of SVC and azygos venous system were 0.3% and 1.5%, respectively. Duplicated SVC was the most common variations. The most common variation for the azygos venous system was the connection between the hemiazygos and accessory hemiazygos veins draining into the left brachiocephalic vein (12/1336 cases, 0.9%). The median (interquartile range [IQR]) cross-sectional area compared between normal SVC (297.2 mm2) and duplicated SVC (223.5 mm2) showed a statistically significant difference (P = 0.033).

CONCLUSION

This study determined the prevalence of rare normal variations of the azygos venous system, a connection between the hemiazygos and accessory hemiazygos veins draining into the left brachiocephalic vein. The prevalence of normal variations of the SVC and azygos venous system in the adult Thai population was similar with that of previous publications. Cross-sectional area was the only factor with a significant association with SVC variations.

Slittable sheath supported right ventricular pacing lead implantation in persistent left superior vena cava with absent right superior vena cava: a case report

BACKGROUND

Persistent left superior vena cava (PLSVC) is the most common variant of systemic venous drainage. In the absence of the right superior vena cava (RSVC), implantation of a right ventricular pacing lead may be challenging. Therefore specific implantation techniques and experiences in PLSVC are worth reporting.

CASE PRESENTATION

We present a case report of a 90-year-old Caucasian female patient with PLSVC during single chamber pacemaker implantation due to the third-degree atrioventricular block. With common implantation techniques, we did not even reach the right ventricle. Therefore slittable CPS Direct ™ Universal sheath was employed to overcome the acute angle from PLSVC to tricuspid valve and ensure more fixation stability for longer 100-cm right ventricular lead placement.

CONCLUSION

This case demonstrates safe implantation of 100-cm long right ventricular bipolar active fixation pacing lead using common slittable CPS Direct ™ Universal sheath after failed attempts with "C" and "J" stylet shaped electrode. This sheath provides different angle towards tricuspid valve and more fixation stability in patient with PLSVC and absent connection to right atrium.