BACKGROUND: Venovenous extracorporeal membrane oxygenation (V-V ECMO) has become an important treatment for severe pneumonia, but there are various complications during the treatment. This article describes a case with severe pneumonia successfully treated by V-V ECMO, but during treatment, the retrovenous catheter, which was supposed to be in the right internal vein, entered the superior vena cava directly in the mediastinum. The ECMO was safely withdrawn after multidisciplinary consultation. Our experience with this case is expected to provide a reference for colleagues who will encounter similar situations.
METHODS: A 64-year-old man had severe pulmonary infection and respiratory failure. He was admitted to our hospital and was given ventilation support (fraction of inspired oxygen 100%). The respiratory failure was not improved and he was treated by V-V ECMO, during which the venous return catheter, which was supposed to be in the right internal vein, entered the superior vena cava directly in the mediastinum. There was a risk of massive mediastinal bleeding if the catheter was removed directly when the ECMO was withdrawn. Finally, the patient underwent vena cava angiography + balloon attachment + ECMO withdrawal in the operating room (prepared for conversion to thoracotomy for vascular exploration and repair at any time during surgery) after multidisciplinary consultation. ECMO was safely withdrawn, and the patient recovered and was discharged.
CONCLUSIONS: Patients may have different vascular conditions. Multidisciplinary cooperation can ensure patient safety. Our experience will provide a reference for similar cases.

OBJECTIVE: Data about whether empirical superior vena cava (SVC) isolation (SVCI) improves the success rate of paroxysmal atrial fibrillation (PAF) are conflicting. This study sought to first investigate the characteristics of SVC-triggered atrial fibrillation and secondly investigate the impact of electroanatomical mapping-guided SVCI, in addition to circumferential pulmonary vein isolation (CPVI), on the outcome of PAF ablation in the absence of provoked SVC triggers.
RESULTS: A total of 130 patients undergoing PAF ablation underwent electrophysiological studies before ablation. In patients for whom SVC triggers were identified, SVCI was performed in addition to CPVI. Patients without provoked SVC triggers were randomized in a 1:1 ratio to CPVI plus SVCI or CPVI only. The primary endpoint was freedom from any documented atrial tachyarrhythmias lasting over 30 s after a 3-month blanking period without anti-arrhythmic drugs at 12 months after ablation. Superior vena cava triggers were identified in 30 (23.1%) patients with PAF. At 12 months, 93.3% of those with provoked SVC triggers who underwent CPVI plus SVCI were free from atrial tachyarrhythmias. In patients without provoked SVC triggers, SVCI, in addition to CPVI, did not increase freedom from atrial tachyarrhythmias (87.9 vs. 79.6%, log-rank P = 0.28).
CONCLUSIONS: Electroanatomical mapping-guided SVCI, in addition to CPVI, did not increase the success rate of PAF ablation in patients who had no identifiable SVC triggers.
BACKGROUND: ChineseClinicalTrials.gov: ChiCTR2000034532.

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.
CONCLUSIONS: 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.

This study summarizes the clinical data of patients who developed sternotomy hemorrhage during redo aortic surgery and analyzes the clinical experience of using hypothermic circulatory arrest.
We retrospectively analyzed the medical records of patients who developed sternotomy hemorrhage during redo aortic surgery from May 2018 to August 2021. General anesthesia with single-lumen tracheal intubation was used. Femoral artery, vein, and superior vena cava cannulation were used if cardiopulmonary bypass was required according to the situation, and right superior vein or apical cannulation was selected for left heart drainage.
A total of 11 patients were enrolled in this study, comprising nine males and two females, with an average age of 44.3±16.7 years. All cases were successfully completed without cerebrovascular complications or paraplegia. Two patients died during hospitalization, two patients died during the follow-up after discharge, and the remaining patients are recovering well.
The femoral-femoral bypass with hypothermic circulatory arrest technique is a safe and reliable method to use in cases of sternotomy hemorrhage during redo aortic surgery.

To investigate the optimal range of quantitative ablation index (AI) value during superior vena cava (SVC) electrical isolation by radiofrequency catheter ablation (RFCA).
First, in a development cohort of patients with atrial fibrillation (AF), the RFCA with 40 W was performed to complete SVC isolation guided by the conduction breakthrough point from the right atrium to SVC. Then, the range of AI value was calculated by offline analysis on different segments of SVC. Lastly, for the validation of AF patients, the safety and effectiveness of SVC isolation with the optimized target range of AI value were evaluated with an additional adenosine test.
A total of 101 patients with AF were included in the study (44 patients in the development cohort/57 in the validation cohort). The segmental ablation strategy was applied in 70% of the patients. According to the offline analysis of the AI values in the development cohort, the target AI value range was set as 350-400. The success rate of SVC isolation in the validation cohort was significantly higher than that in the exploration cohort (100% vs. 90.9%, p = .02), and no complications occurred in the exploration cohort. During the adenosine test, the recovery rate of electrical conduction in SVC was significantly lower than that in the pulmonary vein (3.5% vs. 17.5%).
The target AI value with a range from 350 to 400 is safe and effective for high-power RFCA to complete SVC isolation.

Superior vena cava (SVC) stenosis is rarely caused by iatrogenic trauma. Herein, the case of a 5-year-old boy who underwent radiofrequency ablation for paroxysmal supraventricular tachycardia but developed SVC stenosis and related syndromes is reported. Notably, the child exhibited an enlarged left atrial appendage that had partially breached the pericardium. Subsequent interventions involved successful removal of the stenosis, artificial vascular reconstruction, and comprehensive radiofrequency ablation of the entire right atrium, along with ligation of the left atrial appendage under direct vision. As a result, the child experienced relief from symptoms.

Paroxysmal atrial fibrillation originates most commonly in the pulmonary veins. However, the superior vena cava has proved to be arrhythmogenic in some cases. Pulsed field ablation, an emerging ablation technology, selectively affects myocardial tissue. Herein, we present a case of paroxysmal atrial fibrillation in a 64-year-old man who was admitted to our hospital for pulsed field ablation. The tachycardia was recurrent despite four successful pulmonary vein isolations. The superior vena cava was determined to be involved in arrhythmogenesis. The atrial fibrillation terminated immediately after the pulsed field ablation discharge at the superior vena cava.

Oliguric patients with acute kidney injury (AKI) often requires an internal jugular vein or femoral venous catheter to establish vascular access for emergency hemodialysis. Puncture with catheterization (PC) of the right internal jugular vein (RIJV) is relatively simple and is often the first choice for hemodialysis catheters insertion. However, complications such as bleeding and hematoma at the puncture site can occur, and in rare cases, the hemodialysis catheter (HDC) can be misplaced into the internal carotid artery, subclavian artery, subclavian vein, or even the thoracic cavity and mediastinum, leading to intractability for processing next. In this study, we report a case of an elderly female patient with AKI who underwent RIJV puncture for long-term HDC because her renal function had not recovered in the short term, and the lower end of the catheter penetrated the superior vena cava (SVC) into the mediastinum due to operator\'s carelessness. We did not perform open surgery or endovascular interventions, and instead, the HDC was retained in that place for four weeks and then directly removed without surgery. The patient did not experience any problems, such as bleeding or hematoma, and has been receiving hemodialysis from femoral catheter subsequently since then.

UNASSIGNED: Pulmonary vein isolation (PVI) is the standard ablation strategy for treating atrial fibrillation (AF). However, the optimal strategy of a repeat procedure for PVI non-responders remains unclear.
UNASSIGNED: This study aims to investigate the incidence of PVI non-responders in patients undergoing a repeat procedure, as well as the predictors for the recurrence of repeat ablation.
UNASSIGNED: A total of 276 consecutive patients who underwent repeat ablation from August 2016 to July 2019 in two centers were screened. A total of 64 (22%) patients with durable PVI were enrolled. Techniques such as low voltage zone modification, linear ablation, non-PV trigger ablation, and empirical superior vena cava (SVC) isolation were conducted.
UNASSIGNED: After the 20.0 ± 9.9 month follow-up, 42 (65.6%) patients were free from atrial arrhythmias. A significant difference was reported between the recurrent and non-recurrent groups in non-paroxysmal AF (50 vs. 23.8%, p = 0.038), diabetes mellitus (27.3 vs. 4.8%, p = 0.02), and empirical superior vena cava (SVC) isolation (28.6 vs. 60.5%, p = 0.019). Multivariate regression analysis demonstrated that empirical SVC isolation was an independent predictor of freedom from recurrence (95% CI: 1.64-32.8, p = 0.009). Kaplan-Meier curve demonstrates significant difference in recurrence between empirical and non-empirical SVC isolation groups (HR: 0.338; 95% CI: 0.131-0.873; p = 0.025).
UNASSIGNED: About 22% of patients in repeat procedures were PVI non-responders. Non-paroxysmal AF and diabetes mellitus were associated with recurrence post-re-ablation. Empirical SVC isolation could potentially improve the outcome of repeat procedures in PVI non-responders.

OBJECTIVE: The purpose of this study is to evaluate the preliminary safety and effect of a pulsed electric field (PEF) ablation system.
METHODS: The pulmonary veins (PVs) and superior vena cava (SVC) were isolated with the pulsed field ablation (PFA) system, which included a PEF generator and an electrode. The effects of PFA were investigated in six porcines using a novel circular catheter with combined functions (mapping/ablation) designed to work with a cardiac mapping system. The PEF generator delivered a train of biphasic pulsed electric pulses with a high amplitude (800-2000 V) and short pulse duration. The voltage mapping, PVs and SVC potentials, ostial diameters, and phrenic nerve and esophagus viability data were collected 4 weeks later, after which the animals were subsequently euthanized for gross histopathology analysis.
RESULTS: PFA 100% isolated the PVs and SVC with four applications with a mean pulse number of 100-150 pulses, causing no muscle convulsion. PFA does not cause PV stenosis or phrenic nerve dysfunction. Histological analysis confirmed 100% transmurally without any venous stenoses or phrenic injuries. Pathology follow-up showed that PFA had selectively ablated cardiomyocytes but spared blood vessels, the esophagus, and phrenic nerves; after ablation, the myocardial tissue showed homogeneous fibrosis.
CONCLUSIONS: The PFA system is safe and feasible in the preliminary porcine model, which can effectively isolate PVs and SVCs. Transmural tissue damage can be achieved without phrenic palsy or stenosis.