Low-load blood-flow-restriction resistance training (LL-BFR-RT) is gaining popularity, but its physiological effects remain unclear. This study aimed to compare LL-BFR-RT with low-load resistance exercise (LL-RT) and high-load resistance exercise (HL-RT) on metabolism, electrolytes, and ions in the lower extremities by invasive catheter measurements, which are crucial for risk assessment. Ten healthy men (27.6 ± 6.4 years) completed three trials of knee-extensor exercises with LL-RT (30% 1RM), LL-BFR-RT (30% 1RM, 50% limb occlusion pressure), and HL-RT (75% 1RM). The exercise protocol consisted of four sets to voluntary muscle failure with 1 min of rest between sets. Blood gas analysis was collected before, during, and after each trial through intravenous catheters at the exercising leg. LL-BFR-RT had lower total workload (1274 ± 237 kg, mean ± SD) compared to LL-RT (1745 ± 604 kg), and HL-RT (1847 ± 367 kg, p < 0.01), with no difference between LL-RT and HL-RT. Pain perception did not differ significantly. Exercise-induced drop in oxygen partial pressure, lactate accumulation and electrolyte shifts (with increased [K+]) occurred during under all conditions (p < 0.001). Creatine kinase and lactate dehydrogenase increased significantly 24- and 48-h postexercise under all three conditions (p < 0.001). This study, using invasive catheter measurements, found no significant differences in metabolic, ionic, and electrolyte responses among LL-BFR-RT, LL-RT, and HL-RT when exercised to voluntary muscular failure. LL-BFR-RT reduced time to failure without specific physiological responses.

Pediatric venous occlusions are a growing cause of morbidity and mortality, especially in hospitalized patients. Catheter-directed recanalization is a safe and effective treatment option in appropriately selected patients. Benefits of catheter directed therapies (CDTs) include the prevention of pulmonary embolism and end organ failure acutely as well as superior vena cava syndrome and post-thrombotic syndrome chronically. Timely diagnosis, recognition of underlying factors for thrombosis, and familiarity with the spectrum of tools and techniques for CDT are essential to optimizing outcomes in the acute setting. Recanalization of chronic venous occlusions can similarly provide symptomatic relief and achieve long term vessel patency. This review will detail the scope, techniques, and outcomes for CDT in the treatment of acquired systemic deep vein occlusions.

Multiple methods are used to tackle ipsilateral obstructed venous access in patients undergoing a device upgrade by implanting a new left ventricular lead. One feasible solution to tackle this is implantation of the upgrade lead contralaterally with pre-sternal tunnelization to the opposite side under conscious sedation.

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BACKGROUND: Blood flow restriction resistance exercise studies often require caffeine abstinence to avoid cardiovascular effects that could change the blood flow restriction stimulus. However, effects may be attenuated for habituated users.
OBJECTIVE: To compare cardiovascular responses to blood flow restriction resistance exercise when habituated users consume or abstain from caffeine.
METHODS: Thirty participants completed a 3-visit within-subject study beginning with familiarization and caffeine intake questionnaire.
METHODS: Visits 2 and 3 consisted of blood flow restriction resistance exercise (3 sets bicep curls to failure, 30% 1-repetition max, 40% arterial occlusion pressure [AOP]), following participants\' normal caffeine consumption (CAFF) or abstaining (ABS). AOP, systolic (SBP) and diastolic (DBP) blood pressure, and heart rate were measured preexercise and postexercise. Prevalues and preexercise to postexercise change scores for SBP, DBP, AOP (all millimeters of mercury), heart rate (in beats per minute), and repetitions were compared between conditions. Results are represented as mean (SD).
RESULTS: Preexercise AOP was similar for CAFF (137.8 [14.4]) and ABS (137.1 [14.9], BF10 = 0.2), although pre-SBP was higher for CAFF (115.4 [9.8]) than ABS (112.3 [9.4], BF10 = 1.9). Pre-DBP was similar between conditions. The exercise-induced change in AOP was greater for CAFF (18.4 [11.2]) than ABS (13.2 [14.9]), though evidence was anecdotal (BF10 = 0.7). Exercise-induced changes in SBP, DBP, and heart rate were similar between conditions (all BF10 ≤ 0.40). More repetitions were completed for CAFF (63 [26]) than ABS (57 [17], BF10 = 2.1).
CONCLUSIONS: The findings of this study suggest that for habituated users, maintaining daily caffeine habits will not have substantial effects on common cardiovascular variables relevant to blood flow restriction.

BACKGROUND: The ability of computed tomography (CT) characteristics to predict the difficulty of transvenous lead extraction (TLE) is an evolving subject.
OBJECTIVE: To identify CT characteristics associated with increased TLE difficulty.
METHODS: All consecutive patients undergoing TLE at the University of California San Diego from January 2018 to February 2022 were analyzed, utilizing the UC San Diego Lead Extraction Registry. Patients underwent cardiac-gated chest CT scans with intravenous contrast; all scans were reviewed by a single radiologist. Lead extraction was performed per standard institutional protocol with the initial use of a laser sheath and crossover to a mechanical sheath as needed. Multivariable linear and logistic regression analyses were performed to identify predictors of individual lead-removal fluoroscopy time and mechanical sheath use, as markers of extraction difficulty.
RESULTS: A total of 343 patients were analyzed. The mean age of the study population was 63.8 ± 15.4 years; 71% were male. The mean lead dwell-in duration was 8.6 ± 5.7 years. In multivariable linear regression analysis, venous occlusion detected on CT was independently associated with higher individual lead-removal fluoroscopy time (p = 0.004), when adjusting for clinical characteristics such as lead dwell time. In multivariable logistic regression analysis, calcification and venous occlusion were independently associated with a higher need for mechanical sheath use during TLE (odds ratio:5.08, p < 0.001, 95% CI: 2.54-10.46) and (odds ratio:3.72, p < 0.001, 95% CI: 1.89-7.35), respectively.
CONCLUSIONS: In patients undergoing TLE, venous occlusion identified by chest CT is associated with increased fluoroscopy time. Patients with lead-associated calcification or venous occlusion detected by chest CT are each five and three times more likely to require crossover from laser to a mechanical sheath.

Transcatheter sinus venosus defect (SVD) closure with covered stents is emerging as an alternative to surgery. An adequate anchor zone in the superior vena cava is mandatory for the stability of the covered stent to prevent caudal embolization. There is a potential risk of innominate vein occlusion by the fabric of the covered stent in patients with a very short superior caval vein. Three among a total of 105 patients who underwent SVD closure at our institution developed innominate vein occlusion. Predisposing anatomical factors, identification and management of occluded innominate vein, and follow-up outcomes are discussed.

UNASSIGNED: The purpose was to analyze the technical, clinical, and survival outcomes of our patients with malignant superior cava vein syndrome (SVCS) treated with endovascular approach and analyze the efficacy of different stent types used.
UNASSIGNED: It is an observational, retrospective, single-center study. From 2006 to 2023, 42 patients (32 male, 10 female, mean age 62 years, age range, 41-87 years) underwent percutaneous stent placement for malignant SVCS. One stainless steel stent (Wallstent) and 2 venous nitinol stent type (Sinus-XL, Venovo) were used. Follow-up mean was 276 days.
UNASSIGNED: A total of 53 stents were deployed. Clinical success was 97.6% in less 24 hours. Technical success was achieved in 97.6%. No complications were found except 1 patient died during the procedure due to stent migration and atrial dissociation (2.3%). Overall intraprocedural stent migration rate was 11.9% (18.8% stainless steel stent, 9.6% nitinol stent, p>0.05). Overall survival rates were 87.8%, 41.99%, and 34.12%, and overall primary patency rates were 100%, 93.3%, 91.6% at 1, 6, and 12 months, respectively.
UNASSIGNED: Endovascular treatment is a safe and effective therapeutic option for SVCS with high technical and clinical success rates and low complication and recurrence rates.
CONCLUSIONS: The malignant superior cava vein syndrome is a rare clinical entity treated classically with radiation and chemotherapy with a slower response, or surgical bypass, which is an aggressive surgical technique. Endovascular treatment offers a low-invasive technique with quick clinical resolution and good permeability results. However, further studies are lacking to deal with procedure technical characteristics, stent type used, technical complications, and medium- and long-term patency studies. This study aims to evaluate all these items, analysing self-expanding stainless steel and nitinol venous bare metal stents, and add value to endovascular treatment, confirming the good results of this technique.

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BACKGROUND: Management of transvenous leads in patients with congenital heart disease (CHD) can be complicated by venous obstructions and residual shunts. We present our experience performing concurrent lead extraction and dilation/stenting of venous pathways, including patients with complete venous obstruction.
METHODS: All cases of concurrent lead extraction and recanalization of vena cavae/baffles between 2017 and 2021 at Boston Children\'s Hospital were retrospectively included and reviewed for safety and efficacy.
RESULTS: Eight patients, 4 female, median 38.5 years of age (range 16.7-49 years) and 81.6 kg weight (range 41.3-97.8 kg) at time of procedure were included. All patients had CHD, a majority (n = 7) having transposition of the great arteries palliated via atrial switch. All leads were removed in their entirety, with most patients having two leads extracted (n = 7). Median lead dwell time was 13.8 years (range 3.6-35.3 years). Three patients had complete obstructions, three required stenting of their innominate veins and three required recanalization of their femoral vessels. Median procedure time was 9.8 h (range 5.4-12.8 h). Complications included blood transfusion (n = 2), arrhythmia (n = 3), pleural effusion (n = 1), and pressure ulcer (n = 1). There were no cardiac perforations, venous tears, or deaths.
CONCLUSIONS: Lead extraction along with dilation and stenting of venous anomalies, though long in duration, proved effective with minimal complications. This combined procedure can safely and effectively resolve complete obstructions secondary to transvenous leads.