-
Journal of Neuroinflammation Feb 2024Sepsis has a high mortality rate due to multiple organ failure. However, the influence of peripheral inflammation on brainstem autonomic and respiratory circuits in...
BACKGROUND
Sepsis has a high mortality rate due to multiple organ failure. However, the influence of peripheral inflammation on brainstem autonomic and respiratory circuits in sepsis is poorly understood. Our working hypothesis is that peripheral inflammation affects central autonomic circuits and consequently contributes to multiorgan failure in sepsis.
METHODS
In an Escherichia coli (E. coli)-fibrin clot model of peritonitis, we first recorded ventilatory patterns using plethysmography before and 24 h after fibrin clot implantation. To assess whether peritonitis was associated with brainstem neuro-inflammation, we measured cytokine and chemokine levels in Luminex assays. To determine the effect of E. coli peritonitis on brainstem function, we assessed sympatho-respiratory nerve activities at baseline and during brief (20 s) hypoxemic ischemia challenges using in situ-perfused brainstem preparations (PBPs) from sham or infected rats. PBPs lack peripheral organs and blood, but generate vascular tone and in vivo rhythmic activities in thoracic sympathetic (tSNA), phrenic and vagal nerves.
RESULTS
Respiratory frequency was greater (p < 0.001) at 24 h post-infection with E. coli than in the sham control. However, breath-by-breath variability and total protein in the BALF did not differ. IL-1β (p < 0.05), IL-6 (p < 0.05) and IL-17 (p < 0.04) concentrations were greater in the brainstem of infected rats. In the PBP, integrated tSNA (p < 0.05) and perfusion pressure were greater (p < 0.001), indicating a neural-mediated pathophysiological high sympathetic drive. Moreover, respiratory frequency was greater (p < 0.001) in PBPs from infected rats than from sham rats. Normalized phase durations of inspiration and expiration were greater (p < 0.009, p < 0.015, respectively), but the post-inspiratory phase (p < 0.007) and the breath-by-breath variability (p < 0.001) were less compared to sham PBPs. Hypoxemic ischemia triggered a biphasic response, respiratory augmentation followed by depression. PBPs from infected rats had weaker respiratory augmentation (p < 0.001) and depression (p < 0.001) than PBPs from sham rats. In contrast, tSNA in E. coli-treated PBPs was enhanced throughout the entire response to hypoxemic ischemia (p < 0.01), consistent with sympathetic hyperactivity.
CONCLUSION
We show that peripheral sepsis caused brainstem inflammation and impaired sympatho-respiratory motor control in a single day after infection. We conclude that central sympathetic hyperactivity may impact vital organ systems in sepsis.
Topics: Rats; Animals; Escherichia coli; Inflammation; Brain Stem; Peritonitis; Sepsis; Fibrin; Ischemia
PubMed: 38331902
DOI: 10.1186/s12974-024-03025-7 -
Circulation. Arrhythmia and... Mar 2024Pulsed field ablation uses electrical fields to cause nonthermal cell death over several hours. Polarization-sensitive optical coherence reflectometry is an optical...
BACKGROUND
Pulsed field ablation uses electrical fields to cause nonthermal cell death over several hours. Polarization-sensitive optical coherence reflectometry is an optical imaging technique that can detect changes in the tissue ultrastructure in real time, which occurs when muscular tissue is damaged. The objective of this study was to evaluate the ability of a polarization-sensitive optical coherence reflectometry system to predict the development of chronic lesions based on acute changes in tissue birefringence during pulsed field ablation.
METHODS
Superior vena cava isolation was performed in 30 swine using a biphasic, bipolar pulsed field ablation system delivered with a nonirrigated focal tip catheter. Acute changes in tissue birefringence and voltage abatement were analyzed for each individual lesion. A high-resolution electroanatomical map was performed at baseline and 4 to 12 weeks after ablation to locate electrical gaps in the ablated area.
RESULTS
A total of 141 lesions were delivered and included in the analysis. Acute electrical isolation based on the electroanatomical map was achieved in 96% of the animals, but chronic isolation was only seen in 14 animals (46%). The mean voltage abatement of lesions that showed recovery was 82.8%±14.6% versus 84.4%±17.4% for those that showed fibrosis (=0.7). The mean acute reduction in tissue birefringence in points demonstrating fibrosis was 63.8%±11.3% versus 9.1%±0.1% in the points that resulted in electrical gaps. A threshold of acute reduction of birefringence of ≥20% could predict chronic lesion formation with a sensitivity of 96% and a specificity of 83%.
CONCLUSIONS
Acute tissue birefringence changes assessed with polarization-sensitive optical coherence reflectometry during pulsed field ablation can predict chronic lesion formation and guide the ablation procedure although limited by the tissue thickness.
Topics: Swine; Animals; Atrial Fibrillation; Catheter Ablation; Vena Cava, Superior; Thorax; Pulmonary Veins; Fibrosis; Treatment Outcome
PubMed: 38318720
DOI: 10.1161/CIRCEP.123.012255 -
Open Heart Feb 2024Assess safety and performance of novel quadripolar preshaped left ventricular (LV) leads: NAVIGO 4LV 2D ('S shaped') and NAVIGO 4LV ARC ('U shaped').
OBJECTIVES
Assess safety and performance of novel quadripolar preshaped left ventricular (LV) leads: NAVIGO 4LV 2D ('S shaped') and NAVIGO 4LV ARC ('U shaped').
METHODS
Patients indicated for cardiac resynchronisation therapy were enrolled in a multicentre, prospective, controlled study (NAVIGATOR, NCT03279484). Patients were implanted with either a NAVIGO 4LV 2D or ARC lead, and assessed at 10 weeks, 6, 12 and 24 months post-implant. Co-primary safety and performance endpoints were assessed at 10 weeks. Safety endpoint was the patients' rate free from lead-related complications. Performance endpoint was the rate of patients with successful lead performance, defined as LV pacing threshold ≤2.5 V at 0.5 ms on at least one pacing vector, and the absence of phrenic nerve stimulation at the final programmed configuration. Lead-related complications and electrical parameters were monitored throughout study.
RESULTS
A NAVIGO 4LV lead was successfully implanted in 211 out of 217 patients (97.2%). The safety endpoint was met, with 100% and 96.1% of patients free from complications for NAVIGO 4LV 2D and ARC, respectively. The performance endpoint was met with 98.1% and 98.9% of patients with a successful lead performance for NAVIGO 4LV 2D and ARC, respectively. Over 12 months, the global complication-free rate for both leads was 97.1% (95% CI: 93.71% to 98.70%), with a mean pacing capture threshold of 1.23 V±0.73 V and a mean impedance of 951 Ω±300.1 Ω.
CONCLUSION
A high implantation success rate and low complication rate was reported for the novel NAVIGO 4LV 2D and ARC leads, along with successful performance up to 12 months.
Topics: Humans; Prospective Studies; Heart Failure; Cardiac Resynchronization Therapy; Cardiac Resynchronization Therapy Devices; Electrodes, Implanted
PubMed: 38316493
DOI: 10.1136/openhrt-2023-002517 -
Journal of Orthopaedics May 2024Traumatic brachial plexus injuries (TBPIs) are debilitating and complex to treat. The last five decades have seen advances in surgical management, and consequently...
BACKGROUND
Traumatic brachial plexus injuries (TBPIs) are debilitating and complex to treat. The last five decades have seen advances in surgical management, and consequently improved functional outcomes in patients with these injuries. There is limited data available describing the outcomes of surgically managed TBPIs within the South African context. This study aimed to identify the common causes of injury, injury characteristics, and functional outcomes of surgically managed patients with TBPIs.
METHODS
We conducted a retrospective chart review of all adult patients that underwent surgery for TBPIs over a period of ten years at a specialised hand unit in South Africa. The minimum follow-up period was one year. Patient demographic details, injury characteristics and functional outcomes were collected. Statistical analysis was performed to determine factors associated with functional outcomes. A good functional outcome for recovery was defined as a Medical Research Council (MRC) grade of three or more for the affected elements of the plexus at the most recent follow-up.
RESULTS
Forty-seven patients of median age 32 years were included in the final analysis. Most patients were male (87.2 %). The majority of patients were injured in motor vehicle accidents (MVAs) or from penetrating stab wounds (48.9 % and 38.3 % respectively). The median pre-operative MRC grade of the affected elements of the brachial plexus was 0.0, and post-operatively was 2.0. Fourteen patients (14 of 47, 29.8 %) had a good outcome and 33 had a poor outcome (33 of 47, 70.2 %). There was no difference in outcome comparing penetrating injury mechanisms to closed traction or blunt injuries, (p = 0.386, OR 1.75, 95 % CI 0.49-6.20). All patients with pan-plexal injuries had a poor outcome (15 of 33, 46 %). All patients who received intercostal (6 of 33, 18 %) or phrenic nerve transfers (3 of 33, 9 %) had a poor outcome.
CONCLUSION
Adult traumatic BPIs in this South African sample typically presented more than two months after injury and were comprised of a high proportion of penetrating injuries. Just under a third of surgically managed patients had a good outcome. Pan plexal injuries have uniformly poor outcomes. We recommend early referral for all TBPIs to a unit that manages BPI to improve outcomes.
PubMed: 38313427
DOI: 10.1016/j.jor.2024.01.006 -
Journal of Nuclear Cardiology :... Jan 2024Diaphragmatic eventration is the elevation of hemi-diaphragm without any disruption to diaphragmatic continuity which can be congenital or acquired. The most common...
Diaphragmatic eventration is the elevation of hemi-diaphragm without any disruption to diaphragmatic continuity which can be congenital or acquired. The most common acquired cause is phrenic nerve paralysis due to traumatic causes and is usually incidentally diagnosed on chest radiograph or computed tomography. We hereby report a case of a patient who had road traffic accident with fracture of the left proximal femur. Stress Myocardial Perfusion Imaging (MPI) done for pre-operative clearance showed an incidental tracer avidity adjoining to left myocardium in the thorax. It was confirmed on anatomical imaging to be gastric cavity uptake due to diaphragm eventration.
PubMed: 38301802
DOI: 10.1016/j.nuclcard.2024.101817 -
Frontiers in Neurology 2023Respiratory muscle weakness with higher ventilatory demands were reported even in patients recovering from only mild COVID-19 symptoms. Aim of this study was to assess...
OBJECTIVES
Respiratory muscle weakness with higher ventilatory demands were reported even in patients recovering from only mild COVID-19 symptoms. Aim of this study was to assess the function of phrenic nerve and inspiratory respiratory muscle as well as cardiopulmonary exercise capacity in patients with prolonged exertional dyspnea after COVID-19 infection.
METHODS
In this observational exploratory study, electrophysiological examination of the phrenic nerve, inspiratory muscle capacity as well as lung function test, 6-min walk distance (6MWD) and cardiopulmonary exercise test, have been performed in 22 patients post COVID-19 diagnosis (post-CoV).
RESULTS
Exercise capacity (peak workload, Wpeak % predicted and peak oxygen uptake, VOpeak % predicted) were significantly affected in the post-CoV patients (61.8 ± 23.3 Wpeak % and 70.9 ± 22.3 VOpeak %). Maximum inspiratory pressure (MIP) was reduced (60.1 ± 25.5 mbar). In 6 of the 22 patients the electrophysiological response of the phrenic nerve was pathologically decreased (reduced compound muscle action potential, CMAP), while nerve conduction velocity (NCV) was normal, which corresponds to reduced muscle fiber contraction capacity. Positive relationships were demonstrated between 6MWD and MIP ( = 0.88) as well as quality of life questionnaire (CRQ) and MIP ( = 0.71) only in patients with reduced CMAP.
DISCUSSION
Respiratory muscle weakness and exercise capacity is associated with reduced phrenic nerve CMAP without signs of neuropathy. This indicates that muscle fiber pathology of the diaphragm may be one pathophysiological factor for the prolonged respiratory symptoms after COVID-19 infections.
PubMed: 38292031
DOI: 10.3389/fneur.2023.1308443 -
Netherlands Heart Journal : Monthly... Apr 2024Atrial fibrillation often necessitates catheter ablation when antiarrhythmic drug therapy fails. Single-shot technologies using thermal energy, such as cryoballoon...
INTRODUCTION
Atrial fibrillation often necessitates catheter ablation when antiarrhythmic drug therapy fails. Single-shot technologies using thermal energy, such as cryoballoon ablation, are commonly used, but pulsed field ablation (PFA), an innovative non-thermal ablation technique, is a potential alternative. This retrospective observational study aimed to compare the safety and efficacy of cryoballoon ablation and PFA in patients undergoing their first pulmonary vein isolation (PVI) procedure for atrial fibrillation treatment.
METHODS
We utilised real-world data from patients who underwent PVI using cryoballoon ablation or PFA. The primary outcome encompassed procedural complications, including phrenic nerve palsy, cardiac tamponade, thromboembolic complications, bleeding complications and mortality. Secondary outcomes were procedural characteristics including procedure duration, length of hospital admission, and re-do ablation rates within 6 months.
RESULTS
A total of 1714 procedures were analysed: 1241 in the cryoballoon group and 473 in the PFA group. Gender distribution (p = 0.03) and estimated glomerular filtration rate (p = 0.01) differed significantly. With regard to the primary outcome, the cryoballoon group demonstrated a higher incidence of phrenic nerve palsy compared with the PFA group (15 vs 0; p = 0.02). The procedure duration was shorter in the PFA group, even after adjusting for baseline characteristics (95.0 vs 74.0 min; p < 0.001). After adjustment for baseline characteristics, admission duration differed between the groups as well (p = 0.04).
CONCLUSION
The study results supported the safety and efficacy of PFA over cryoballoon ablation for PVI, highlighting advantages such as shorter procedure duration and absence of phrenic nerve palsy.
PubMed: 38291296
DOI: 10.1007/s12471-023-01850-8 -
Muscle & Nerve Mar 2024Retraction: Utility of phrenic nerve conduction studies for identification of patients with neuromuscular diseases requiring invasive mechanical ventilation. S....
Retraction: Utility of phrenic nerve conduction studies for identification of patients with neuromuscular diseases requiring invasive mechanical ventilation. S. Narukawa, K. Ishizuka, K. Sugimoto, K. Nomura. Muscle & Nerve 65, 211-216. https://doi.org/10.1002/mus.27449. The above article, published online on 28 October 2021 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the Editor-in-Chief Zachary Simmons, and Wiley Periodicals, Inc. The corresponding author informed the journal that there is an inconsistency between the time for which the clinical research reported in this article received approval and the time period in which the research was performed. The retraction has been agreed due to this violating the journal's requirements for ethical approval of clinical research involving human participants.
PubMed: 38287518
DOI: 10.1002/mus.28056 -
Journal of Surgical Case Reports Jan 2024A 41-year-old man developed phrenic nerve palsy after the resection of anterior mediastinal tumor, who underwent diaphragmatic resection with an endostapler. After the...
A 41-year-old man developed phrenic nerve palsy after the resection of anterior mediastinal tumor, who underwent diaphragmatic resection with an endostapler. After the surgery, the surgical stump ruptured, resulting in a large diaphragmatic defect with the liver prolapsing into the thoracic cavity. Then, the diaphragmatic defect was closed with a polytetrafluoroethylene (PTFE) patch. The diaphragm was reconstructed using a second PTFE patch overlaying the diaphragmatic defect that had been closed by the first PTFE patch, because solely patching the diaphragmatic defect had a risk of recurrence of diaphragmatic elevation due to remaining original diaphragm and the presence of phrenic nerve palsy. The second PTFE patch was fixed to the lower ribs by non-absorbable suture. The postoperative course was favorable. After 3 months, his symptoms and pulmonary function improved. We underwent double PTFE patch repair in a patient with both huge diaphragmatic defect and phrenic nerve palsy.
PubMed: 38283412
DOI: 10.1093/jscr/rjae005 -
Journal of Cardiovascular Development... Dec 2023Phrenic nerve injury is a devastating complication that results in significant morbidity and mortality. We developed a novel technique to localize the phrenic nerve and...
BACKGROUND
Phrenic nerve injury is a devastating complication that results in significant morbidity and mortality. We developed a novel technique to localize the phrenic nerve and evaluate its success.
METHODS
Two groups of children underwent repeat sternotomy for a variety of indications. Group I (69 patients, nerve stimulator) and Group II (78 patients, no nerve stimulator).
RESULTS
There was no significant difference in the mean age and weight between the two groups: (6.4 ± 6.5 years vs. 5.6 ± 6.4 years; = 0.65) and (25.2 ± 24.1 vs. 22.6 ± 22.1; = 0.69), respectively. The two groups were comparable in the following procedures: pulmonary conduit replacement, bidirectional cavopulmonary anastomosis, aortic arch repair, and Fontan, while Group I had more pulmonary arterial branch reconstruction ( = 0.009) and Group II had more heart transplant patients ( = 0.001). There was no phrenic nerve injury in Group I, while there were 13 patients who suffered phrenic nerve injury in Group II ( < 0.001). No early mortality in Group I, while five patients died prior to discharge in Group II. Eleven patients underwent diaphragm plication in Group II ( = 0.001). The mean number of hours on the ventilator was significantly higher in Group II (137.3 ± 324.9) compared to Group I (17 ± 66.9), < 0.001. Group II had a significantly longer length of ICU and hospital stays compared to Group I ( = 0.007 and = 0.006 respectively).
CONCLUSION
Phrenic nerve injury in children continues to be associated with significant morbidities and increased length of stay. The use of intraoperative phrenic nerve stimulator can be an effective way to localize the phrenic nerve and avoid its injury.
PubMed: 38248878
DOI: 10.3390/jcdd11010008