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Chest Feb 2024Electromagnetic stimulation of the phrenic nerve induces diaphragm contractions, but no coils for clinical use have been available. We recently demonstrated the...
BACKGROUND
Electromagnetic stimulation of the phrenic nerve induces diaphragm contractions, but no coils for clinical use have been available. We recently demonstrated the feasibility of ventilation using bilateral transcutaneous noninvasive electromagnetic phrenic nerve stimulation (NEPNS) before surgery in lung-healthy patients with healthy weight in a dose-dependent manner.
RESEARCH QUESTION
Is NEPNS feasible in critically ill patients in an ICU setting?
STUDY DESIGN AND METHODS
This feasibility nonrandomized controlled study aimed to enroll patients within 36 h of intubation who were expected to remain ventilated for ≥ 72 h. The intervention group received 15-min bilateral transcutaneous NEPNS bid, whereas the control group received standard care. If sufficient, NEPNS was used without pressure support to ventilate the patient; pressure support was added if necessary to ventilate the patient adequately. The primary outcome was feasibility, measured as time to find the optimal stimulation position. Further end points were sessions performed according to the protocol or allowing a next-day catch-up session and tidal volume achieved with stimulation reaching only 3 to 6 mL/kg ideal body weight (IBW). A secondary end point was expiratory diaphragm thickness measured with ultrasound from days 1 to 10 (or extubation).
RESULTS
The revised European Union regulation mandated reapproval of medical devices, prematurely halting the study. Eleven patients (five in the intervention group, six in the control group) were enrolled. The median time to find an adequate stimulation position was 23 s (interquartile range, 12-62 s). The intervention bid was executed in 87% of patients, and 92% of patients including a next-day catch-up session. Ventilation with 3 to 6 mL/kg IBW was achieved in 732 of 1,701 stimulations (43.0%) with stimulation only and in 2,511 of 4,036 stimulations (62.2%) with additional pressure support. A decrease in diaphragm thickness was prevented by bilateral NEPNS (P = .034) until day 10.
INTERPRETATION
Bilateral transcutaneous NEPNS was feasible in the ICU setting with the potential benefit of preventing diaphragm atrophy during mechanical ventilation. NEPNS ventilation effectiveness needs further assessment.
TRIAL REGISTRY
ClinicalTrials.gov; No.: NCT05238753; URL: www.
CLINICALTRIALS
gov.
PubMed: 38403186
DOI: 10.1016/j.chest.2024.02.035 -
Clinical Cardiology Feb 2024Pulsed field ablation (PFA) has emerged as a novel non-thermal modality with highly myocardium-specific. However, the PFA catheter based on contact force (CF)-sensing...
BACKGROUND
Pulsed field ablation (PFA) has emerged as a novel non-thermal modality with highly myocardium-specific. However, the PFA catheter based on contact force (CF)-sensing has not been reported. The study aimed to evaluate the efficacy and safety of a novel CF-sensing PFA catheter.
METHODS
First, different CF (5, 15, 25, and 35 g) of the novel PFA catheter were evaluated on lesion dimensions during ablation on right and left ventricle in two pigs. Next, this catheter was further evaluated on four typical sites of superior vena cava (SVC), cavotricuspid isthmus (CTI), right superior pulmonary vein (RSPV), and right inferior pulmonary vein (RIPV) for atrial ablation in another six pigs. Electrical isolation was evaluated immediately after ablation and 30-day survival. Chronic lesions were assessed via histopathology after euthanasia. Acute and chronic safety outcomes were observed peri- and post-procedurally.
RESULTS
In ventricular ablation, increased CF from 5 to 15 g produced significantly greater lesion depth but nonsignificant increases from 15 to 35 g. In atrial ablation, the novel CF-sensing PFA deliveries produced an acute attenuation of local electrograms and formation of a continuous line of block in all 6 pigs. The ablation line remained sustained blockage at the 30-day survival period. The CF of SVC, CTI, RSPV, and RIPV was 9.4 ± 1.5, 14.5 ± 3.2, 17.2 ± 2.6, and 13.4 ± 2.8 g, respectively. Moreover, no evidence of damage to esophagus or phrenic nerve was observed.
CONCLUSION
The novel CF-sensing PFA catheter potentiated efficient, safe, and durable ablation, without causing damage to the esophagus or phrenic nerve.
Topics: Humans; Swine; Animals; Vena Cava, Superior; Catheter Ablation; Catheters; Heart Ventricles; Myocardium
PubMed: 38402563
DOI: 10.1002/clc.24220 -
JACC. Clinical Electrophysiology May 2024In treating atrial fibrillation, pulsed-field ablation (PFA) has comparable efficacy to conventional thermal ablation, but with important safety advantages: no...
BACKGROUND
In treating atrial fibrillation, pulsed-field ablation (PFA) has comparable efficacy to conventional thermal ablation, but with important safety advantages: no esophageal injury or pulmonary vein stenosis, and rare phrenic nerve injury. However, when PFA is delivered in proximity to coronary arteries using a pentaspline catheter, which generates a broad electrical field, severe vasospasm can be provoked.
OBJECTIVES
The authors sought to study the vasospastic potential of a focal PFA catheter with a narrower electrical field and develop a preventive strategy with nitroglycerin.
METHODS
During atrial fibrillation ablation, a focal PFA catheter was used for cavotricuspid isthmus ablation. Angiography of the right coronary artery (some with fractional flow reserve measurement) was performed before, during, and after PFA. Beyond no nitroglycerin (n = 5), and a few testing strategies (n = 8), 2 primary nitroglycerin administration strategies were studied: 1) multiple boluses (3-2 mg every 2 min) into the right atrium (n = 10), and 2) a bolus (3 mg) into the right atrium with continuous peripheral intravenous infusion (1 mg/min; n = 10).
RESULTS
Without nitroglycerin, cavotricuspid isthmus ablation provoked moderate-severe vasospasm in 4 of 5 (80%) patients (fractional flow reserve 0.71 ± 0.08). With repetitive nitroglycerin boluses, severe spasm did not occur, and mild-moderate vasospasm occurred in only 2 of 10 (20%). Using the bolus + infusion strategy, severe and mild-moderate spasm occurred in 1 and 3 of 10 patients (aggregate 40%). No patient had ST-segment changes.
CONCLUSIONS
Ablation of the cavotricuspid isthmus using a focal PFA catheter routinely provokes right coronary vasospasm. Pretreatment with high doses of parenteral nitroglycerin prevents severe spasm.
Topics: Humans; Atrial Fibrillation; Nitroglycerin; Coronary Vasospasm; Male; Middle Aged; Female; Catheter Ablation; Aged; Vasodilator Agents; Coronary Angiography; Coronary Vessels
PubMed: 38385916
DOI: 10.1016/j.jacep.2023.12.015 -
Europace : European Pacing,... Mar 2024Pulmonary vein isolation (PVI) is a well-established strategy for the treatment of paroxysmal atrial fibrillation (PAF). Despite randomized controlled trials and...
Long-term outcomes of the pentaspline pulsed-field ablation catheter for the treatment of paroxysmal atrial fibrillation: results of the prospective, multicentre FARA-Freedom Study.
AIMS
Pulmonary vein isolation (PVI) is a well-established strategy for the treatment of paroxysmal atrial fibrillation (PAF). Despite randomized controlled trials and real-world data showing the promise of pulsed-field ablation (PFA) for this treatment, long-term efficacy and safety data demonstrating single-procedure outcomes off antiarrhythmic drugs remain limited. The aim of the FARA-Freedom Study was to evaluate the long-term efficacy and safety of PFA using the pentaspline catheter for PAF.
METHODS AND RESULTS
FARA-Freedom, a prospective, non-randomized, multicentre study, enrolled patients with PAF undergoing de novo PVI with PFA, who were followed for 12 months with weekly transtelephonic monitoring and a 72-h Holter ECG at 6 and 12 months. The primary safety endpoint was a composite of device- or procedure-related serious adverse events out to 7 days post-ablation and PV stenosis or atrioesophageal (AE) fistula out to 12 months. Treatment success is a composite of acute PVI and chronic success, which includes freedom from any documented atrial tachyarrhythmia longer than 30 s, use of antiarrhythmic drugs or cardioversion after a 3-month blanking period, or use of amiodarone or repeat ablation at any time. The study enrolled 179 PAF patients (62 ± 10 years, 39% female) at 13 centres. At the index procedure, all PVs were successfully isolated with the pentaspline PFA catheter. Procedure and left atrial dwell times, with a 20-min waiting period, were 71.9 ± 17.6 and 41.0 ± 13.3 min, respectively. Fluoroscopy time was 11.5 ± 7.4 min. Notably, monitoring compliance was high, with 88.4 and 90.3% with weekly events and 72-h Holter monitors, respectively. Freedom from the composite primary effectiveness endpoint was 66.6%, and 41 patients had atrial tachyarrhythmia recurrence, mostly recurrent atrial fibrillation (31 patients). The composite safety endpoint occurred in two patients (1.1%), one tamponade and one transient ischaemic attack. There was no coronary spasm, PV stenosis, or AE fistula. There were four cases of transient phrenic nerve palsy, but all resolved during the index procedure.
CONCLUSION
In this prospective, non-randomized, multicentre study, PVI using a pentaspline PFA catheter was effective in treating PAF patients despite rigourous endpoint definitions and high monitoring compliance and demonstrated favourable safety.
REGISTRATION
Clinical Trials.gov Identifier: NCT05072964 (sponsor: Boston Scientific Corporation).
Topics: Female; Humans; Male; Anti-Arrhythmia Agents; Atrial Fibrillation; Catheter Ablation; Constriction, Pathologic; Fistula; Prospective Studies; Pulmonary Veins; Recurrence; Tachycardia; Treatment Outcome; Middle Aged; Aged
PubMed: 38385529
DOI: 10.1093/europace/euae053 -
The Journal of Physiology Mar 2024Viscerosensory information travels to the brain via vagal afferents, where it is first integrated within the brainstem nucleus tractus solitarii (nTS), a critical...
Viscerosensory information travels to the brain via vagal afferents, where it is first integrated within the brainstem nucleus tractus solitarii (nTS), a critical contributor to cardiorespiratory function and site of neuroplasticity. We have shown that decreasing input to the nTS via unilateral vagus nerve transection (vagotomy) induces morphological changes in nTS glia and reduces sighs during hypoxia. The mechanisms behind post-vagotomy changes are not well understood. We hypothesized that chronic vagotomy alters cardiorespiratory responses to vagal afferent stimulation via blunted nTS neuronal activity. Male Sprague-Dawley rats (6 weeks old) underwent right cervical vagotomy caudal to the nodose ganglion, or sham surgery. After 1 week, rats were anaesthetized, ventilated and instrumented to measure mean arterial pressure (MAP), heart rate (HR), and splanchnic sympathetic and phrenic nerve activity (SSNA and PhrNA, respectively). Vagal afferent stimulation (2-50 Hz) decreased cardiorespiratory parameters and increased neuronal Ca measured by in vivo photometry and in vitro slice imaging of nTS GCaMP8m. Vagotomy attenuated both these reflex and neuronal Ca responses compared to shams. Vagotomy also reduced presynaptic Ca responses to stimulation (Cal-520 imaging) in the nTS slice. The decrease in HR, SSNA and PhrNA due to nTS nanoinjection of exogenous glutamate also was tempered following vagotomy. This effect was not restored by blocking excitatory amino acid transporters. However, the blunted responses were mimicked by NMDA, not AMPA, nanoinjection and were associated with reduced NR1 subunits in the nTS. Altogether, these results demonstrate that vagotomy induces multiple changes within the nTS tripartite synapse that influence cardiorespiratory reflex responses to afferent stimulation. KEY POINTS: Multiple mechanisms within the nucleus tractus solitarii (nTS) contribute to functional changes following vagal nerve transection. Vagotomy results in reduced cardiorespiratory reflex responses to vagal afferent stimulation and nTS glutamate nanoinjection. Blunted responses occur via reduced presynaptic Ca activation and attenuated NMDA receptor expression and function, leading to a reduction in nTS neuronal activation. These results provide insight into the control of autonomic and respiratory function, as well as the plasticity that can occur in response to nerve damage and cardiorespiratory disease.
Topics: Rats; Male; Animals; Solitary Nucleus; Rats, Sprague-Dawley; Neurons; Vagotomy; Vagus Nerve; Glutamic Acid
PubMed: 38377124
DOI: 10.1113/JP285854 -
Current Opinion in Cardiology May 2024This review addresses the evolving intersection of sleep-disordered breathing (SDB) and heart failure, a topic of increasing clinical significance due to the high... (Review)
Review
PURPOSE OF REVIEW
This review addresses the evolving intersection of sleep-disordered breathing (SDB) and heart failure, a topic of increasing clinical significance due to the high prevalence of SDB in heart failure patients and its impact on morbidity and mortality. It reflects recent advancements in diagnostic methodologies and therapeutic strategies. It emphasizes the need for heightened awareness among healthcare providers about the complex relationship between SDB and various forms of heart failure.
RECENT FINDINGS
Recent studies underscore the high incidence of SDB in heart failure patients, varying with the cause of heart failure. Emerging diagnostic tools, including home sleep tests and advanced inpatient screening methods, have improved the early detection and accurate diagnosis of SDB. Novel treatment modalities, like hypoglossal and phrenic nerve stimulation, are promising, especially where conventional therapies are inadequate. The review also discusses the complexities of managing SDB in the context of different heart failure subtypes.
SUMMARY
Findings from recent literature suggest that improved screening, diagnosis, and innovative treatment of SDB in heart failure patients can reduce morbidity, mortality, and healthcare costs. This review emphasizes the need for personalized treatment approaches tailored to individual patient profiles, highlighting the potential of new technologies and multidisciplinary strategies in clinical practice.
Topics: Humans; Sleep Apnea Syndromes; Heart Failure
PubMed: 38375816
DOI: 10.1097/HCO.0000000000001125 -
Clinical Research in Cardiology :... Feb 2024Cryoballoon (CB) ablation has become a popular method for pulmonary vein isolation (PVI) in atrial fibrillation (AF) treatment. This study aimed to compare the...
INTRODUCTION
Cryoballoon (CB) ablation has become a popular method for pulmonary vein isolation (PVI) in atrial fibrillation (AF) treatment. This study aimed to compare the intraprocedural ablation characteristics of two cryoballoons, Arctic Front Advance Pro™ (AFA-Pro, Medtronic) and POLARx™ (Boston Scientific).
METHODS AND RESULTS
In this retrospective single-center study, 230 symptomatic paroxysmal or persistent AF patients underwent CB ablation with either AFA-Pro or POLARx. Propensity-score matching resulted in two cohorts of 114 patients each. Baseline and procedural characteristics were comparable between both CBs. POLARx achieved lower minimal temperatures (e.g., left superior pulmonary vein, LSPV: AFA-Pro - 49.0 °C vs. POLARx - 59.5 °C) and lower temperatures at time-to-isolation (TTI). Additionally, POLARx reached lower temperatures faster, as evidenced by lower temperatures after 40 and 60 s, and a larger mean temperature change between 20 and 40 s. POLARx also had a greater area under the curve below 0 °C and a longer thawing phase. Both CBs achieved comparable high rates of final PV-isolation. TTI, minimal esophagus temperature, and first-pass isolation rates were similar between groups. Periprocedural complications, including phrenic nerve injuries, were comparable. Troponin levels in the left atrium were elevated with both systems. Values and change in troponin were numerically higher in the POLARx group (delta troponin: AFA-Pro 36.3 (26.4, 125.4) ng/L vs. POLARx 104.9 (49.5, 122.2) ng/L), p = 0.077).
CONCLUSION
AFA-Pro and POLARx are both highly effective and safe CB systems for PVI. POLARx exhibited significant faster and lower freezing characteristics, and numerically higher troponin levels might indicate greater myocardial injury. However, these differences did not translate into improved performance, procedural efficiency, or safety.
PubMed: 38358420
DOI: 10.1007/s00392-024-02398-2 -
Molecular Neurobiology Feb 2024β2-Adrenoceptors (β2-ARs) are the most abundant subtype of adrenergic receptors in skeletal muscles. Their activation via a stabilization of postsynaptic architecture...
β2-Adrenoceptors (β2-ARs) are the most abundant subtype of adrenergic receptors in skeletal muscles. Their activation via a stabilization of postsynaptic architecture has beneficial effects in certain models of neuromuscular disorders. However, the ability of β2-ARs to regulate neuromuscular transmission at the presynaptic level is poorly understood. Using electrophysiological recordings and fluorescent FM dyes, we found that β2-AR activation with fenoterol enhanced an involvement of synaptic vesicles in exocytosis and neurotransmitter release during intense activity at the neuromuscular junctions of mouse diaphragm. This was accompanied by an improvement of contractile responses to phrenic nerve stimulation (but not direct stimulation of the muscle fibers) at moderate-to-high frequencies. β2-ARs mainly reside in lipid microdomains enriched with cholesterol and sphingomyelin. The latter is hydrolyzed by sphingomyelinases, whose upregulation occurs in many conditions characterized by muscle atrophy and sympathetic nerve hyperactivity. Sphingomyelinase treatment reversed the effects of β2-AR agonist on the neurotransmitter release and synaptic vesicle recruitment to the exocytosis during intense activity. Inhibition of G protein with pertussis toxin completely prevented the sphingomyelinase-mediated inversion in the β2-AR agonist action. Note that lipid raft disrupting enzyme cholesterol oxidase had the same effect on β2-AR agonist-mediated changes in neurotransmission as sphingomyelinase. Thus, β2-AR agonist fenoterol augmented recruitment and release of synaptic vesicles during intense activity in the diaphragm neuromuscular junctions. Sphingomyelin hydrolysis inversed the effects of β2-AR agonist on neurotransmission probably via switching to G protein-dependent signaling. This phenomenon may reflect a dependence of the β2-AR signaling on lipid raft integrity in the neuromuscular junctions.
PubMed: 38353924
DOI: 10.1007/s12035-024-03991-2 -
Costoclavicular Brachial Plexus Block Facilitates Painless Upper Extremity Reduction: A Case Report.Clinical Practice and Cases in... Nov 2023The costoclavicular brachial plexus block (CCBPB) has emerged as a more effective approach to regional anesthesia of the upper extremity. The costoclavicular space is...
INTRODUCTION
The costoclavicular brachial plexus block (CCBPB) has emerged as a more effective approach to regional anesthesia of the upper extremity. The costoclavicular space is the anterior portion of the superior thoracic aperture, located between the clavicle and first rib. The brachial plexus cords traverse this space clustered together in a superficial location lateral to the axillary artery and share a consistent topographical relationship to one another. By targeting the brachial plexus at this specific anatomical location, the CCBPB offers a powerful, single-shot, sensorimotor block of the upper extremity below the shoulder. We present a novel application of the CCBPB to facilitate emergency department (ED) analgesia and closed reduction of an upper extremity fracture.
CASE REPORT
A 25-year-old male presented to the ED with a traumatic Colles fracture sustained during a high-speed motor vehicle collision. Despite multimodal analgesia, the patient reported intractable severe pain with intolerance of radial manipulation. An ultrasound-guided CCBPB was performed to augment pain control and avoid procedural sedation, resulting in dense, surgical anesthesia of the upper extremity, and painless fracture reduction.
CONCLUSION
Regional anesthesia is an effective component of multimodal pain management and another tool in the emergency physician's analgesic armamentarium. In acute orthopedic traumas necessitating emergent reduction, regional blocks serve as rescue pain control and can obviate the need for procedural sedation. In terms of targeted upper extremity analgesia, the CCBPB offers effective, single-shot, sensorimotor blockade below the shoulder, mitigating use of opioids and their deleterious side effects, while simultaneously avoiding incomplete blockade or phrenic nerve palsy associated with other approaches to brachial plexus blockade.
PubMed: 38353188
DOI: 10.5811/cpcem.59091 -
Cureus Jan 2024Although phrenic nerve and esophageal injury are commonly known risks associated with cryoablation, there is limited literature regarding coronary artery spasm (CAS), a...
Although phrenic nerve and esophageal injury are commonly known risks associated with cryoablation, there is limited literature regarding coronary artery spasm (CAS), a serious and potentially fatal complication of cryoablation. We report the case of a 68-year-old Caucasian female who developed a left main CAS with a significant hemodynamic compromise during cryoablation. The patient, with a history of hyperlipidemia, hypertension, and symptomatic persistent atrial fibrillation, was admitted for elective catheter ablation for atrial fibrillation. During the ablation of the left superior pulmonary vein (LSPV), the patient developed severe hypotension and bradycardia. The patient's monitor revealed ST elevation, confirmed by a 12-lead ECG. Immediate coronary angiography revealed the left main coronary spasm, which improved with nitroglycerine administration with resolution of ST elevation and return of the patient's hemodynamics to stability. The patient's left main CAS was induced by cryoablation of LSPV. Literature on atrial fibrillation ablation-induced CAS is scant, but a Japanese study has shown that it occurs more commonly in cryoablation than in radiofrequency, hot balloon, or laser ablation. The study showed LSPV as the most common site of ablation right before the spasms happened. Further studies about this topic are needed to delineate further the risk factors and the precautions that could prevent CAS. In the meantime, prompt recognition and appropriate intervention are critical for a good patient outcome.
PubMed: 38333489
DOI: 10.7759/cureus.51902