-
Anatolian Journal of Cardiology Jun 2024Superior vena cava (SVC) is atrial fibrillation (AF)'s most common non-pulmonary vein (PV) foci. Studies reported conflictory results when SVC isolation (SVCi) was...
BACKGROUND
Superior vena cava (SVC) is atrial fibrillation (AF)'s most common non-pulmonary vein (PV) foci. Studies reported conflictory results when SVC isolation (SVCi) was combined with PVi and long-term outcomes were lacking. Therefore, we aimed to evaluate the long-term efficacy and safety of empirical SVCi as an adjunct to cryoballoon-based PV isolation (PVi) in persistent AF ablation.
METHODS
A total of 40 consecutive persistent AF patients (60.6 ± 8.2 years, 52.5% females) who underwent SVCi in addition to PVi compared with a propensity score matched cohort of 40 persistent AF patients (58.6 ± 8.7 years, 50% female) in whom PVi-only was performed. Second-generation cryoballoon (CB2) was used in all procedures. Atrial tachyarrhythmia (ATa) recurrence was defined as the detection of AF, atrial flutter, or atrial tachycardia (≥30 s) after a 3-month blanking period.
RESULTS
Pulmonary veins and SVC were successfully isolated in all patients. At a mean of 46.7 ± 7.8 months follow-up, 22 (55%) patients in the PVi-only group, and 27 (67.5%) patients in the PVi + SVCi group were free of ATa after the index procedure (P =.359). Phrenic nerve injury (PNI) was detected in 2 (5%) patients in the PVi-only group (during right PVi) and 2 (5%) patients in the PVi + SVCi group (during SVCi) (P = 1.00). Cox regression analysis revealed that early recurrence was the only predictor of recurrence (hazard ratio 4.88, 95% confidence interval 1.59-14.96; P =.005).
CONCLUSION
Long-term results of our small sample-sized study revealed that CB-based PVi + SVCi was associated with outcomes similar to the PVi-only strategy in patients with persistent AF. Although complication rates were similar between the groups, close follow-up of diaphragmatic movement is crucial to prevent PNI during SVCi.
PubMed: 38832523
DOI: 10.14744/AnatolJCardiol.2024.4092 -
Journal of Clinical Medicine May 2024Atrial fibrillation, representing the most prevalent sustained cardiac arrhythmia, significantly impacts stroke risk and cardiovascular mortality. Historically managed... (Review)
Review
Atrial fibrillation, representing the most prevalent sustained cardiac arrhythmia, significantly impacts stroke risk and cardiovascular mortality. Historically managed with antiarrhythmic drugs with limited efficacy, and more recently, catheter ablation, the interventional approach field is still evolving with technological advances. This review highlights pulsed field ablation (PFA), a revolutionary technique gaining prominence in interventional electrophysiology because of its efficacy and safety. PFA employs non-thermal electric fields to create irreversible electroporation, disrupting cell membranes selectively within myocardial tissue, thus preventing the non-selective damage associated with traditional thermal ablation methods like radiofrequency or cryoablation. Clinical studies have consistently shown PFA's ability to achieve pulmonary vein isolation-a cornerstone of AF treatment-rapidly and with minimal complications. Notably, PFA reduces procedure times and has shown a lower incidence of esophageal and phrenic nerve damage, two common concerns with thermal techniques. Emerging from oncological applications, the principles of electroporation provide a unique tissue-selective ablation method that minimizes collateral damage. This review synthesizes findings from foundational animal studies through to recent clinical trials, such as the MANIFEST-PF and ADVENT trials, demonstrating PFA's effectiveness and safety. Future perspectives point towards expanding indications and refinement of techniques that promise to improve AF management outcomes further. PFA represents a paradigm shift in AF ablation, offering a safer, faster, and equally effective alternative to conventional methods. This synthesis of its development and clinical application outlines its potential to become the new standard in AF treatment protocols.
PubMed: 38792520
DOI: 10.3390/jcm13102980 -
Plastic and Reconstructive Surgery.... May 2024A 13-year-old girl with a painful left neck mass was referred to our institution due to suspicions of malignancy. The patient reported pain that accompanied her frequent...
A 13-year-old girl with a painful left neck mass was referred to our institution due to suspicions of malignancy. The patient reported pain that accompanied her frequent neck spasms. Computed tomography revealed a large, soft-tissue mass in the left neck, deep to the sternocleidomastoid. The lesion anteriorly displaced the internal carotid artery and both displaced and crushed the internal left jugular vein. Uniquely, a three-dimensional virtual reality model combining magnetic resonance imaging and computed tomography data was used to determine the lesion's resectability and visualize which structures would be encountered or require protection while ensuring total resection. During operation, we confirmed that the mass also laterally displaced the brachial plexus, cranial nerves X and XI, and spinal nerves C3-C5 (including the phrenic) of the cervical plexus. Postsurgical pathological analysis confirmed a diagnosis of desmoid tumor, also known as aggressive fibromatosis, whereas DNA sequencing revealed a mutation, a somatic genetic marker found in approximately 90% of desmoid tumor cases. When possible, the most widely used method for the treatment of desmoid tumors has been gross resection. Chemotherapy, radiotherapy, and local excision are also used in the treatment of fibromatoses when complete resection is judged infeasible. In this case, a complete surgical resection with tumor-free surgical margins was performed. A standard cervical approach with a modified posterolateral incision site was implemented to avoid a conspicuous anterior neck scar. No flap, nerve repair, or reconstruction was warranted. At 1 year of postsurgical follow-up, the patient showed minimal scarring and no signs of recurrence.
PubMed: 38784831
DOI: 10.1097/GOX.0000000000005763 -
Experimental Neurology Aug 2024Doxorubicin (DOX) is a highly effective anthracycline antibiotic used to treat a wide variety of cancers including breast cancer, leukemia and lymphoma. Unfortunately,...
Doxorubicin (DOX) is a highly effective anthracycline antibiotic used to treat a wide variety of cancers including breast cancer, leukemia and lymphoma. Unfortunately, clinical use of DOX is limited due to adverse off-target effects resulting in fatigue, respiratory muscle weakness and dyspnea. The diaphragm is the primary muscle of inspiration and respiratory insufficiency is likely the result of both muscle weakness and neural impairment. However, the contribution of neuropathology to DOX-induced respiratory muscle dysfunction is unclear. We hypothesized that diaphragm weakness following acute DOX exposure is associated with neurotoxicity and that exercise preconditioning is sufficient to improve diaphragm muscle contractility by maintaining neuromuscular integrity. Adult female Sprague-Dawley rats were randomized into four experimental groups: 1) sedentary-saline, 2) sedentary-DOX, 3) exercise-saline or 4) exercise-DOX. Endurance exercise preconditioning consisted of treadmill running for 1 h/day at 30 m/min for 10 days. Twenty-four hours after the last bout of exercise, animals were treated with DOX (20 mg/kg, I.P.) or saline (equal volume). Our results demonstrate that 48-h following DOX administration diaphragm muscle specific force is reduced in sedentary-DOX rats in response to both phrenic nerve and direct diaphragm stimulation. Importantly, endurance exercise preconditioning in DOX-treated rats attenuated the decrease in diaphragm contractile function, reduced neuromuscular transmission failure and altered phrenic nerve morphology. These changes were associated with an exercise-induced reduction in circulating biomarkers of inflammation, nerve injury and reformation. Therefore, the results are consistent with exercise preconditioning as an effective way of reducing respiratory impairment via preservation of phrenic-diaphragm neuromuscular conduction.
Topics: Animals; Diaphragm; Rats, Sprague-Dawley; Doxorubicin; Female; Rats; Physical Conditioning, Animal; Antibiotics, Antineoplastic; Synaptic Transmission; Phrenic Nerve; Muscle Contraction; Neuromuscular Junction
PubMed: 38782352
DOI: 10.1016/j.expneurol.2024.114818 -
Cardiovascular and Interventional... May 2024
PubMed: 38769207
DOI: 10.1007/s00270-024-03745-6 -
Respiratory Physiology & Neurobiology May 2024Shape and size of the nasopharyngeal airway is controlled by muscles innervated facial, glossopharyngeal, vagal, and hypoglossal cranial nerves. Contrary to brainstem...
Shape and size of the nasopharyngeal airway is controlled by muscles innervated facial, glossopharyngeal, vagal, and hypoglossal cranial nerves. Contrary to brainstem networks that drive facial, vagal and hypoglossal nerve activities (FNA, VNA, HNA) the discharge patterns and origins of glossopharyngeal nerve activity (GPNA) remain poorly investigated. Here, an in situ perfused brainstem preparation (n=19) was used for recordings of GPNA in relation to phrenic (PNA), FNA, VNA and HNA. Brainstem transections were performed (n=10/19) to explore the role of pontomedullary synaptic interactions in generating GPNA. GPNA generally mirrors FNA and HNA discharge patterns and displays pre-inspiratory activity relative to the PNA, followed by robust inspiratory discharge in coincidence with PNA. Postinspiratory (early expiratory) discharge was, contrary to VNA, generally absent in FNA, GPNA or HNA. As described previously FNA and HNA discharge was virtually eliminated after pontomedullary transection while an apneustic inspiratory motor discharge was maintained in PNA, VNA and GPNA. After brainstem transection GPNA displayed an increased tonic activity starting during mid-expiration and thus developed prolonged pre-inspiratory activity compared to control. In conclusion respiratory GPNA reflects FNA and HNA which implies similar function in controlling upper airway patency during breathing. That GPNA preserved its pre-inspiratory/inspiratory discharge pattern in relation PNA after pontomedullary transection suggest that GPNA premotor circuits may have a different anatomical distribution compared HNA and FNA and thus may therefore hold a unique role in preserving airway patency.
PubMed: 38768741
DOI: 10.1016/j.resp.2024.104281 -
Circulation. Arrhythmia and... May 2024Unlike conventional microsecond pulsed electrical fields that primarily target the cell membranes, nanosecond pulses are thought to primarily electroporate intracellular...
BACKGROUND
Unlike conventional microsecond pulsed electrical fields that primarily target the cell membranes, nanosecond pulses are thought to primarily electroporate intracellular organelles. We conducted a comprehensive preclinical assessment of catheter-based endocardial nanosecond pulsed field ablation in swine.
METHODS
A novel endocardial nanosecond pulsed field ablation system was evaluated in a total of 25 swine. Using either a low-dose (5-second duration) or high-dose (15-second duration) strategy, thoracic veins and discrete atrial and ventricular sites were ablated. Swine survived for <1 (n=1), ≈2 (n=7), ≈7 (n=6), 14 (n=2), or ≈28 (n=9) days, and venous isolation was assessed before euthanize. Safety assessments included evaluation of esophageal effects, phrenic nerve function, and changes in venous caliber. All tissues were subject to careful gross pathological and histopathologic examination.
RESULTS
All (100%) veins (13 low-dose, 34 high-dose) were acutely isolated, and all reassessed veins (6 low-dose, 15 high-dose) were durably isolated. All examined vein lesions (10 low-dose, 22 high-dose) were transmural. Vein diameters (n=15) were not significantly changed. Of the animals assessed for phrenic palsy (n=9), 3 (33%) demonstrated only transient palsy. There were no differences between dosing strategies. Thirteen mitral isthmus lesions were analyzed, and all 13 (100%) were transmural (depth, 6.4±0.4 mm). Ventricular lesions were 14.7±4.5 mm wide and 7.1±1.3 mm deep, with high-dose lesions deeper than low-dose (7.9±1.2 versus 6.2±0.8 mm; =0.007). The esophagus revealed nontransmural adventitial surface lesions in 5 of 5 (100%) animals euthanized early (2 days) post-ablation. In the 10 animals euthanized later (14-28 days), all animals demonstrated significant esophageal healing-8 with complete resolution, and 2 with only trace fibrosis.
CONCLUSIONS
A novel, endocardial nanosecond pulsed field ablation system provides acute and durable venous isolation and linear lesions. Transient phrenic injury and nontransmural esophageal lesions can occur with worst-case assessments suggesting limits to pulsed field ablation tissue selectivity and the need for dedicated assessments during clinical studies.
PubMed: 38758741
DOI: 10.1161/CIRCEP.124.012854 -
European Heart Journal. Case Reports May 2024Left ventricular (LV) summit arrhythmias account for up to 14% of LV arrhythmias. The ablation of LV summit arrhythmias is challenging, as testified by the fact that...
BACKGROUND
Left ventricular (LV) summit arrhythmias account for up to 14% of LV arrhythmias. The ablation of LV summit arrhythmias is challenging, as testified by the fact that radiofrequency (RF) catheter ablation failure is frequent. Retrograde coronary venous ethanol infusion has been proposed as an alternative approach for the ablation of LV summit arrhythmias.
CASE SUMMARY
A 47-year-old man with Lamin A/C cardiomyopathy was referred for the ablation of a pleiomorphic ventricular tachycardia (VT) storm, with dominant morphology compatible with LV summit origin. He first received a combined endo- and epicardial RF ablation with the elimination of three clinically relevant VTs. However, the dominant VT could not be ablated due to the proximity of the coronary vasculature and phrenic nerve and remained inducible. Accordingly, an urgent rescue redo procedure consisting of retrograde coronary venous ethanol ablation was performed. Based on the best pace-match and precocity, the first septal, retro-pulmonary branch and the first diagonal branch were infused with ethanol with immediate cessation of the tachycardia and non-inducibility. Anti-arrhythmic drugs were withdrawn, while guideline-directed medical therapy for heart failure was continued. No complications occurred. After 3 months, the patient remained free from any arrythmias.
DISCUSSION
Ablation of LV summit arrythmias is challenging, especially in the context of an electrical storm or in patients with structural heart disease. In such a situation, rescue ablation with retrograde coronary venous ethanol infusion represents an attractive alternative ablation modality.
PubMed: 38756545
DOI: 10.1093/ehjcr/ytae235 -
PolarX vs Arctic Front for Cryoballoon Ablation of Paroxysmal AF: The Randomized COMPARE CRYO Study.JACC. Clinical Electrophysiology Apr 2024Pulmonary vein isolation is an effective treatment for atrial fibrillation (AF). Cryoballoon ablation using the Arctic Front cryoballoon (Medtronic) was found to be...
BACKGROUND
Pulmonary vein isolation is an effective treatment for atrial fibrillation (AF). Cryoballoon ablation using the Arctic Front cryoballoon (Medtronic) was found to be superior to antiarrhythmic drug treatment. Recently, a novel cryoballoon system was introduced (PolarX, Boston Scientific).
OBJECTIVES
The purpose of this study was to compare the efficacy and safety of the 2 cryoballoons in a randomized controlled trial.
METHODS
Patients with symptomatic paroxysmal AF were enrolled in 2 centers and randomized 1:1 to pulmonary vein isolation using the PolarX or the Arctic Front cryoballoon. All patients received an implantable cardiac monitor. The primary endpoint was first recurrence of atrial tachyarrhythmia (AF, atrial flutter, or atrial tachycardia [AT]) between days 91 and 365. Procedural safety was assessed by a composite of tamponade, phrenic nerve palsy lasting >24 hours, vascular complications, stroke/transient ischemic attack, atrioesophageal fistula or death up to 30 days.
RESULTS
A total of 201 patients were enrolled. At 1 year, recurrence of atrial tachyarrhythmia had occurred in 41 of 99 patients (41.6%) assigned to the PolarX group and in 48 of 102 patients (47.1%) assigned to the Arctic Front group (HR: 0.85 [95% CI: 0.56-1.30]; P = 0.03 for noninferiority; P = 0.46 for superiority). The safety endpoint occurred in 5 patients (5%) in the PolarX group (n = 5 phrenic nerve palsies lasting >24 hours), whereas no safety endpoints occurred in the Arctic Front group (P = 0.03).
CONCLUSIONS
In this randomized controlled trial using implantable cardiac monitors for continuous rhythm monitoring, the novel PolarX cryoballoon was noninferior compared with the Arctic Front cryoballoon regarding efficacy. However, the PolarX balloon resulted in significantly more phrenic nerve palsies. (Comparison of PolarX and the Arctic Front Cryoballoons for PVI in Patients With Symptomatic Paroxysmal AF [COMPARE-CRYO]; NCT04704986).
PubMed: 38752963
DOI: 10.1016/j.jacep.2024.03.021 -
Experimental Neurology Aug 2024Low-dose (< 2 h/day), acute intermittent hypoxia (AIH) elicits multiple forms of serotonin-dependent phrenic motor plasticity and is emerging as a promising therapeutic...
Low-dose (< 2 h/day), acute intermittent hypoxia (AIH) elicits multiple forms of serotonin-dependent phrenic motor plasticity and is emerging as a promising therapeutic strategy to restore respiratory and non-respiratory motor function after spinal cord injury (SCI). In contrast, high-dose (> 8 h/day), chronic intermittent hypoxia (CIH) undermines some forms of serotonin-dependent phrenic motor plasticity and elicits pathology. CIH is a hallmark of sleep disordered breathing, which is highly prevalent in individuals with cervical SCI. Interestingly, AIH and CIH preconditioning differentially impact phrenic motor plasticity. Although mechanisms of AIH-induced plasticity in the phrenic motor system are well-described in naïve rats, we know little concerning how these mechanisms are affected by chronic SCI or intermittent hypoxia preconditioning. Thus, in a rat model of chronic, incomplete cervical SCI (lateral spinal hemisection at C2 (C2Hx), we assessed serotonin type 2A, 2B and 7 receptor expression in and near phrenic motor neurons and compared: 1) intact vs. chronically injured rats; and 2) the impact of preconditioning with varied "doses" of intermittent hypoxia (IH). While there were no effects of chronic injury or intermittent hypoxia alone, CIH affected multiple receptors in rats with chronic C2Hx. Specifically, CIH preconditioning (8 h/day; 28 days) increased serotonin 2A and 7 receptor expression exclusively in rats with chronic C2Hx. Understanding the complex, context-specific interactions between chronic SCI and CIH and how this ultimately impacts phrenic motor plasticity is important as we leverage AIH-induced motor plasticity to restore breathing and other non-respiratory motor functions in people with chronic SCI.
Topics: Animals; Male; Rats; Cervical Cord; Cervical Vertebrae; Chronic Disease; Hypoxia; Motor Neurons; Neuronal Plasticity; Phrenic Nerve; Rats, Sprague-Dawley; Receptors, Serotonin; Spinal Cord Injuries
PubMed: 38750949
DOI: 10.1016/j.expneurol.2024.114808