Role and mechanism of lncRNA under magnetic nanoparticles in atrial autonomic nerve remodeling during radiofrequency ablation of recurrent atrial fibrillation.

It aimed to investigate the mechanism of magnetic nanoparticles (MNPs) on atrial fibrillation and effect of n-isopropyl acrylamide coated MNPs (NIPA-co-MN) on the treatment of atrial fibrillation. Ten beagles weighing 20 - 25 kg were randomly divided into test group and control group. Dogs with atrial fibrillation were set as test group, and non-atrial fibrillation dogs as control group. The expression of long non-coding RNA (lncRNA) differentially expressed in the right anterior adipose pad in atrial fibrillation and non-atrial fibrillation dogs was detected by high-throughput sequencing. The relationship between lncRNA and cardiac autonomic nerve remodeling (CANR) was explored. In addition, 20 beagles weighing 20-25 kg were selected to study the therapeutic effect of n-isopropylacrylamide magnetic nanoparticles (NIPA-co-MN) on atrial fibrillation, and statistical analysis was performed. The volume and number of new neurons in the anterior right fat pad of atrium of test group were larger than the control group. The test group dogs produced 45 brand-new lncRNA, including 15 up-regulated transcripts and 30 down-regulated transcripts. MNPs injection can slow down the reduction of ventricular rate in right inferior ganglion plexus. The anterior right ganglion plexus resulted in a reduced amplitude of sinus tachyarrhythmia. This study provided references for the discovery of new diagnostic biomarkers or therapeutic targets and for the treatment of patients with atrial fibrillation.

Effect of 28-mm Cryoballoon Ablation on Major Atrial Ganglionated Plexi.

OBJECTIVES: The authors intended to investigate if 28-mm cryoballoon (CB) ablation also modifies the 4 major atrial ganglionaated plexi (GP). BACKGROUND: The major atrial GP facilitate the initiation and maintenance of atrial fibrillation (AF). The 28-mm CB covers a large surface area of the left atrium and probably the GP areas. METHODS: High-frequency stimulation (20 Hz) was delivered to the area of anterior right GP (ARGP), inferior right GP, superior left (SLGP), and inferior left GP (ILGP). Positive GP sites were defined as a prolongation of R-wave to R-wave (RR) interval during AF by >50%. The area of each GP before and after CB ablation was compared. RESULTS: A total of 18 patients with paroxysmal AF who underwent CB and radiofrequency ablation and had positive GP sites were reviewed. The Wilcoxon signed-rank test was used to assess the effects of CB ablation on each GP. There was a statistically significant difference in the area of all 4 GP after CB ablation: 1) ARGP area: 2.9 cm2 (interquartile range [IQR]: 2.1 to 3.5 cm2) pre-CB, 0.1 cm2 (IQR: 0 to 0.6 cm2) post-CB, p = 0.0002; 2) inferior right GP area: 2.1 cm2 (IQR: 0.9 to 2.9 cm2) pre-CB, 0.5 cm2 (IQR: 0 to 1.7 cm2) post-CB, p = 0.001; 3) SLGP area: 1.4 cm2 (IQR: 0.6 to 2.4 cm2) pre-CB, 0 cm2 (IQR: 0 to 0 cm2) post-CB, p = 0.0002; and 4) ILGP area: 1.3 cm2 (IQR: 0.3 to 2.2 cm2) pre-CB, 0.3 cm2 (IQR: 0 to 1.6 cm2) post-CB, p = 0.008. CONCLUSIONS: The surface area of all 4 of the major atrial GP was substantially reduced by CB ablation. The SLGP and ARGP had the largest, whereas the ILGP had the least percent of reduction following CB ablation. Part of the therapeutic effects of CB ablation may result from modifying the 4 major atrial GP.

Comparison of renal artery, soft tissue, and nerve damage after irrigated versus nonirrigated radiofrequency ablation.

BACKGROUND: The long-term efficacy of radiofrequency ablation of renal autonomic nerves has been proven in nonrandomized studies. However, long-term safety of the renal artery (RA) is of concern. The aim of our study was to determine if cooling during radiofrequency ablation preserved the RA while allowing equivalent nerve damage. METHODS AND RESULTS: A total of 9 swine (18 RAs) were included, and allocated to irrigated radiofrequency (n=6 RAs, temperature setting: 50°C), conventional radiofrequency (n=6 RAs, nonirrigated, temperature setting: 65°C), and high-temperature radiofrequency (n=6 RAs, nonirrigated, temperature setting: 90°C) groups. RAs were harvested at 10 days, serially sectioned from proximal to distal including perirenal tissues and examined after paraffin embedding, and staining with hematoxylin-eosin and Movat pentachrome. RAs and periarterial tissue including nerves were semiquantitatively assessed and scored. A total of 660 histological sections from 18 RAs were histologically examined by light microscopy. Arterial medial injury was significantly less in the irrigated radiofrequency group (depth of medial injury, circumferential involvement, and thinning) than that in the conventional radiofrequency group (P<0.001 for circumference; P=0.003 for thinning). Severe collagen damage such as denatured collagen was also significantly less in the irrigated compared with the conventional radiofrequency group (P<0.001). Nerve damage although not statistically different between the irrigated radiofrequency group and conventional radiofrequency group (P=0.36), there was a trend toward less nerve damage in the irrigated compared with conventional. Compared to conventional radiofrequency, circumferential medial damage in highest-temperature nonirrigated radiofrequency group was significantly greater (P<0.001). CONCLUSIONS: Saline irrigation significantly reduces arterial and periarterial tissue damage during radiofrequency ablation, and there is a trend toward less nerve damage.

Application of heat- and steam-generating sheets to the lumbar or abdominal region affects autonomic nerve activity.

Effects of applying a heat- and steam-generating (HSG) sheet on peripheral hemodynamics and autonomic nerve activity were examined. An HSG sheet was applied to the lumbar or abdominal region. Measurements included skin temperature at the lumbar and abdominal regions and the fingertip, total hemoglobin, tissue oxygen saturation ratio (StO2), pupillary light reflex, changes in ECG R-R interval blood pressure and percutaneous electrogastrography (EGG). A heat-generating sheet without steam was used as the control. Based on the present findings, application of the HSG sheet to the lumbar or abdominal region may improve peripheral hemodynamics and inhibit sympathetic nerve activity, resulting in parasympathetic nerve activity dominance.

[Late manifestation of radiation injury to the plexus brachialis and plexus lumbosacralis]. / Spätmanifestation von Strahlenschäden am Plexus brachialis und Plexus lumbosacralis.

Radiotherapy of breast cancer, cervical cancer, testicular tumours and lymphoma is one of the most effective therapy options. Damage to the nervous system, in particular the brachial and lumbar plexus, is rare and typically leads to development of progressive sensory disturbances and motor weakness after years-long latency. We present two cases exemplifying the diagnostic problems in differentiating between radiation-induced injury and recurrence of the primary tumour. A clinical course with sensorimotor symptoms and signs progressing over months, electomyographic recording of myokymic discharges, and absence of a space-occupying mass suggest late-onset radiation-induced plexopathy. The literature on pathogenesis and incidence of radiation-induced plexopathy is reviewed.