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Objectives: A novel temperature-controlled intravascular radiofrequency balloon angioplasty (RFBA) technique was designed and developed for atherosclerosis (AS) management. Methods: After establishing an AS model based on a balloon denudation injury of the abdominal aorta and a high cholesterol diet in rabbits, 46 animals were randomly assigned to the RFBA group (n = 28) or the plain balloon angioplasty (PBA) group (n = 28). The groups were further subdivided based on post-treatment euthanasia times (1 hour, 7 days, 14 days, and 28 days). Histopathological changes were observed by hematoxylin and eosin and Masson’s staining. Immunohistochemistry, western blotting, and real-time quantitative polymerase chain reaction were used to detect changes in pro-inflammatory, anti-inflammatory, and apoptotic factors; TGF-β/Smad-2 pathway protein Immune levels; and mRNA levels in tissues, respectively. Results: The vascular lumen area in the RFBA group was larger than that in the PBA group at the same time points, although the change in the vascular lumen area was not different between groups. The expression of Bax, TGF-β, Smad-2, and Caspase-3 in the RFBA group was significantly higher than that in the PBA group. The expression levels of Bcl-2 in the RFBA group were significantly lower than those in the PBA group. Conclusions: At 28 days, RFBA dilated the atherosclerotic blood vessels and thickened the fibrous cap of atherosclerotic plaques to promote plaque stability. RFBA was also found to activate apoptotic factors and the TGF-/Smad-2 inflammatory pathway.

Aims: This study aimed to characterize circular RNA (circRNA) profiles associated with atrial fibrosis-related atrial fibrillation (AF) and reveal critical circRNAs for AF. Methods: Sprague Dawley rats were randomly divided into control and atrial fibrosis-related AF groups (n = 15 in each group). The rats in the atrial fibrosis-related AF group were induced by chronic intermittent hypoxia (CIH), and then confirmed by electrocardiograms, echocardiography, hematoxylin-eosin staining, Masson staining, immunohistochemistry assays and western blotting. After that, the atrial tissues were sent for circRNA sequencing, and the differentially expressed circRNAs were identified and validated by quantitative real-time polymerase chain reaction (qRT-PCR). Finally, a series of cell experiments were performed to explore the roles of two crucial circRNAs in rat atrial fibroblasts. Results: A CIH-induced AF model was successfully established in the rats. After sequencing, five upregulated and 11 downregulated circRNAs were identified in the CIH-induced AF group. These dysregulated circRNAs were primarily associated with “carbohydrate metabolism” and “cardiovascular diseases”. Two circRNAs (circRNA_0263 and circRNA_1507) were predicted to regulate target gene expression by interacting with corresponding miRNAs, including rno-miR-29b-5p, rno-miR-29b-3p, rno-miR-496-5p, rno-miR-136-5p, and novel123-mature. Additionally, circRNA_0263 knockdown and circRNA_1507 overexpression inhibited the cell viability of fibroblasts, and downregulated the expression of fibrosis-related proteins. Conclusion: A series of circRNAs were identified as dysregulated in an AF rat model, and circRNA_0263 and circRNA_1507 might be crucial for atrial fibrosis-related AF development by competing with several miRNAs.

Discrete potentials (DPs) have been recorded and targeted as the site of ablation of the outflow tract arrhythmias. The aim of the present study was to investigate the significance of DPs with respect to mapping and ablation for idiopathic outflow tract premature ventricular contractions (PVCs) or ventricular tachycardias (VTs).Seventeen out of 24 consecutive patients with idiopathic right or left ventricular outflow tract PVCs/VTs who underwent radiofrequency catheter ablation between September 2012 and December 2013 in our department were included. Intracardiac electrograms during the mapping and ablation were analyzed.During sinus rhythm, sharp high-frequency DPs that displayed double or multiple components were recorded following or buried in the local ventricular electrograms in all of the 17 patients, peak amplitude was (0.51 ± 0.21) mV. The same potential was recorded prior to the local ventricular potential of the PVCs/VTs. Spontaneous reversal of the relationship of the DPs to the local ventricular electrogram was noted during the arrhythmias. The DPs were related to a region of low voltage showed by intracardiac high-density contact mapping. At the sites with DPs, unipolar and bipolar ventricular voltage of sinus beats were lower compared with the adjacent regions without DPs (unipolar: (6.1 ± 1.8) mV vs. (8.3 ± 2.3) mV, P0.05; bipolar: (0.62 ± 0.45) mV vs. (1.03 ± 0.60) mV, P0.05). The targeted DPs were still present in 12 patients after successful elimination of the ectopies. Discrete potentials were not present in seven controls.Discrete potentials and related low-voltage regions were common in idiopathic outflow tract ventricular arrhythmias. Discrete potential- and substrate-guided ablation strategy could help to reduce the recurrence of idiopathic outflow tract arrhythmias.