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Aims: This study aimed to investigate an appropriate catheter manipulation approach for ventricular arrhythmias (VAs) originating from the left ventricular epicardium adjacent to the transitional area from the great cardiac vein to the anterior interventricular vein (DGCV-AIV).Methods: A total of 123 patients with DGCV-AIV VAs were retrospectively analyzed. All these patients underwent routine mapping and ablation by conventional approach [Non-Swartz sheath support (NS) approach] firstly. In the situation of the distal portion of the coronary venous system (CVS) not being accessed or a good target site not being obtained, the Swartz sheath support (SS) approach was attempted alternatively. If this still failed, the hydrophilic coated guidewire and left coronary angiographic catheter-guided deep engagement of Swartz sheath in GCV to support ablation catheter was performed.Results: A total of 103 VAs (103/123, 83.74%) were successfully eliminated in DGCV-AIV. By NS approach, the tip of the catheter reached DGCV in 39.84% VAs (49/123), reached target sites in 35.87% VAs (44/123), and achieved successful ablation in 30.89% VAs (38/123), which was significantly lower than by SS approach (88.61% (70/79), 84.81 % (67/79), and 75.95% (60/79), P < 0.05). There were no significant differences in complication occurrence between the NS approach and the SS approach (4/123, 3.25% vs. 7/79, 8.86%, p > 0.05). The angle between DGCV and AIV <83° indicated an inaccessible AIV by catheter tip with a predictive value of 94.5%. Width/height of coronary venous system>0.69 more favored a SS approach with a predictive value of 87%.Conclusion: For radiofrequency catheter ablation (RFCA) of VAs arising from DGCV-AIV, the SS approach facilitates the catheter tip to achieve target sites and contributes to a successful ablation.

Objectives Histone deacetylase 4 (HDAC4)and histone deacetylase 5 (HDAC5) are two isoforms of class IIa HDACs, LMK235 is an HDAC inhibitor with higher selectivity forHDAC4/5. Here, we aimed to explorethe effects of LMK235 on ventricular remodelling after myocardial infarction (MI). Methods The MI model was established by left anterior descending branch ligation. The effects of LMK235 on cardiac dysfunction was determined by echocardiography and left ventricular pressure measurement. Fibrosis was evaluated by Masson staining and fibrotic biomarker expression, inflammation was evaluated by HE staining and inflammatory cytokine expression. In vitro, myofibroblast transformation was induced by transforming growth factor-β1 (TGF-β1) stimulation in primary mouse cardiac fibroblasts (MCFs), and macrophage polarization was induced by lipopolysaccharide (LPS) stimulation in RAW264.7 cells. Western blotting, immunofluorescence, flow cytometry were performed to examine the effects of LMK235. Key findings LMK235 ameliorated cardiac dysfunction post-MI by suppressing fibrosisand inflammation. In MCFs, LMK235 attenuated TGF-β1-induced fibrotic biomarker expression by inhibiting Smad2/3 pathway. In RAW264.7 cells, LMK235 attenuated LPS-induced inflammatory cytokine expression by inhibiting NF-κB pathway. Conclusions LMK235 can attenuate fibrosis post-MI by inhibiting Smad2/3 pathway in cardiac fibroblasts, and attenuate inflammation post-MI by inhibiting NF-κB pathway in macrophages, leading to improved cardiac function.

BACKGROUND For ventricular arrhythmias (VAs) originating from the left ventricular epicardium adjacent to the transitional area from the great cardiac vein to the anterior interventricular vein (DGCV-AIV), the most efficient catheter manipulation approach has not been fully elucidated. OBJECTIVE This study aimed to investigate a more appropriate catheter manipulation approach for DGCV-AIV VAs. METHODS One hundred twenty-three consecutive patients with DGCV-AIV VAs were retrospectively analyzed. All these patients were firstly mapped and ablated by conventional approach （Non-Swartz sheath support (NS) approach）. When target sites not been reached, Swartz sheath support (SS) approach was attempted. If target sites still unreached, the hydrophilic coated guide wire and left coronary angiographic catheter-guided deep engagement of Swartz sheath in GCV to support ablation catheter was performed. RESULTS A total of one hundred three VAs (103/123, 83.74%) were successfully eliminated in DGCV-AIV. By NS approach, the tip of catheter reached DGCV in 39.84% VAs (49/123), reached target sites in 35.87% VAs (44/123), and achieved successful ablation in 30.89% VAs (38/123), which was significantly lower than by SS approach (88.61% (70/79), 87.34 % (69/79), and 84.81% (67/79), P<0.05). In left anterior oblique (LAO) view, angle between DGCV and AIV<83° indicated an inaccessible AIV by catheter tip with a predictive value of 94.5%. Width/height of coronary venous system>0.69 more favored a SS approach with a predictive value of 87%. CONCLUSION For RFCA of VAs arising from DGCV-AIV, the SS approach facilitates the catheter tip achieve target sites and contributes to a successful ablation.