ABSTRACT
Objective@#To evaluate the efficacy and safety of nifekalan (NIF) on cardioversion in atrial fibrillation (AF) patients post radiofrequency ablation, and investigate the relevant factors related to the cardioversion efficacy of NIF.@*Methods@#We screened patients with sustained AF rhythm after radiofrequency ablation between November 2016 and July 2018. Participants were treated with intravenous NIF 0.4 mg/kg within 5-10 minutes after ablation. We observed the adverse reaction, and monitored the rhythm, heart rate, QT interval and QTc interval before the medication and at 5, 10, 20, 120 min after the medication. According to the drug outcome of NIF, patients were divided into conversion group and non-conversion group, related factors affecting conversion efficacy were evaluated using logistic regression analysis.@*Results@#(1)A total of 116 patients were enrolled in the study (63 males and 53 females, mean age was (64±18) years). Among them, 72 patients were converted to sinus rhythm, and the overall successful rate was 62.1%. There were 84 patients with persistent AF, of which 50 cases (59.2%) were restored to sinus rhythm. There were 32 patients with paroxysmal AF, 22 cases (68.8%) of them were restored to sinus rhythm. The conversion time was 1.5 to 12 (6.8±3.4)min. (2) In 116 patients, the QT interval and QTc interval were significantly longer after medication than before the drug administration (P<0.01), and peaked at about 10th min, and restored to the level before drug administration at about 120th min. (3) There were 8 cases of bradycardia (6.9%), 3 cases of frequent and short ventricular tachycardia (2.6%). (4) The duration of atrial fibrillation was shorter and left atrial diameter was smaller in the cardioversion group than in the non-cardioversion group (both P<0.05). There were no significant differences in gender, disease history, atrial fibrillation type and structural heart disease between the two groups (P>0.05). (5) Multifactorial logistic regression analysis showed that the duration of atrial fibrillation (OR=0.980, 95%CI 0.966-0.994, P=0.004) and the left atrial diameter (OR=0.888, 95%CI 0.814-0.967, P=0.007) were the factors that influence the cardioversion efficacy of NIF on atrial fibrillation post ablation.@*Conclusions@#The total effective rate of NIF was 62.1% in patients witrh sustained AF post radiofrequency ablation, was 68.8% in patients with paroxysmal AF. Besides, NIF has the advantage of short conversion time and few adverse reactions. Left atrium diameter and AF duration were relevant factors that influence the efficacy of NIF of cardioversion in patients with sustained AF after radiofrequency ablation.
ABSTRACT
AIM: To observe the change of subunit of NADPH oxidation enzyme complex nox - 1 protein in cardiocyte hypoxia - reoxygenation injury and the role of cardiotrophin -1.METHODS: Cardiomyocytes from the hearts of 1 -3 d old neonatal rats were prepared by a modified method. Five groups were included in the study: control; hypoxia/ reoxygenation; hypoxia/reoxygenation + CT - 1; CT - 1 + hypoxia/reoxygenation + LY294002 (PIK3/Akt inhibitor) ; CT -1 + hypoxia/reoxygenation + PD98059 (ERK inhibitor) ; CT - 1 + hypoxia/reoxygenation + DMSO. The concentration of CT -1 was 10 μg/L. The survival rate of myocytes was evaluated by MTS method. Apoptosis, mitochondrial permeability transition pore ( △ψm) and reactive oxygen species ( ROS) were detected by flow cytometry. Nox - 1 protein was determined by Western blotting. RESULTS: Apoptosis of cardiomyocytes and the level of ROS (19.7% ±1.4% vs 2.1% ± 0.5% , 14.07% ± 1.25% vs 3.54% ± 0.86% , P < 0.05 ) increased markedly after hypoxia/reoxygenation, but cardio-myocyte survival rate and the level of△ψm (40.55% ±4.25% vs 86.28% ±7.15% , P <0.01) decreased significantly. The expression of nox - 1 protein was upregulated markedly. With CT - 1 intervention, cardiomyocyte survival rate increased markedly, apoptosis, both ROS and expression of nox - 1 protein reduced significantly. The level of△ψm increased obviously. The effect of CT - 1 was inhibited by LY294002.No significant effect was observed on cells survival in DMSO group, which confirmed that LY294002 was specifically involved in blocking the protective effect of CT - 1.CONCLUSION : The expression of subunit of NADPH oxidation enzyme complex nox - 1 protein is upregulated markedly in cardiocyte hypoxia - reoxygenation injury.CT - 1 protects cardiac cells against hypoxia - reoxygenation injury by downregulating the expression of nox -1 protein to decrease the level of ROS.
ABSTRACT
Objective To study the effect of Cardiotrophin-1 (CT-1) on cardiocyte hypoxia-reoxygenation injury,and to investigate the signaling pathways involved in the protective effect. Method This study was carried out in Key Lab of Molecular Medicine in Jiangxi Province. Cardiomyocytes from the hearts of 2-day-old Sprague-Dawley neonatal rats were prepared by a modified method. Five groups were included in the study. Group (ⅰ): control, Group (ⅱ): hypoxia/reoxygeuation, Group (ⅲ): hypoxia / reoxygenation + CT-1, Group (iv) : CT- 1 + hypoxia/ reoxygenation + LY294002 (PIK3/Akt inhibitor), Group (ⅴ): CT-1 + hypoxia / reoxygenation +DMSO. The concentration of CT-1 was 10 ng/mL. Myocytes survival rote was evaluated by MTS method, apopto-sis, mitochondrial permeability transition pore (△ψm) and reactive oxygen species(ROS) were detected by flow cy-tometer, phosphorylased GSK-3β and PI3K protein by western blotting. Analysis of variance and q test as statistical methods was used to analyze the data. Results Cardiomyocyte apoptosis and ROS increased markedly after hy-poxia/reoxygenation,but cardiomyocyte survival rate and the level of △ψm [(40.55±4.25) vs. (86.28±7.15), P < 0.01]decreased significantly. With CT-1 intervention, cardiomyocyte survival rate increased markedly (87%),apoptosis and ROS reduced significantly. The level of △ψm increased, the level of phosphorylased GSK-3β and phosphorylased PI3K protein obviously increased. The effect of CT-1 was inhibited by LY294002, but no significant effect was observed on ceils survival in DMSO group, which confirmed that LY294002 specifically in-volved blocking the protective effect of CT-1. Conclusions CT-1 can protect cardiac cells against hypoxia- reoxy-genation injury, these effects are dependent upon its ability to activate the PI3K/GSK-3β pathway.