Objective To characterize the electroanatomical mapping and to assess the value of radiofrequency ablation of atrial tachycardia (AT) in left atria. Methods Nine patients with AT in left atria were studied. Three-dimensional electroanatomical maps were constructed in left atrium using electroanatomical mapping system (Carto). The type of AT (focal or macroreentrant) was identified by the electroanatomical maps, and the ablation targets were at the earliest activation sites or the isthmus of circuit. Results There were ten ATs in 9 cases. The relatively early A waves were recorded in middle, distal or proximal parts of coronary sinus catheter. Nine focal ATs were diagnosed. The activation maps demonstrated that the earliest activation sites were at the ostium of pulmonary veins ( n =5), posterior area of left atrium ( n =2), ostia of left atria appendage ( n =1) or left atria appendage ( n =1) respectively. One macroreeentrant AT was diagnosed, whose circuit propagated through the isthmus, formed by the right superior pulmonary vein and fossa ovalis. Eight focal ATs were all ablated successfully at the earliest activation sites, and one AT from left atria appendage was ablated unsuccessfully. Line of ablation was performed at the isthmus of the macroreentrant AT. During a period of 6-30 months follow-up, one patient with focal AT recurred and underwent another ablation with successful result. No complication occurred. The procedure time and the fluoroscopic time were 90-140 min, 8-16 min respectively in successful cases. Conclusion These results suggest that electroanatomical mapping of AT in left atria may facilitate rapid and accurate identification of the type of AT and guide ablation safely or effectively with less fluoroscopic time and higher success rate, especially in unsuccessful cases with conventional technique.

Objective To investigate the level and the source of inflammatory factors in patients with paroxysmal atrial fibrillation.Methods Thirty patients with paroxysmal atrial fibrillation were selected as observation group,and 20 cases of patients with paroxysmal supraventricular tachycardia were selected as control group.The blood samples of coronary sinus,right atria,left atria and femoral vein were consecutively collected during the procedure of radiofrequency ablation.The level of tumor necrosis factor (TNF)-α,soluble tumor necrosis factor receptor-1 (sTNFR1),and interleukin(IL)-6 was detected by ELISA separately and compared between two groups.Results The level of TNF-α and IL-6 of coronary sinus,right atria,left atria and femoral vein in observation group was significantly higher than that in control group [TNF-α:(4.45 ± 1.76) ng/L vs.(0.59 ± 0.36) ng/L,(6.67 ± 1.43) ng/L vs.(0.51 ± 0.30) ng/L,(8.35 ± 2.03) ng/L vs.(0.85 ± 0.50) ng/L,(9.97 ± 2.70) ng/L vs.(0.28 ± 0.29) ng/L,P=0.000;IL-6:(2.02 ± 0.87) ng/L vs.(1.04 ± 0.63) ng/L,(1.51 ± 0.68) ng/L vs.(0.74 ± 0.26) ng/L,(2.00 ± 0.51) ng/L vs.(0.88 ± 0.35) ng/L,(1.32 ±0.47) ng/L vs.(0.48 ±0.28) ng/L,P =0.000].The level of high sensitivity C reactive protein (hs-CRP) in observation group was significantly higher than that in control group [(2.41 ± 1.35) mg/L vs.(1.10 ±0.53) mg/L,P =0.002].The level of TNF-αof left atrium in observation group was significantly higher than that of other three sites (P=0.000).The level of IL-6 in the coronary sinus and femoral vein was significantly increased,compared with that in the right atria and left atria (P ＜ 0.05).The level of sTNFR 1 in the femoral vein,right atria and coronary sinus difference was not statistically significant (P ＞ 0.05),but was significantly higher than that in the left atria(P ＜ 0.05).The level of TNF-α,IL-6 and hs-CRP was correlated with the diameter of left atrium (LAD) (P ＜ 0.01 or ＜ 0.05).The level of sTNFR1 in left atria was positively correlated with LAD,and the level of sTNFR1 in right atria was negatively correlated with LAD (P ＜ 0.01).Conclusions The level of TNF-α,IL-6 and hs-CRP is increased in patients with paroxysmal atrial fibrillation.TNF-α and IL-6 may come from the heart and is related with the enlargement of left atrium.

Objective To observe efifcacy and safety of catheter ablation for atrial ifbrillation (AF) occurring after surgical valve replacement in patients with rheumatic heart disease (RHD). Methods A total of 23 RHD patients with atrial ifbrillation after surgical valve replacement were enrolled in this study from 2008 to 2013. The clinical characteristics, ablation strategies and successful rate were investigated. Results All the cases included 8 males and 15 females (age, 51.0 ± 9.2 years). Valves replaced were isolated mitral valves (13/23, 56.5%) and multiple valves (10/23, 43.5%). Postoperative AF after cardiac surgery was paroxysmal in 14 patients (60.9%) and nonparoxysmal in 9 cases. Nine patients (39.1%) was in sinus rhythm before cardiac surgery, 4 in paroxysmal AF and 10 in non-paroxysmal AF. The mean interval between the catheter ablation AF and the surgical intervention was (6.9±5.8) years. The postoperative AF duration was (3.1±3.2) years, left and right atrial diameters were (44.1±5.9) mm and (48.1±9.0) mm respectively, left ventricular ejection fraction was 64.0%±8.3%, the mean ablation procedure duration was (156.8±46.6) min, and lfuoroscopy exposure averaged (27.3±11.2) min. Standard pulmonary vein isolation was performed in all cases by using ipsilateral circumferential ablation technique. Additional ablation, including complex fractionated atrial electrograms, mitral and tricuspid isthmus, and left atrial roof, was applied in most of the cases. After a mean follow-up of (29.7±21.2) months (median, 24 months), 60.9%of the patients remained free of AF, 1 died, and 2 lost to follow-up. Conclusions Catheter ablation for AF is effective and safe in patients with RHD after surgical valve replacement. Stepwise ablation strategy may be better for these patients.

Objective To analyze the clinical characteristics and follow-up data of catheter ablation of recurrent atrial tachycardias (ATs) after Mini-Maze surgery,and to explore prognostic factors for recurrence.Methods 59 patients in Guangdong General Hospital with ATs post Mini-Maze and concomitant open-heart surgery from April.2010 to June.2015 were included.According to high density precise mapping,activation mapping,voltage mapping and entrainment mapping,they underwent electrophysiological study and ablation which was guided by three-dimensional mapping system.All patients were followed up regularly.We explored the prognostic factors for recurrence by the Cox regression analysis.Results There were 88 types of ATs being mappedwith mean (1.49 ± 0.75) types of ATs identified per case.Most ATs were macro-reentry ATs(67/88,76.1％)and focal ATs (20/88,22.7％),respectively.56 patients (94.9％) achieved immediate ablation success.In a mean follow-up of (30.8 ± 17.7) months,recurrences were observed in 12 patients after the first time catheter ablation.Recurrent time was 3.5 (1.3,12.0) months and the overall ablation success rate was 74.6％ (44/59).6 patients received second ablation and the achievement of freedom from arrhythmias reached 79.7％ (47/59).Multivariate analysis showed that the LA diameter was the independent predictor for recurrence (HR 1.108,95％ CI 1.002 to 1.226,P =0.045).Conclusion Catheter ablation of ATs post Mini-Maze with concomitant surgery is save and feasible.LA diameter is the independent predictor for recurrence.

Objective:To develop a national secondary reference material of Urea and Creatinine in frozen human serum as a standard for metrological traceability.Methods:According to JJF1343-2012 "General and Statistical Principles for Characterization of Reference Materials" and JJF 1006-1994 " Technical Norm of Primary Reference Material ", the homogeneity, stability, and commutability were evaluated;Using the JCTLM recommended methods, the value of the reference materials was assigned through collaboration with 6 accredited reference laboratories from Guangdong Provincial Hospital of Chinese Medicine, Beijing Aerospace General Hospital, Shenzhen Mindray Bio-Medical Electronics, Maccura Biotechnology, Beijing Leadman Biochemistry, and Zhejiang MedicalSystem Biotechnology. Uncertainty components including inhomogeneity, stability and value assignment were evaluated.Results:The results of one-way analysis of variance of homogeneity for the reference materials showed P>0.05, and the stability evaluation was less than the critical value of the t-test. The measured values were in the 95% confidence interval in the four conventional detection systems for commutability, and the certified values and expanded uncertainties were urea:(14.7±0.3) mmol/L ( k=2),Cr:(313.9±14.5) μmol/L ( k=2). Conclusion:The prepared secondary reference materials of urea and creatinine had promising homogeneity, stability, and commutable, the values of urea and creatinine concentration in reference materials were accurate and reliable.

Objective    To evaluate the efficacy of hybrid ablation through compared with thoracoscopic epicardial ablation. Methods    In this study, 108 patients with all long-standing persistent atrial fibrillation (LSPAF) received thoracoscopic epicardial ablation (TEA) after enrollment. There were 82 males and 26 females at age of 56.5±9.4 years. After blanking-period, patients off antiarrhythmic therapy with sinus rhythm were divided into a hybrid ablation (HA) group (50 patients) and a TEA group (58 patients). Only patients in the HA group received catheter ablation after randomization subsequently. In at least two-year observation period, cardiovascular risk factors were observed in all groups’ patients. Results    The mean follow-up duration was 17.3-41.8 (26.9±6.1) months and there was no significant difference between two groups [8.2-40.6 (27.5±5.7) months in the HA group and 17.3-41.8 (26.4±6.7) months in the TEA group]. The off antiarrhythmic agents (AADs) sinus rhythm rate was significantly higher in the HA group than that in the TEA group at the time of postoperative 6, 12, 24 and 36 months ［96.0%, 90.0%, 83.7%, 83.7% versus 79.3%, 75.9%, 67.3%, 63.1%, HR=0.415 (95%CI 0.206-0.923)]. Conclusion    We can conclude that the efficacy of two-staged hybrid ablation for LSPAF is superior to thoracoscopic epicardial ablation alone. Patients can obtain benefit from a supplemental radiofrequency catheter ablation after blanking-period of surgical ablation, instead of those without a supplemental ablation.

Radiotherapy is widely used in the management of advanced colorectal cancer (CRC). However, the clinical efficacy is limited by the safe irradiated dose. Sensitizing tumor cells to radiotherapy via interrupting DNA repair is a promising approach to conquering the limitation. The BRCA1-BARD1 complex has been demonstrated to play a critical role in homologous recombination (HR) DSB repair, and its functions may be affected by HERC2 or BAP1. Accumulated evidence illustrates that the ubiquitination-deubiquitination balance is involved in these processes; however, the precise mechanism for the cross-talk among these proteins in HR repair following radiation hasn't been defined. Through activity-based profiling, we identified PT33 as an active entity for HR repair suppression. Subsequently, we revealed that BAP1 serves as a novel molecular target of PT33 via a CRISPR-based deubiquitinase screen. Mechanistically, pharmacological covalent inhibition of BAP1 with PT33 recruits HERC2 to compete with BARD1 for BRCA1 interaction, interrupting HR repair. Consequently, PT33 treatment can substantially enhance the sensitivity of CRC cells to radiotherapy in vitro and in vivo. Overall, these findings provide a mechanistic basis for PT33-induced HR suppression and may guide an effective strategy to improve therapeutic gain.