Objective: To explore the application value of ablation catheter for pacemaker atrial lead restoration in relevant patients.
Methods: A total of 6 patients with atrial lead dislodgement after pacemaker implantation were selected for our study. The atrial lead restoration was conducted by using ablation catheter via femoral vein pathway.
Results: The average operational time was (15.0 ± 3.7) min which was obviously less than traditional operational time. The position of electrode restoration was ideal with well immobilization.
Conclusion: Ablation catheter is feasible for arial lead restoration in patients with atrial lead dislodgement after pacemaker implantation.

Objective:To establish and validate an LC-MS/MS method for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in cerebrospinal fluid. Additionally, the consistency between this method and three mainstream detection methods was evaluated.Methods:This study involved method establishment, validation, and consistency evaluation. The N15 labeled β-amyloid protein was used as the internal standard. Extraction was performed using Waters MCX 96-wells solid phase extraction plate, and the eluent was collected to QuanRecovery MaxPeak 700 μl plate. At the positive ion mode, the multi-reaction ion monitoring mode based on electric spray ionization is chosen for the determination of CSF Aβ 1-42, Aβ 1-40, and Aβ 1-38. Referring to the CLSI C62-A and EP-15A3 guidelines, the method is evaluated and verified, including quantitation of limit (LOQ), linearity, recovery, precision, and accuracy. In addition, a total of 57 clinical residual CSF samples were collected and the concentrations of Aβ 1-42 and Aβ 1-40 were determined based on manual INNOTEST ELISA assay and Lumipulse G and Roche Elecsys fully automated biochemical analyzers. The comparison analysis and deviation evaluation were conducted by passing-bablok and Bland Altman methods.Results:The analysis time of this method is 8 min, and the LOQ of Aβ 1-42, Aβ1-40 and Aβ1-38 is 0.1 ng/ml, 0.5 ng/ml, and 0.1 ng/ml, respectively, and the linear range can meet the needs of clinical detection. Respectively, the recovery is 86.2%-93.8%, 100.9%-103.9% and 103.3%-107.1%; the total imprecision is 4.7%-7.4%, 3.5%-4.6% and 5.2%-10.9%. The measured values of Aβ 1-42 certified reference materials are all within the allowable uncertainty requirements. Moreover, the carryover rate of three analytes was all≤0.11%. In addition, the correlations of Aβ 1-42 and Aβ1-40 in CSF between this LC-MS/MS method and the INNOTEST ELISA method, Lumipulse G and Roche Elecsys fully automated biochemical analyzers were all deemed good, with correlation coefficient (r) ranging from 0.920 to 0.970. However, the measured values between the four methods were remarkably different.Conclusion:We established and validated a robust method based on LC-MS/MS technology for simultaneous determination of Aβ 1-42, Aβ 1-40, and Aβ 1-38 in CSF. The method is accurate, simple, and suitable for clinical measurements. However, despite good correlations, there were substantial differences in the measurement results of Aβ 1-42 and Aβ 1-40 among different analytical platforms, indicating the need for further promotion of harmonization and standardization processes for AD classic biomarkers.

Objective To evaluate the analytical performance of four lipoprotein associated phospholipase A2(Lp-PLA2)activity reagents on Beckman AU5800 automatic biochemical analyzer. Methods The remaining serum samples of 214 patients and 140 apparently healthy individuals were collected from March to July 2017 in Peking Union Medical College Hospital.These samples were used for method comparison and reference interval evaluation.According to the guidelines of EP15-A,EP6-A,EP-17 and EP7-P from Clinical and Laboratory Standards Institute(CLSI)standards,the precision, linearity, sensitivity and common interferences(e.g free bilirubin, conjunct bilirubin, hemoglobin and chyle)were assessed.According to EP9-A2,method comparisons of differents regents(Evermed,DiaSys,Hengxiao and Zhongyuan were labeled as A,B,C and D,respectively)were conducted and the differences were estimated at medical decision levels(328U/L,391U/L and 485U/L).Results The precision of four reagents were acceptable.The repeatability(CV%)of A to D were 0.5%-1.7%, 0.7%-3.0%, 0.9%-2.0% and 0.5%-3.3%,respectively.The reproducibility(CV%)were 0.7%-2.9%, 1.4%-3.2%, 1.3%-1.9%and 0.8%-4.1%,respectively.Both of those achievedlaboratory defined quality objective(<5%).The linearity of A to D were 44 -1 992 U/L,39 -1 798 U/L,13 -540 U/L and 75-1 717U/L,respectively.The regression coefficient R2 was between 0.997 and 1.000, and the correlation coefficient(r)was between 0.998 and 1.000.The interference of chyle were acceptable among these four reagents andmet the manufacturer′s requirementsor clinical needs.In a low level of Lp-PLA2,bilirubin had an obvious interferenceonreagent C;B and C were negatively affected when the hemoglobin was 4.5 g/L; and D was positively affected when the hemoglobin was 2.45 g/L.The regression coefficients R2 of A,C,D compared with B were between 0.978 and 0.995,and the correlation coefficients(r)were between 0.989 and 0.998. The expected differences at medical decision levels ranged from -240 U/L to 113 U/L.For A to D,the Lp-PLA2 activity results of 131(93.6%), 140(100%), 82(58.6%), and 128(91.4%)cases were analysed within the manufacturer′s claimed reference intervals.Conclusion The precision and linearity of the four Lp-PLA2 activity detection reagents used in automatic biochemical analyzer are good, but the anti-interference ability needs to be improved.

Objective: To compare the consistency of thyroid stimulating hormone (TSH) results from four chemiluminescence assays. Methods: A total of 102 fresh serum samples from Peking Union Medical College Hospital during March 2018 and April 2018 were collected for precision evaluation and methodological comparison referring to CLSI EP15-A2 and EP9-A2 protocols. The levels of serum TSH were detected by Abbott i2000 (system A), Beckman DXI800 (system B), Siemens ADVIA Centaur XP (system C) and Roche e601 (system D) automatic chemiluminescence analyzers and their matching reagents, respectively. The obtained results were compared with the passing-bablok and Bland Altman methods. Taking 0.27 μIU/mL and 5.33 μIU/mL as the medical decision level, the expected bias of each detection system was compared. Results: The precisions of systems A,B,C and D were 1.7%-3.3%， 2.3%- 3.9%，0.7%-2.3% and 0.6%-1.5%,respectively. The median (P 25,P 75) of TSH concentrations detected by systems A,B,C and D were 1.898 (0.518,4.809)μIU/mL, 2.819 (0.719,7.020)μIU/mL,2.502 (0.692,6.888)μIU/mL and 3.105 (0.886, 7.905)μIU/mL, respectively. The coefficients of determination (R 2 ) of regression equation were above 0.975 for 4 detection systems. The correlation coefficients (r), intercepts and slopes of 4 detection systems were 0.993 5-0.997 1, 0-0.06 and 0.59-1.15, respectively, and systems B and C had the best correlations with 1.02 of slope and 0 of intercept. The deviation plot showed that the bias% of 4 detection systems was between -48.1% and 17.3%. Among them, systems A and D had the largest bias, while systems B and C had the lowest bias. The expected bias of 4 detection systems at the medical decision level was -40.7%-37.2%. Conclusion The consistency between Beckman and Siemens TSH detection systems is good, while those of Roche and Abbott TSH detection systems are different from the other two.