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Chang C.-J.,Tungs Taichung Metroharbour Hospital | Lin Y.-J.,Taipei Veterans General Hospital | Lin Y.-J.,National Yang Ming University | Higa S.,University of Ryukyus | And 14 more authors.
Journal of Cardiovascular Electrophysiology | Year: 2010

Unipolar Electrogram Voltage in Patients with Atrial Fibrillation. Introduction: The peak electrogram voltage is a typical metric applied at each site for voltage mapping. However, the peak amplitude depends on the direction and complexity of the wavefront propagation. The root-mean-square (RMS) measure of the amplitude is a temporal integral that represents the steady-state value. The objective of this study was to investigate the disparities between the electrogram voltage during SR and AF by using 2 recording modalities: the conventional peak voltage and an RMS measurement. Methods and Results: This study enrolled 20 patients (age = 59 ± 13) with paroxysmal AF undergoing catheter ablation guided by Ensite array. The unipolar electrogram voltage during SR and AF (7 seconds in duration) was obtained from the same sites, and labeled by the 3-dimensional (3D) geometry. Overall 1,200 electrograms were analyzed from equally distributed mapping sites in the left atrium. A point-by-point comparison of the unipolar peak negative voltage (PNV) showed less agreement (Bland and Altman test: 10.4% outside 2 standard deviations, and intraclass correlation coefficient ICC = 0.64). The RMS voltage demonstrated agreement between SR and AF for all sites (BA test: 5.9% of the sites, and the ICC = 0.81). The probability of predicting a low-voltage during AF using the voltage during SR was significantly lower when using the PNV measurement compared to that when using the RMS voltage (15% vs 61%, P < 0.05). Conclusion: The peak electrogram unipolar voltage during AF did not represent the voltage during SR. The RMS amplitude may be an alternative metric for voltage mapping to characterize the myocardial substrate. (J Cardiovasc Electrophysiol, Vol. 21, pp. 393-398, April 2010) © 2009 Wiley Periodicals, Inc. Source


Lin Y.-J.,Taipei Veterans General Hospital | Lin Y.-J.,National Yang Ming University | Tsao H.-M.,National Yang Ming University | Chang S.-L.,Taipei Veterans General Hospital | And 14 more authors.
Heart Rhythm | Year: 2010

Background: The adjunctive role of dominant frequency (DF) mapping during complex fractionated electrogram (CFE) ablation of atrial fibrillation (AF) has not been clarified. Objective: The purpose of this study was to investigate whether DF distribution or substrate properties are related to fibrillatory activity in the left atrium (LA) and to evaluate the effect of CFE ablation on the different patterns of DF distribution. Methods: The study enrolled 50 nonparoxysmal AF patients who underwent mapping, pulmonary vein isolation, and CFE ablation. High-density DF and CFE mapping were performed from the center of DFmax centrifugally to the rest of the LA. The LA substrate was classified into two types depending on the presence of intra-LA DF gradients as type 1 (>20% of the average DF) or type 2 (<20% of the average DF). Results: In type 1, maximal CFE and DF gradients were observed at the boundary (n = 14) or center (n = 16) of the DFmax region. In type 2 (n = 20), less intra-LA DF gradient was observed (4.27 ± 1.92 Hz vs 1.14 ± 0.52 Hz for types 1 and 2, P <.001) and a large proportion of continuous CFEs extended from the center of DFmax (19% ± 11% and 42% ± 15% of the LA for types 1 and type 2, P = .001). The procedure termination rate and long-term sinus rhythm maintenance rate were lower in patients with a smaller DF gradient (P <.05). Conclusion: The spatial distribution of fractionated activity was associated with particular DF patterns in nonparoxysmal AF patients. Patients with an evident intra-LA DF gradient responded better to pulmonary vein isolation and continuous CFE ablation. © 2010 Heart Rhythm Society. Source


Huang C.-H.,National Chung Hsing University | Lai G.-H.,National Chung Hsing University | Lee M.-S.,Tungs Taichung Metroharbour Hospital | Lee M.-S.,China Medical University at Taichung | And 8 more authors.
Journal of Applied Microbiology | Year: 2010

Aim: Chicken anaemia virus (CAV) causes an economically important viral disease in chickens worldwide. The main aim of this study was to establish a rapid, sensitive and specific loop-mediated isothermal amplification (LAMP) assay for detecting CAV infection. Methods and Results: A set of four specific LAMP primers were designed based on the nucleotide sequence of the CAV VP2 gene, which encodes a nonstructural protein. These were used for the amplification of a specific target region of the VP2 gene. LAMP amplicons were successfully amplified and detected by DNA electrophoresis and by direct naked eye SYBR Green I visualization. A sensitivity test systematically demonstrated that the LAMP assay was superior to a conventional PCR assay with a minimum concentration limit of 100 fg compared to 10 ng for the conventional PCR. The specificity of the LAMP assay for CAV detection is consistent with conventional PCR. Using this established LAMP assay, infected and uninfected clinical samples obtained from an experimental farm were fully verified. Conclusions: A novel nucleic acid-based approach of LAMP assay was successfully developed for detecting CAV infection. Significance and Impact of the Study: In this study, these results indicate that the developed LAMP assay herein for CAV detection is a time-effective, simple, sensitive and specific test that can be used as an alternative approach in the future for large-scaled diagnosis on the farm of CAV infection. © 2009 The Society for Applied Microbiology. Source


Lim P.S.,Tungs Taichung Metroharbour Hospital | Lim P.S.,Providence University | Jeng Y.,Tungs Taichung Metroharbour Hospital | Wu M.Y.,Tungs Taichung Metroharbour Hospital | And 7 more authors.
PLoS ONE | Year: 2013

Background:Substantial evidence suggests that increased oxidative stress in hemodialysis (HD) patients may contribute to cardiovascular complications. Oxidative modifications of human serum albumin (HSA), the largest thiol pool in plasma, alter its biological properties and may affect its antioxidant potential in HD patients.Methods:We conducted a long-term follow-up study in a cohort of normoalbuminemic HD patients to examine the impact of redox state of serum albumin on patients' survival by measuring the human nonmercaptoalbumin (HNA) fraction of HSA.Results:After adjusting for potential demographic, anthropometric, and clinical confounders, a positive association of HNA level with the risk of death from cardiovascular disease (CVD) and all-cause mortality was observed in normoalbuminemic HD patients. Using stratified analysis, we found a stronger association between HNA level and the risk of death from CVD and all-cause mortality in patients with pre-existing CVD.Conclusions:Serum HNA level is a positive predictor of mortality in normoalbuminemic HD patients, especially among those with pre-existing CVD. Increased oxidative stress resulting from biological changes in serum albumin levels could contribute to accelerated atherosclerosis and the development of cardiovascular disease in HD patients. © 2013 Lim et al. Source


Lim P.S.,Tungs Taichung Metroharbour Hospital | Lim P.S.,Taipei Medical University | Chen H.-P.,Tungs Taichung Metroharbour Hospital | Chen C.-H.,Tungs Taichung Metroharbour Hospital | And 3 more authors.
Blood Purification | Year: 2015

Background: Albumin, the most abundant protein in the extracellular fluid, displays an important antioxidant activity. Increased levels of oxidized albumin levels (high human non-mercaptoalbumin (HNA) level) have been reported in the serum of patients with end-stage renal disease. In this study, we attempted to identify the albumin redox status in the serum of patients on peritoneal dialysis (PD) and examined the relationship between these proteins and the transport type of the peritoneal membrane and other clinical and laboratory variables. Methods: We performed a cross-sectional study of a cohort of 80 patients with end-stage renal disease receiving PD. Peritoneal transport characteristics were identified and after peritoneal equilibration test patients were grouped as high (high(H)/high-average (HA) group, n = 31) or low (low (L)/low-average (LA) group, n = 49) transporters. The redox state of human serum albumin was measured using high-performance liquid chromatography. Results: The fraction of human mercaptoalbumin (HMA) showed significantly higher values in patients with high transport status than those with low transport status (f(HMA) 64.0 ± 5.4 and 52.7 ± 10.4%, respectively). Our data showed that the H/HA transport characteristic was associated with lower albumin (3.76 ± 0.48 vs. 4.00 ± 0.35, p < 0.05), and lower levels of advanced oxidized protein product (p = 0.008) when compared with the L/LA type. A correlation analysis showed that there was a positive correlation between dialysate/plasma (D/P) creatinine and f(HMA) levels (r = 0.511, p < 0.0001), as well as hemoglobin levels r = 0.231, p = 0.044 and a negative correlation between D/P creatinine and serum albumin, cholesterol and LDL levels (r = -0.236, p = 0.039; r = -0.237, p = 0.038; r = -0.272, p = 0.018, respectively). Conclusions: This study showed that higher serum levels of reduced albumin f(HMA) appear to be associated with high/high average peritoneal membrane transport characteristics in the incident PD patients. © 2015 S. Karger AG, Basel. Source

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