ABSTRACT
Variant pulmonary vein anatomy (PVA) has been reported to influence the recurrence of atrial fibrillation (AF) after radiofrequency ablation.However,the effects of PVA on AF in patients undergoing cryoballoon ablation (CBA) remain unknown.The present study aimed to examine the impact of PVA on the long-term outcome of CBA for AF.A total of 78 patients (mean age 60.7±10.9 years,64.1％ males) with symptomatic and drug-refractory paroxysmal AF were enrolled in the study.Left atrium (LA) and PVA acquired at computed tomography angiography (CTA) were reconstructed with CARTO(R) 3 SYSTEM.Patients were routinely evaluated by 24-hour Holter monitoring following CBA.Cox regression was used to detect the predictors of AF recurrence after CBA.The results showed abnormal PVA in 30 patients (38.5％) and 18 patients (23.1％) had left common PV (LCPV).Electrical pulmonary vein isolation was achieved in all patients.After a mean follow-up of 689.5±103.8 days,it was found that patients with abnormal PVA had similar AF recurrence rate to those with normal PVA (26.7％ vs.25.0％,P=0.54),and there was no significant difference in AF recurrence rate between LCPV patients and non-LCPV patients (33.7％ vs.23.3％,P=0.29).Cox regression analysis showed that AF duration (72.9±9.0 vs.42.3±43.2 months,HR 1.001;95％CI 1.003-1.014;P＜0.001) and cryo-applications of right-side PVs (3.0±1.6 vs.4.7±1.7,HR 0.661;95％ CI 0.473-0.925;P=0.016) were independent predictors of freedom from AF,but PVA was not identified as a predictor of long-term success.In conclusion,the variant PVA cannot significantly influence the long-term outcome of AF patients undergoing CBA;longer AF duration and less cryo-applications of right-side PVs are associated with higher AF recurrent rate.
ABSTRACT
Variant pulmonary vein anatomy (PVA) has been reported to influence the recurrence of atrial fibrillation (AF) after radiofrequency ablation.However,the effects of PVA on AF in patients undergoing cryoballoon ablation (CBA) remain unknown.The present study aimed to examine the impact of PVA on the long-term outcome of CBA for AF.A total of 78 patients (mean age 60.7±10.9 years,64.1％ males) with symptomatic and drug-refractory paroxysmal AF were enrolled in the study.Left atrium (LA) and PVA acquired at computed tomography angiography (CTA) were reconstructed with CARTO(R) 3 SYSTEM.Patients were routinely evaluated by 24-hour Holter monitoring following CBA.Cox regression was used to detect the predictors of AF recurrence after CBA.The results showed abnormal PVA in 30 patients (38.5％) and 18 patients (23.1％) had left common PV (LCPV).Electrical pulmonary vein isolation was achieved in all patients.After a mean follow-up of 689.5±103.8 days,it was found that patients with abnormal PVA had similar AF recurrence rate to those with normal PVA (26.7％ vs.25.0％,P=0.54),and there was no significant difference in AF recurrence rate between LCPV patients and non-LCPV patients (33.7％ vs.23.3％,P=0.29).Cox regression analysis showed that AF duration (72.9±9.0 vs.42.3±43.2 months,HR 1.001;95％CI 1.003-1.014;P＜0.001) and cryo-applications of right-side PVs (3.0±1.6 vs.4.7±1.7,HR 0.661;95％ CI 0.473-0.925;P=0.016) were independent predictors of freedom from AF,but PVA was not identified as a predictor of long-term success.In conclusion,the variant PVA cannot significantly influence the long-term outcome of AF patients undergoing CBA;longer AF duration and less cryo-applications of right-side PVs are associated with higher AF recurrent rate.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the thickness and viscoelasticity of whole saliva (WS), parotid saliva (PS) and submandibular/sublingual gland saliva (SMSLS) film adsorption on the hydroxyapatite (HA) surface.</p><p><b>METHODS</b>Ultra-thin layer of HA nanocrystals was coated on the dissipation TiO(2) sensor of gold quartz crystal microbalance using electrophoretic deposition technique. The thickness of the HA layer was measured by the ellipsometer, and element analysis was conducted using X-ray photoelectron spectroscopy. Atomic force microscopy and scanning electron microscope were used to observe its morphology. The in-situ adsorption thickness, the shear elastic modulus and the shear viscosity of salivary layers (WS, PS and SMSLS) on HA surfaces were investigated. The statistical data were analysed by an one-way ANOVA analysis followed by a SNK-q test.</p><p><b>RESULTS</b>The results show that the HA layer was a plate-like morphology with 1.53 ± 0.12 in Ca/P molar ratio, (19.1 ± 0.9) nm in the thickness and (6.5 ± 1.6) nm in the roughness. The thickness of salivary film was SMSLS [(21.84 ± 1.25) nm] > WS[(17.91 ± 1.35) nm] > PS [(14.30 ± 1.03 nm) (P < 0.05). The shear elastic modulus of salivary film was PS [(0.61 ± 0.01) MPa] > SMSLS [(0.31 ± 0.09) MPa] and WS [(0.25 ± 0.03) MPa] (P < 0.05). The trend of the shear viscosity was opposite to one of thickness.</p><p><b>CONCLUSIONS</b>The characteristics of saliva adsorption on HA surface suggest that the thicker, softer and more hydrated properties for the SMSLS and WS films are likely to afford a stronger lubrication to protect oral surfaces from wear and dehydration. The viscoelasticity of the PS film is probably related to the retention covering the oral cavity.</p>
Subject(s)
Adult , Female , Humans , Male , Young Adult , Adsorption , Durapatite , Chemistry , Microscopy, Atomic Force , Parotid Gland , Bodily Secretions , Photoelectron Spectroscopy , Quartz Crystal Microbalance Techniques , Saliva , Chemistry , Sublingual Gland , Bodily Secretions , Submandibular Gland , Bodily Secretions , Surface Properties , ViscosityABSTRACT
<p><b>BACKGROUND</b>Ibutilide has been commonly used for pharmacologic cardioversion of atrial fibrillation and flutter in clinical settings. The objective of this study was to investigate the effects of ibutilide on the defibrillation threshold (DFT), restitution properties, dispersion of refractoriness and activation patterns during ventricular fibrillation (VF).</p><p><b>METHODS</b>Ibutilide was administrated intravenously in six open-chest beagles. Before and after the drug administration, 20-second episodes of VF were electrically induced and recorded with a 10×10 unipolar electrode plaque sutured on the lateral epicardium of the left ventricle. DFT and VF activation patterns, including type of epicardial activation maps, VF cycle length (VF-CL), conduction velocity, wavelength (WL) and reentry incidence, were measured. Restitution properties and dispersion of refractoriness were estimated from activation recovery intervals (ARI) during pacing.</p><p><b>RESULTS</b>Compared to baseline, ibutilide markedly decreased the DFT by 31% ((491 ± 14) V vs. (337 ± 59) V, P < 0.01). The drug significantly reduced the maximal slope of the restitution curve (1.34 ± 0.08 vs. 0.76 ± 0.06, P < 0.01) and its epicardial dispersion (0.36 ± 0.09 vs. 0.21 ± 0.06, coefficient of variation, P = 0.03). The dispersion of refractoriness was enhanced at the pacing cycle length of 300 ms to 160 ms by ibutilide. The drug significantly increased the VF-CL ((96 ± 19) ms vs. (112 ± 20) ms, P < 0.01) and the WL ((41 ± 9) mm vs. (52 ± 14) mm, P = 0.02) during VF, and reduced the reentry incidence by 25% (0.08 ± 0.02 vs. 0.06 ± 0.02, P < 0.01). In the epicardial activation maps, ibutilide significantly reduced the percentage of more complex activation maps during VF.</p><p><b>CONCLUSIONS</b>Intravenous ibutilide significantly decreased the DFT. It might be due to reduction of activation pattern complexity during VF.</p>
Subject(s)
Animals , Dogs , Anti-Arrhythmia Agents , Therapeutic Uses , Pericardium , Sulfonamides , Therapeutic Uses , Ventricular Fibrillation , Drug TherapyABSTRACT
<p><b>OBJECTIVE</b>To measure the translucency parameter (TP), masking effect (ME), and contrast ratio (CR) of opal porcelain of Ceramco, Shofu, Noritake, and Vita, and to compare the correlations among the three transmission parameters, in order to provide reference for selecting opal porcelain correctly.</p><p><b>METHODS</b>The color of specimens was measured according to CIE L*a*b* under different background and reflectance mode with a Color-Eye 7000A spectrophotometer. The color difference, TP, and ME value were calculated. Within 400-750 nm spectra, the ratio of light reflectance was measured, and CR was also calculated. The data was compared by ANOVA and SNK-q test (alpha=0.05). The correlation and multiple linear regression between TP, CR, and ME were analyzed (alpha=0.05).</p><p><b>RESULTS</b>There were statistical difference with different shade of the same brands (P<0.05). The correlations between ME and TP, TP and CR, ME and CR were existed (P<0.05). TP was correlated not only with ME but also with CR based on multiple regression analysis (P<0.05). The partial correlation coefficients were statistically significant (P<0.05). CR was the main devotion to translucency parameter on multiple regressions.</p><p><b>CONCLUSION</b>It is recommended to select opal porcelains based on transmission parameters. CR value has an inner significance of opaque property of opal porcelain and can express opacity property of opal porcelain more appropriately than ME.</p>
Subject(s)
Humans , Color , Dental Porcelain , SpectrophotometryABSTRACT
<p><b>OBJECTIVE</b>The aim of this investigation was to examine the changes of the color stability, surface microstructure and chemical constitution of light-curing composite resin after accelerated aging, and the relations between them.</p><p><b>METHODS</b>Four light-curing composite resin were aged in an accelerated aging instrument. The color was measured by CIE L*a*b* with a spectrophotometer after treatment for 24 h and 96 h. And the color differences were calculated. Environmental scanning electron microscopy (ESEM) and Fourier transform infrared spectroscopy (FTIR) spectrometer were used to examine the microstructure and chemical composition of the specimens before and after accelerated aging. The color differences were analyzed statistically by repeated-measures two-way analysis of variance and t-test after aging for 24 h and 96 h. The level of significance was defined as alpha=0.05.</p><p><b>RESULTS</b>The materials demonstrated statistically significant differences in color after aging between the 24 h and 96 h (P<0.05). There were significant influences on the microstructure and the chemical composition after aging. The matrix appeared some concaves and pores, the filler particles exposed after aging. The energy of chemical bonds were weaken or broken under the aging, and the unsaturated polymer reacted again.</p><p><b>CONCLUSION</b>The color differences of the composite resin increase with the aging time and irradiation dose. The hybrid filled composites have the best color stability.</p>