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Objective@#To analyze the clinical characteristics of patients with idiopathic right ventricular outflow tract (RVOT) ventricular arrhythmias (VA) and factors related to the immediate success rate of radiofrequency ablation.@*Methods@#Patients diagnosed as idiopathic RVOT arrhythmia in Fuwai Hospital from February 2009 to January 2013 were retrospectively screened. Patients with structural heart disease or inherited arrhythmia were excluded. All patients underwent endocardial electrophysiological study and radiofrequency catheter ablation. Baseline clinical and operation records were collected and analyzed. Immediate success rate was defined as no inducible ventricular arrhythmia by isoprinosine and electrophysiological induction at the end of ablation. The origins of idiopathic RVOT were classified as septal, anterior, posterior, free wall site, epicardial and RVOT-aorta root site.@*Results@#A total of 468 patients were finally included, and the age was (40.4±13.3) years old and 60.5%(283/468) patients were female. Immediate radiofrequency success rate was 89.3%(418/468). Patients were divided into ablation success group (n=418) and ablation failure group (n=50). Percent of female patients and patients with interventricular septal origin was significantly higher in the ablation success group than in ablation failure group (261(62.4%) vs. 22 (44.0%) , P=0.01, and 233(55.7%) vs. 18(36.0%), P=0.005), while percent of patients with epicardial origin was significantly lower in the ablation success group than in ablation failure group (17(4.1%) vs. 11(22.0%), P<0.001). Immediate success rate was the highest for patients with the septal origin and the lowest for patients with epicardial origin (92.8%(233/251) vs. 60.7%(17/28), P<0.05). Multivariate analysis showed that the origin site of VAs was the most important independent factor related to the success rate of ablation. Compared with the septal origin patients, patients with RVOT-aorta root and epicardial origin VAs faced with 1.82-fold and 8.26-fold increased risk of failed ablation, respectively (OR=2.82, 95%CI 1.05-7.57, and OR=9.26, 95%CI 3.60-23.86). Sex category was not the independent risk factor for failed ablation(OR=1.76, 95%CI 0.93-3.33, P=0.08) .@*Conclusions@#The immediate success rate of radiofrequency catheter ablation for idiopathic RVOT ventricular arrhythmia is relative high, however, immediate success rate of radiofrequency catheter ablation is relatively low for patients with epicardial and RVOT-aorta root origin arrhythmia and VAs origin is an independent risk factor of immediate ablation success rate.
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Objective:To investigate the effect of hypoxia on the expression of forkhead box P3 (FOXP3) in human oral squamous cell carcinoma (OSCC) cells,and to clarify its possible epigenetic mechanism.Methods:Two kinds of OSCC cell lines,FaDu and OECM-1,were cultured under normoxic or hypoxic conditions for 18 h.The relative expression levels of FOXP3 mRNA and protein in the cells were detected by Real-time RT-PCR and Western blotting method.The histone modification levels on the FOXP3 gene promoter,including acetylation of histone 3 lysine 4 (H3K4ac),trimethylation of histone 3 lysine 4 (H3K4me3) and lysine 27 (H3K27me3),were analyzed by Chromatin Immunocipitation (ChIP) and quantitative PCR (ChIP-qPCR).The relative expression levels of histone deacetylase 3 (HDAC3) mRNA and inhibitory rates of FOXP3 mRNA expression in the HDAC3-knockdown FaDu cells were investigated by Real-time qPCR and ChIP-qPCR.Results:Compared with normoxic condition,the relative expression levels of FOXP3 mRNA in FaDu and OECM-1 cells under hypoxic condition were decreased by 65.6% and 75.7% (P<0.01).The Western blotting results indicated that compared with normoxic condition,the expression levels of FOXP3 protein in FaDu and OECM-1 cells under hypoxic condition were decreased.The ChIP experiment results showed that compared with normoxic condition,the levels of H3K4ac and H3K4me3 on FOXP3 gene promoter in FaDu cells were decreased under hypoxic condition (P<0.01),while the H3K27me3 level was not changed.In HDAC3-knockdown FaDu cells,compared with control cells,the inhibitory rates of the expressions of H3K4ac and H3K4me3 on FOXP3 gene promoter under hypoxia condition were decreased (P<0.05),so did expressions the FOXP3 mRNA expression (P<0.05).Conclusion:Hypoxia could suppress the expression of FOXP3 by HDAC3-mediated down-regulation of H3K4ac on FOXP3 gene promoter in the human OSCC cells.
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Objective To evaluate the inter-fraction setup error during the treatment with megavoltage computed tomography (MVCT) and provide theoretical basis for clinical target volume-planning target volume (CTV-PTV) margins for nasopharyngeal carcinoma (NPC) patients treated with tomotherapy.Methods Thirty-seven consecutive NPC patients treated with tomotherapy were prospectively enrolled for the study between February 2015 and September 2015.For each patient,one MVCT scan was obtained after conventional positioning,online correction and tomotherapy delivery daily,and the scan was registered to the planning CT to determine inter-fraction setup error.The expanding margin for PTV (MPTV) was calculated with the recipe:MPTV =2.5∑ + 0.76 (∑:systematic error;6:random error).Results The average absolute errors of the inter-fraction were (2.102 ± 0.040 6) mm,(1.490 ± 0.034 8) mm,(1.306 ± 0.335) mm and (1.392 ± 0.038 4) ° in the three dimensions.Gradual increases in both inter-fraction three-dimensional displacement were observed with time and treatment (P ＜ 0.05).The total MPTV ac counting for inter-error were 3.467 5 mm,2.979 5 mm and 2.888 5 mm.Conclusions Tomotherapy irradiation technology personalized MPTV should be adopted for the design of tomotherapy plan.Displacement increased as a function of time.
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Objective To explore the inter-fraction setup errors and affecting factors from data of daily fan-beam megavoltage computed tomography(MVCT). Methods A total of 37consecutive NPC patients treated with tomotherapy were hospitalized during the period of February 2015 to September 2015. For each patient,one MVCT scan was obtained after conventional positioning ,online correction and tomotherapy delivery daily ,and the scans were put into the planning computed tomography to determine inter-fraction setup errors. The MPTV was calculated with the equation:MPTV=2.5∑+0.7σ(∑:systematic error;σ:random error). Results The average absolute errors of the inter-fraction were(2.102 ± 0.0406)mm,(1.490 ± 0.0348)mm,(1.306 ± 0.335)mm and(1.392 ± 0.0384)° at three dimensions. The total MPTV accounting for inter-error was 3.4675 mm,2.9795 mm,and 2.8885 mm. Gradual increases in both inter-fraction three-dimensional displacement were observed with time and treatment(P < 0.05). Univariate analysis revealed that weight loss and retraction of neck lymph nodes were affecting factors of set-up errors. Conclusions 3 mm margins uniformly expended from clinical target volume to planning target volume may not be suitable. The personalized margin should be adopted for the design of IMRT planning. Displacement increases as a treatment course is prolonged.
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Objective To study the factors influencing the outcome of patients suffering from in-hospital ventricular fibriUation (IHVF), as there have been few studies focusing on this topic. Methods Patients with IHVF collected in a single cardiac center were classified into a successful group and a failure group. Data relevant to the predicting factors of the two groups were compared. Results There were 206 events in the analysis. The most common underlining disease was coronary artery disease (CAD), especially acute myocardial infarction (AMI). On multiple logistic regression analysis, it was shown that the independent predictors for failure of defebriUation were higher NYHA class (OR 1.7, 95% CI 1.3-2. 2,P <0.001), higher blood potassium level (OR 2.9, 95% CI 1.9-4.3, P =0.007) and adrenaline usage (OR 25.0, 95% CI 11.5-55. 1, P <0.001). In a AMI sub-group, 56. 9% of the IHVF events occurred within the first day of AMI, and the occurrence descended with time going on within 2 weeks. Before the occurrence of IHVF, the patients with right coronary artery as the infarction related artery (IRA) often suffered from(8/9, 88.9%) bradycardia (R-R interval > 1 s), but those with left anterior descending artery as IRA often showed (8/12, 66.7%) tachycardia (RR interval < 0.6 s). Conclusions The common disease causing IHVF is CAD. The worse the heart function, the higher the rate of IHVF and the worse theprognosis. It IHVF not induced by hypokalemia and use of adrenaline in resuscitation predict lower successful defibrillation rate.
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Objectives: To assess the feasibility and stability of right ventricular outflow tract (ROVT) pacing under current technology by comparing the results of ROVT pacing with the traditional right ventricular apex (RVA) pacing. Methods: A total of 42 patients (at mean age of 63.5±10.4 years) without structural heart disease were randomly divided into two groups. RVA pacing group (n=14),and RVOT pacing group(n=28). An active fixation lead was implanted in all patients whose pacemaker could automatically measure the pacing threshold every day. The operation time,X-ray exposure time and lead parameters detected during the operation were collected to evaluate the feasibility of RVOT pacing. The complications related to lead and implantation procedure and the trend of threshold change during the follow-up time were used to assess the stability of RVOT pacing.Results: There were no statistic differences between RVA pacing group and RVOT pacing group in terms of operation time,X-ray exposure time and lead parameters. In RVOT group,the change of threshold during acute period was similar to those in RVA group (P=0.23). Chronic pacing threshold was also comparable between two groups,mean threshold at 6 months follow-up time was 0.55±0.11V and 0.54±0.09V at 0.4 pulse width in RVA group and RVOT group respectively (P=0.787).Conclusion: RVOT pacing was feasible and stable in operation time and lead characteristics compared with the conventional RVA pacing under current pacing technology.
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Objective Right ventricular outflow tract septum has become widely used us an electrode placement site. However, data concerning lead performances and complications for lead repositioning with this technique were scant. The purpose of this study was to observe long-term lead performances and complications of right ventricular outflow tract septal pacing and provide evidences for choosing an optimal electrode implantation site. Methods Thirty-six patients with septal active electrode implantation and 39 with apical passive electrode implantation were enrolled in this study. Pacing threshold, R-wave sensing, lead impedance, pacing QRS width and pacing-related compli-cations for two groups at implantation and follow-up were compared. Results There were higher pacing threshold and shorter pacing QRS width at implantation in the septal group compared with the apical group. There were no differences between the septal and the apical groups in pacing threshold, R-wave sensitivity, lead impedance and pace-related complication during a follow-up. Conclusions Right ventricular outflow tract septum could be used as a first choice for implantation site because it had long-term stable lead performances and no serious complications compared with the traditional apical site.
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Objective Atrioventricular block (AVB) is a common and serious arrhythmia. At present, there is no perfect method of treatment for this kind of arrhythmia. The purpose of this study was to regenerate cardiac atrioventricular conduction by autologous transplantation of bone marrow mesenchymal stem cells (MSCs), and explore new methods for therapy of atrioventricular block. Methods Eleven Mongrel canines were randomized to MSCs transplantation (n=6) or control (n=5) group. The models of permanent and complete AVB in 11 canines were established by ablating His bundle with radiofrequency technique. At 4 weeks after AVB, bone marrow was aspirated from the iliac crest. MSCs were isolated and culture-expanded by means of gradient centrifugal and adherence to growth technique, and differentiated by 5-azacytidine in vitro. Differentiated MSCs (1ml, 1.5×107cells) labeled with BrdU were autotransplanted into His bundle area of canines by direct injection in the experimental group, and 1ml DMEM in the control group. At 1-12 weeks after operation,the effects of autologous MSCs transplantation on AVB models were evaluated by electrocardiogram, pathologic and immunohistochemical staining technique. Results Compared with the control group, there was a distinct improvement in atrioventricular conduction function in the experimental group. MSCs transplanted in His bundle were differentiated into analogous conduction system cells and endothelial cells in vivo, and established gap junction with host cardiomyocytes. Conclusions The committed-induced MSCs transplanted into His bundle area could differentiate into analogous conduction system cells and improve His conduction function in canine AVB models.
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Background and objectives Right ventricular apical (RVA) pacing has been reported impairing left ventricular (LV)performance. Alternative pacing sites in right ventricle (RV) has been explored to obtain better cardiac function. Our study was designed to compare the hemodynamic effects of right ventricular septal (RVS) pacing with RVA pacing. Methods Ten elderly patients with chronic atrial fibrillation (AF) and long RR interval or slow ventricular response (VR) received VVI pacing. The hemodynamic difference between RVS and RVA pacing were examined by transthoracic echocardiography (TTE). Results Pacing leads were implanted successfully at the RVA and then RVS in all patients without complication. The left ventricular (LV) parameters,measured during RVA pacing including left ventricular ejection fraction (LVEF), FS, stroke volume (SV) and peak E wave velocity (EV) were decreased significantly compared to baseline data, while during RVS pacing, they were significantly better than those during RVA pacing. However, after 3-6 weeks there was no statistical significant difference between pre- and post- RVS pacing.Conclusions The LV hemodynamic parameters during RVA pacing were significantly worse than baseline data. The short term LV hemodynamic parameters of RVS pacing were significantly better than those of RVA pacing; RVS pacing could improve the hemodynamic effect through maintaining normal ventricular activation sequence and biventricular contraction synchrony in patients with chronic AF and slow ventricular response.
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In order to provide the maximum benefit of cardiac resynchronization therapy (CRT), we tried to use an echocardiography method to optimize the atrioventricular and interventricular delay. Methods The study included 6 patients who underwent implantation of biventricular pacemakers for drug-resistant heart failure. Two-dimensional echocardiography and tissue Doppler imaging were carried out before and after the pacemaker implantation. The optimal AV delay was defined as the AV delay resulting in maximum timevelocity integral (TVI) of transmitral filling flow, the longest left ventricular filling time (LVFT) and the minimum mitral regurgitation(MR). The optimal VV delay was defined as the VV delay producing the maximum LV synchrony and the largest aortic TVI. Results CRT was successfully performed in all patients. After pacemaker implantation, an acute improvement in left ventricular ejection fraction (LVEF) was observed from 26.5% to 35%. Meanwhile, the QRS duration decreased from 170ms to 150ms. The optimal AV delay was programmed at 130, 120, 120, 120, 150 and 110ms respectively with heart rate corrected, LVFT significantly lengthened and TVI of MR decreased (non-optimal vs optimal AV delay: LVFT: 469ms vs 523ms; TVI of MR: 16.43cm vs 13.06cm, P＜0.05). The optimal VV delay was programmed at 4, 4, 4, 8, 12 and 8ms with LV preactivation respectively. Programming the optimal VV delay increased the aortic TVI from 17.33cm up to 21.42cm (P＜0.05). In the septal and lateral wall, peak systolic velocities improved from2.70cm/s to 3.02cm/s (P＞0.05) and froml.31cm/s to 2.50cm/s (P＜0.05) respectively. The septal-to-lateral delay in peak velocity improved from 56.4ms to 13.3ms after CRT (P＜0.01). Conclusions Optimization of AV and VV delays may further enhance the efficacy of CRT. However, there was interindividual variability of optimal values, warranting individual patient examination.
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<p><b>OBJECTIVE</b>To analyze the unipolar electrogram from successful and unsuccessful ablation sites of focal atrial tachycardia (AT), and to evaluate its value in the identification of successful targets.</p><p><b>METHODS</b>Fifteen consecutive patients with focal AT were referred for radiofrequency catheter ablation (RFCA). Both unipolar (from the tip electrode of ablating catheter) and bipolar (from the distal pair of electrode of ablating catheter) electrograms were used to identify the ablation targets of focal AT.</p><p><b>RESULTS</b>Successful ablation was echieved in 14 patients. Radiofrequency energy was delivered at a total of 27 sites. The bipolar electrograms associated with successful ablation sites showed earlier atrial deflection relative to P wave onset (36 ms +/- 15 ms vs 30 ms +/- 11 ms, P < 0.05) than the electrograms associated with failed ablation sites. At the 14 successful ablation sites, the unipolar electrograms displayed a completely negative atrial wave ("QS" morphology) beginning with intrinsic deflection. However, at the 13 unsuccessful ablation sites, a "rS" morphology of atrial wave was shown on the unipolar electrogram.</p><p><b>CONCLUSION</b>The "QS" morphology of the atrial wave on unipolar electrograms appears to represent a reliable marker for identifying the successful ablation targets of focal AT, with a high sensitivity and specificity.</p>
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Adolescent , Adult , Aged , Child , Female , Humans , Male , Middle Aged , Catheter Ablation , Methods , Electrocardiography , Retrospective Studies , Tachycardia , Diagnosis , General SurgeryABSTRACT
Objective To study the relationship between obstructive sleep apnea syndrome(OSAS) in the elderly and the occurrence and development of arrhythmia. Methods A total of 120 OSAS patients and 40 normal controls were selected and their polysomnography(PSG) or dynamic blood oxygen and analyzed holter were monitored. Results The total number of the reduction in apnta hypopnea index (AHI) and arterial orygen saturation (SaO 2) over 0.04 and the lasted period during SaO 20.05), while the incidences of the intermediate and serious groups significantly increased(P