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PURPOSE: The etiology of postmenopausal recurrent urinary tract infection (UTI) is not completely known, but the urinary microbiome is thought to be implicated. We compared the urinary microbiome in menopausal women with recurrent UTIs to age-matched controls, both in the absence of acute infection. MATERIALS AND METHODS: This is a cross-sectional analysis of baseline data from 64 women enrolled in a longitudinal cohort study. All women were using topically applied vaginal estrogen. Women >55 years of age from the following groups were enrolled: 1) recurrent UTIs on daily antibiotic prophylaxis; 2) recurrent UTIs not on antibiotic prophylaxis; and 3) age-matched controls without recurrent UTIs. Catheterized urine samples were collected at least 4 weeks after last treatment for UTI and at least 6 weeks after initiation of vaginal estrogen. Samples were evaluated using expanded quantitative urine culture (EQUC) and 16S rRNA gene sequencing. RESULTS: With EQUC, there were no significant differences in median numbers of microbial species isolated among groups (p=0.96), even when considering Lactobacilli (p=0.72). However, there were trends towards different Lactobacillus species between groups. With 16S rRNA sequencing, the majority of urinary samples contained Lactobacilli, with non-significant trends in relative abundance of Lactobacilli among groups. Using a Bayesian analysis, we identified significant differences in anaerobic taxa associated with phenotypic groups. Most of these differences centered on Bacteroidales and the family Prevotellaceae, though differences were also noted in Actinobacteria and certain genera of Clostridiales. CONCLUSIONS: Associations between anaerobes within the urinary microbiome and postmenopausal recurrent UTI warrants further investigation.

The high prevalence of somatic symptom disorder (SSD) led to cumulative burdens to the medical system. However, the pathogenesis of this disease still remains unclear. Graph theoretical analysis discovered altered network topology across various psychiatric disorders, yet alteration in the topological structure of brain functional network in SSD patients is still unexplored. Catastrophizing is a common cognitive distortion in SSD. We hypothesize that the network topological metrics of SSD should be altered, and should correlate with catastrophizing scales. 32 medication-naïve, first-episode SSD patients and 30 age, gender matched HCs were recruited. The 17-item Hamilton Depression Rating Scale (HAMD-17), Hamilton Anxiety Rating Scale (HAMA) and Cognitive Emotion Regulation Questionnaire (CERQ) were accessed. Functional MRI were scanned and brain functional networks were constructed based on 166 anatomically cerebrum regions from the automated anatomical labeling 3 (AAL3) template. Network topological metrics were calculated and compared between the two groups. Correlation between these metrics and clinical scales were also calculated. Network global efficiency of SSD was significantly lower than that of HC. Nodal global efficiency of the left subgenual anterior cingulate cortex (sgACC) of SSD was significantly lower than that of HC. FCs between the left sgACC and other 21 seed nodes were significantly declined in SSD in comparison with HC. In SSD group, HAMD total score was significantly negatively correlated with the connection between the left medial superior frontal gyrus and the left sgACC. CERQ catastrophizing score was significantly negatively correlated with nodal global efficiency of left sgACC and with the FCs between the left sgACC and other 13 seed nodes. Catastrophizing could reflect the specific sgACC-centered dysfunction of brain network global efficiency of SSD. The left sgACC may be a future treatment target of dealing with catastrophizing, which is a core cognitive distortion of SSD.

Introduction and objectives The aging population is expected to reach 2 billion by 2050, but the impact of somatic symptom disorder (SSD) on the elderly has been insufficiently addressed. We aimed to clarify the prevalence of SSD in China and to identify physical and psychological differences between the elderly and non-elderly. Methods In this prospective multi-center study, 9020 participants aged (2206 non-elderly adults and 6814 elderly adults) from 105 communities of Shanghai were included (Assessment of Somatic Symptom in Chinese Community-Dwelling People, clinical trial number NCT04815863, registered on 06/12/2020). The Somatic Symptom Scale-China (SSS-CN) questionnaire was used to measure SSD. Depressive and anxiety disorders were assessed by the Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7), respectively. Results The prevalence of SSD in the elderly was higher than that in the non-elderly (63.2% vs. 45.3%). The elderly suffered more severe SSD (20.4% moderate and severe in elderly vs. 12.0% in non-elderly) and are 1.560 times more likely to have the disorder (95%CI: 1.399–1.739; p Conclusions With higher prevalence of common physical problems (including hypertension, diabetes mellitus and cardio/cerebrovascular disease), the elderly in Shanghai are more vulnerable to have SSD and are more likely to suffer from comorbid depressive and anxiety disorders. SSD screening should be given more attention in the elderly, especially among older females with several comorbid physical diseases.

ObjectiveAn approach for assessing the urinary microbiome is 16S rRNA gene sequencing, where analysis methods are rapidly evolving. This re-analysis of an existing dataset aimed to determine whether updated bioinformatic and statistical techniques affect clinical inferences.MethodsA prior study compared the urinary microbiome in 123 women with mixed urinary incontinence (MUI) and 84 controls. We obtained unprocessed sequencing data from multiple variable regions, processed operational taxonomic unit (OTU) tables from the original analysis, and de-identified clinical data. We re-processed sequencing data with DADA2 to generate amplicon sequence variant (ASV) tables. Taxa from ASV tables were compared to the original OTU tables; taxa from different variable regions after updated processing were also compared. Bayesian graphical compositional regression (BGCR) was used to test for associations between microbial compositions and clinical phenotypes (e.g., MUI versus control) while adjusting for clinical covariates. Several techniques were used to cluster samples into microbial communities. Multivariable regression was used to test for associations between microbial communities and MUI, again while adjusting for potentially confounding variables.ResultsOf taxa identified through updated bioinformatic processing, only 40% were identified originally, though taxa identified through both methods represented >99% of the sequencing data in terms of relative abundance. Different 16S rRNA gene regions resulted in different recovered taxa. With BGCR analysis, there was a low (33.7%) probability of an association between overall microbial compositions and clinical phenotype. However, when microbial data are clustered into bacterial communities, we confirmed that bacterial communities are associated with MUI. Contrary to the originally published analysis, we did not identify different associations by age group, which may be due to the incorporation of different covariates in statistical models.ConclusionsUpdated bioinformatic processing techniques recover different taxa compared to earlier techniques, though most of these differences exist in low abundance taxa that occupy a small proportion of the overall microbiome. While overall microbial compositions are not associated with MUI, we confirmed associations between certain communities of bacteria and MUI. Incorporation of several covariates that are associated with the urinary microbiome improved inferences when assessing for associations between bacterial communities and MUI in multivariable models.

ObjectiveAn approach for assessing the urinary microbiome is 16S rRNA gene sequencing, where a segment of the bacterial genome is amplified and sequenced. Methods used to analyze these data are rapidly evolving, although the research implications are not known. This re-analysis of an existing dataset aimed to determine the impact of updated bioinformatic and statistical techniques.MethodsA prior Pelvic Floor Disorders Network (PFDN) study compared the urinary microbiome in 123 women with mixed urinary incontinence (MUI) and 84 controls. We used the PFDN’s unprocessed sequencing data of V1-V3 and V4-V6 16S variable regions, processed operational taxonomic unit (OTU) tables, and de-identified clinical data. We processed sequencing data with an updated bioinformatic pipeline, which used DADA2 to generate amplicon sequence variant (ASV) tables. Taxa from ASV tables were compared to OTU tables generated from the original processing; taxa from different variable regions (e.g., V1-V3 versus V4-V6) after updated processing were also compared. After updated processing, data were analyzed with multiple filtering thresholds. Several techniques were tested to cluster samples into microbial communities. Multivariable regression was used to test for associations between microbial communities and MUI, while controlling for potentially confounding variables.ResultsOf taxa identified through updated bioinformatic processing, only 40% were identified originally, though taxa identified through both methods represented >99% of sequencing data in terms of relative abundance. When different 16S rRNA gene regions were sequenced from the same samples, there were differences noted in recovered taxa. When the original clustering methods were applied to reprocessed sequencing data, we confirmed differences in microbial communities associated with MUI. However, when samples were clustered with a different methodology, microbial communities were no longer associated with MUI.ConclusionsUpdated bioinformatic processing techniques recover many different taxa compared to prior techniques, though most of these differences exist in low abundance taxa that occupy a small proportion of the overall microbiome. Detection of high abundance taxa are not significantly impacted by bioinformatic strategy. However, there are different biases for less abundant taxa; these differences as well as downstream clustering methodology and filtering thresholds may affect interpretation of overall results.

Recurrent urinary tract infections (UTI) are highly prevalent in postmenopausal women, where vaginal estrogen and prophylactic antibiotics are used for treatment. The etiology of recurrent UTIs is not completely known, but the urinary microbiome is thought to be implicated. Thus, we aimed to compare the “steady state” urinary microbiome in three groups of menopausal women who were all using topically-applied vaginal estrogen: 1) women with recurrent UTIs on daily antibiotic prophylaxis; 2) women with recurrent UTIs not on antibiotic prophylaxis; and 3) age-matched controls without recurrent UTIs. Here we present a cross-sectional analysis of baseline data from 64 women enrolled in a longitudinal cohort study. Catheterized urine samples were collected > 4 weeks after last treatment for UTI. Samples were evaluated using expanded quantitative urine culture (EQUC) and 16S rRNA gene sequencing. With EQUC techniques, there were no significant differences in the median numbers of microbial species isolated among groups (p=0.96), even when considering Lactobacilli (p=0.72). However, there were trends towards different Lactobacillus species between groups. With sequencing the overwhelming majority of urinary samples contained Lactobacilli, with non-significant trends in relative abundance of Lactobacilli among groups. Using a Bayesian regression analysis for compositional data, we identified significant differences in anaerobic taxa that were associated with phenotypic groups. Most of these differences centered on Bacteroidales and the family Prevotellaceae, though differences were also noted in Actinobacteria and certain genera of Clostridiales. Associations between anaerobes within the urinary microbiome and recurrent UTI warrants further investigation.IMPORTANCEIn menopausal women with recurrent urinary tract infections (UTIs) compared to those without, the abundance of Lactobacillus within the urinary microbiome is not significantly different when vaginal estrogen is regularly used. In this population, Lactobacillaceae were identified in 97% of urine samples using culture-independent techniques. However, with expanded urine cultures, women with recurrent UTIs taking daily antibiotics had a disproportionately low amount of L. gasseri/L. acidophilus compared to the other phenotypic groups. These findings support the theory that certain Lactobacillus species may be more important than others in the pathophysiology of postmenopausal recurrent UTIs. Furthermore, when using culture-independent techniques to explore urinary microbiota across phenotypic groups, we identified differences in multiple anaerobic taxa. Taken together, these results suggest that altered ratios of anaerobes and certain Lactobacillus species within the urinary microbiome may be implicated in postmenopausal recurrent UTI.

IntroductionThe detection rate of somatic symptom disorder (SSD) in general hospitals is unsatisfactory. Self-report questionnaires that assess both somatic symptoms and psychological characteristics will improve the process of screening for SSD. The Somatic Symptom Scale-China (SSS-CN) questionnaire has been developed to meet this urgent clinical demand. The aim of this research is to validate the self-reported SSS-CN as a timely and practical instrument that can be used to identify SSD and to assess the severity of this disorder.Methods and analysisAt least 852 patients without organic disease but presenting physical discomfort will be recruited at a general hospital. Each patient will undergo aDiagnostic and Statistical Manual of Mental Disorders, 5th Edition(DSM-5)-guided physician diagnosis, including disease identification and severity assessment, as the reference standard. This research will compare the diagnostic performance of the SSS-CN for SSD, the Patient Health Questionnaire-15 (PHQ-15) and other SSD-related questionnaires. Statistical tests to measure the area under the curve (AUC) and volume under the surface of the receiver operating curve will be used to assess the accuracy of the SSD identification and the severity assessment, respectively. In addition to this standard diagnostic study, we will conduct follow-up investigations to explore the effectiveness of the SSS-CN in monitoring treatment effects.Ethics and disseminationEthical approval was obtained from the Renji Hospital Human Research Ethics Committee, approval number 2 015 016. The findings of this study will be disseminated via peer-reviewed journals and presented at international conferences.Trial registration numberNCT03513185.

Aims Frequent premature atrial contractions (PACs) are associated with increased risk of atrial fibrillation (AF), stroke, and death. This study aimed to explore the electrophysiological features of PACs with and without inducing AF and to evaluate the effectiveness of catheter ablation for PACs. Methods and results Thirty-five consecutive patients with symptomatic, frequent, and drug-refractory PACs in the absence of AF (group A) and 35 patients with PACs-induced AF (group B) were enrolled. Coupling intervals (CoIs) of PACs were compared. Premature atrial contractions were mapped by the point-by-point and/or circular mapping technique. Focal ablation or pulmonary vein/superior vena cava isolation was applied as appropriate. A total of 35 ectopic foci were identified in group A. The majority of them were at pulmonary vein (PV) ( n = 7), crista terminalis ( n = 6), and para-Hisian area ( n = 6). In group B, ectopic foci were in left-sided PVs in 21 patients, in right-sided PVs in 13 patients, and in SVC in 1 patient. There was significant difference in CoIs of PACs triggering AF and those from PVs and non-PV areas but without causing AF (362.8 ± 23.0 ms vs. 470.6 ± 60.1 ms vs. 515.6 ± 77.2 ms, P < 0.001). Premature atrial contractions were abolished in 32 of 35 patients from group A and in all patients from group B. At the end of follow-up, 29 patients in group A and 28 patients in group B were free of recurrence (off antiarrhythmic drugs) after the initial ablation ( P = 0.97). Conclusions Frequent PACs in the absence of AF were characterized as having their predilection sites and longer CoIs than those inducing AF. Catheter ablation was effective to eliminate symptomatic, frequent, and drug-refractory PACs.

Circulating primary bile acid was involved in the regulation of cardiac ionic channel currents and ventricular myocyte apoptosis, but it was unknown whether or not it played a role in structural remodeling of AF. This study was aimed to testify the hypothesis that elevated chenodeoxycholic acid (CDCA) concentration correlated with left atrial low voltage area (LVA) and could induce apoptosis of atrial myocytes in AF. Serum concentrations of 12 types of bile acids were determined in patients with paroxysmal (n = 21), persistent AF (n = 20), and type A pre-excitation and paroxysmal supraventricular tachycardia (PSVT) (n = 19) and were correlated with LVA in AF, which was obtained by electroanatomical mapping during ablation. Additionally, the impact of CDCA incubation on apoptosis of mouse atrial myocytes was evaluated. Serum levels of CDCA and cholic acid were significantly higher in AF than in PSVT. CDCA serum concentration was significantly higher in persistent AF than in paroxysmal AF. CDCA serum level was positively correlated with the size (r = 0.78, P

The prevalence, risk factors of left atrial low voltage areas (LVA) in paroxysmal atrial fibrillation (PAF) and the impact of LVA on the effectiveness of circumferential pulmonary vein isolation (CPVI) were not fully clarified.One hundred fifty patients (mean age 64.7 years, 89 males) with PAF were consecutively enrolled to undergo CPVI. Prior to ablation a contact force sensing ablation catheter was utilized for LVA mapping in sinus rhythm. The patients were graded based on the proportion of LVA (LVA%): non LVA, mild (LVA% ≤ 10%), moderate (LVA% 10%-20%) and severe (LVA% ≥ 20%), and were followed up for 12 months after initial CPVI.There were 56 in non LVA, 54 in mild LVA, 22 in moderate LVA and 18 in severe LVA. The prevalence of LVA was 62.7% in this PAF cohort, with the most frequent localization at anterior free wall (35.3%), PV antrum (22%) and septum (14.7%). Female gender (OR 3.634, 95% CI 1.704-7.751, P = 0.001) and left atrial surface area (LASA) (OR 1.024, 95% CI 1.000-1.048, P = 0.048) were risk factors of LVA. LVA% exceeding10% was associated with poor effectiveness of CPVI. LVA grade (HR 1.633, 95% CI 1.122-2.378, P = 0.011) was an independent predictor for AF recurrence after initial ablation.LVA affected60% of patients with PAF. Female gender and LASA were two risk factors of LVA. LVA grade was an independent predictor for AF recurrence following CPVI.

Background: The aim of this study was to establish a score system derived from clinical, echocardiographic and electrocardiographic indexes and evaluate its clinical value for cardiac resynchronization therapy (CRT) patient selection. Methods: Ninety-three patients receiving CRT were enrolled. A patient selection score system was generated by the clinical, echocardiographic and electrocardiographic parameters achieving a significant level by univariate and multivariate Cox regression model. The positive response to CRT was a left ventricular end systolic volume decrease of ≥ 15% and not reaching primary clinical endpoint (death or re-hospitalization for heart failure) at the end of follow-up. Results: Thirty-nine patients were CRT non-responders (41.94%) and 54 were responders (58.06%). A 4-point score system was generated based on tricuspid annular plane systolic ex­cursion (TAPSE), longitudinal strain (LS), and complete left bundle branch block (CLBBB) combined with a wide QRS duration (QRSd). The sensitivity and specificity for prediction of a positive response to CRT at a score > 2 were 0.823 and 0.850, respectively (AUC: 0.92295% CI 0.691–0.916, p< 0.001). Conclusions: A patient selection score system based on the integration of TAPSE, LS and CLBBB combined with a wide QRSd can help to predict positive response to CRT effectively and reliably.

An important task in microbiome studies is to test the existence of and give characterization to differences in the microbiome composition across groups of samples. Important challenges of this problem include the large within-group heterogeneities among samples and the existence of potential confounding variables that, when ignored, increase the chance of false discoveries and reduce the power for identifying true differences. We propose a probabilistic framework to overcome these issues by combining three ideas: (i) a phylogenetic tree-based decomposition of the cross-group comparison problem into a series of local tests, (ii) a graphical model that links the local tests to allow information sharing across taxa, and (iii) a Bayesian testing strategy that incorporates covariates and integrates out the within-group variation, avoiding potentially unstable point estimates. With the proposed method, we analyze the American Gut data to compare the gut microbiome composition of groups of participants with different dietary habits. Our analysis shows that (i) the frequency of consuming fruit, seafood, vegetable, and whole grain are closely related to the gut microbiome composition and (ii) the conclusion of the analysis can change drastically when different sets of relevant covariates are adjusted, indicating the necessity of carefully selecting and including possible confounders in the analysis when comparing microbiome compositions with data from observational studies. Supplementary materials for this article, including a standardized description of the materials available for reproducing the work, are available as an online supplement.

Background Frequent premature ventricular complexes (PVCs) are associated with a reversible form of LV dysfunction. Objective We performed a meta-analysis to evaluate the effects of catheter ablation on improvement of LV function in patients with frequent PVCs. Methods We searched MEDLINE for cohort studies of patients who underwent catheter ablation of frequent PVCs. LVEF both before and postablation was reported. The endpoints were changes from baseline in both LVEF and LV end-diastolic diameter (LVEDd) postablation. Quantitative analysis of continuous variables was performed according to random effect methods by MetaAnalyst Beta 3.13 software. Association between site of origin (SOO) of PVCs and degree of LVEF improvement was evaluated by meta-regression using STATA V.12.0 software. Subgroup analysis of patients with LV dysfunction at baseline was performed. Results Fifteen studies with a total of 712 patients were included. The mean PVC burden before catheter ablation was 24% (95% CI 19% to 29%). The long-term success rate of PVC ablation ranged from 66% to 90%. The overall mean increase from baseline in LVEF postablation was 7.7% (95% CI 6.1% to 9.4%) and the overall mean decrease in LVEDd was −4.6 mm (95% CI −6.0 to −3.1 mm). Meta-regression showed no significant association of SOO of PVCs with the degree of postablation LVEF improvement. Subgroup analysis showed that the overall mean increase from baseline in LVEF postablation was 12.4% (95% CI 8.1% to 16.6%) and the overall mean decrease in LVEDd was −4.8 mm (95% CI −6.2 to −3.4 mm) in patients with LV dysfunction at baseline. Conclusions Ablation of frequent PVCs improves cardiac function, especially for patients with LV dysfunction.

Background Although left ventricular pacing (LVP) leads to a greater acute hemodynamic response than does biventricular pacing (BVP), the long-term effects are diverse. We aimed to assess the efficacy of LVP and BVP in patients undergoing cardiac resynchronization therapy and determine which patients would benefit more from LVP or BVP. Methods Randomized controlled trials that compared left and biventricular pacing were retrieved from MEDLINE and analyzed for changes in cardiac function and dimensions, cardiac resynchronization therapy response, and electromechanical effects. Results A total of 811 patients were included from 9 trials. After a mean follow-up, a shorter QRS duration (−40.92 milliseconds; 95% confidence interval [CI], −64.50 to −17.34; P = 0.0007), and improved left ventricular dimensions were observed in the BVP group compared with the LVP group. Moreover, the BVP group had a longer 6-minute hall walk (6MHW) test (37.19 m; 95% CI, 4.72 to 69.67; P = 0.02). Conclusion Our results indicate that BVP results in a better electromechanical effect and leads to a better 6MHW test. For all other test criteria, LVP showed a benefit equal to that of BVP. Thus, there is currently insufficient evidence to advocate for LV-only pacing.

We introduce a method—called Fisher exact scanning (FES)—for testing and identifying variable dependency that generalizes Fisher’s exact test on 2 × 2 contingency tables to R × C contingency tables and continuous sample spaces. FES proceeds through scanning over the sample space using windows in the form of 2 × 2 tables of various sizes, and on each window completing a Fisher’s exact test. Based on a factorization of Fisher’s multivariate hypergeometric (MHG) likelihood into the product of the univariate hypergeometric likelihoods, we show that there exists a coarse-to-fine, sequential generative representation for the MHG model in the form of a Bayesian network, which in turn implies the mutual independence (up to deviation due to discreteness) among the Fisher’s exact tests completed under FES. This allows an exact characterization of the joint null distribution of the p-values and gives rise to an effective inference recipe through simple multiple testing procedures such as Šidák and Bonferroni corrections, eliminating the need for resampling. In addition, FES can characterize dependency through reporting significant windows after multiple testing control. The computational complexity of FES is approximately linear in the sample size, which along with the avoidance of resampling makes it ideal for analyzing massive datasets. We use extensive numerical studies to illustrate the work of FES and compare it to several state-of-the-art methods for testing dependency in both statistical and computational performance. Finally, we apply FES to analyzing a microbiome dataset and further investigate its relationship with other popular dependency metrics in that context. Supplementary materials for this article are available online.

Tracking-Learning-Detection(TLD) algorithm has the advantages of high speed, high accuracy of tracking rate and self-detection mechanism. However the sensitivity to illumination variation and background clutter leads to drift even miss for TLD algorithm under the complex environment. An improved TLD visual tracking algorithm based on depth information is proposed, which is improved from three aspects. The first is that a foreground extraction algorithm based on denoised depth data is adopted to extract the region of interest. Second, a sophisticated detection of blob approach is used to narrow down the searching area. And the third is that the non-maximal suppression strategies are applied to optimize the result. The experimental results show that the time complexity of proposed is decreased and the robustness is upgrade under challenging circumstances.

The arrival and departure time sampling of the flight is one of the key information for parking bays monitoring to avoid conflict. Nowadays the time is reported and recorded by hand in many airports, which fault and delay reports may happen. Safety risks and lower efficiency cannot be neglected. This paper presents a robust vision-based method to automatically sample the arrival and departure time on the bays by flight move tracking and keep the flight under intelligent surveillance with the camera in the ramp. Based on the Gaussian Mixture Model algorithm, the improved method provided successfully solves the light changing disturbance and other moving object influence with Optical Flow Methods, which has been applied in the eighty seven bays of Shanghai Hongqiao International Airport that is one of the major airports in China. The practical result shows that the accuracy rate is above 90% and the missed alarm rate below 1%.

Background The early- to mid-term impact of bone-marrow-derived stem cells (BMC) on diastolic function and exercise capacity after acute myocardial infarction (AMI) remains controversial. We performed a systematic analysis to assess whether BMC transfer is related to an early improvement in diastolic function and exercise capacity after AMI. Methods Randomized controlled trials (RCTs) of BMC therapy after AMI were extracted from MEDLINE, EMBASE and CENTRAL and analyzed for a change in tissue Doppler annular early (Ea) and late diastolic (Aa) velocities, mitral inflow E velocity to tissue Doppler Ea ( E /Ea) ratio, exercise time and exercise capacity. Results A total of 365 patients were included from 6 trials. A greater improvement was observed in the E /Ea ratio after 1 year in the BMC group compared to the control group. Additionally, the BMC-treated patients had a larger improvement in exercise time, ventilation/CO 2 production (VE/VCO 2 slope) and respiratory exchange ratio (RER) after 1 year. Conclusion The results indicate that intracoronary BMC treatment in AMI patients leads to a mid-term improvement in diastolic function and exercise capacity.

Background The most effective approach for long-standing persistent atrial fibrillation (LPAF) ablation remained undetermined. Our goal was to explore the heterogeneous left atrial substrate in patients with LPAF and to evaluate the effectiveness of a novel individualized substrate modification (ISM) approach in LPAF ablation. Methods One hundred and twenty-four patients with LPAF were randomized to ISM group ( n =64) or stepwise ablation (SA) group ( n =60). After pulmonary vein isolation, ISM was performed in the ISM group and SA was applied in the SA group. The clinical effectiveness after a single and a repeated procedure was compared. Results The total procedural time was significantly shorter in ISM than that in SA. In the ISM group, mild left atrial substrate was observed in 17 (27.4%), moderate in 26 (41.9%) and severe in 19 (30.6%) patients after successful cardioversion of the 62 patients. The intention-to-treat analysis showed that sinus rhythm was maintained in 65.5% of patients in the ISM group and in 45.0% of patients in the SA group after a single procedure, P =0.04. Atrial tachycardia (AT) recurred in 5 of 22 in the ISM group and in 20 of 33 in the SA group, P =0.01. After a repeated procedure, 75% of patients in the ISM group and 63.3% of patients in the SA group were free of further recurrence, P =0.16. Conclusions Left atrial substrate varied noticeably in patients with LPAF. The ISM approach was superior to SA approach in terms of procedural time, recurrence rate of AT and clinical effectiveness after a single procedure. However, they yielded comparable outcomes after a repeated procedure.

Persistent left superior vena cava (PLSVC) with an absent right superior vena cava (RSVC) is a rare anatomic variation (0.07-0.13%) (1) that is typically asymptomatic and discovered incidentally during device implantation. Serious complications, including PLSVC-like shock, cardiac arrest or angina, can occur during catheterisation, which is likely due to the manipulation of the catheter in the coronary sinus or the perforation of the brachiocephalic vein, which can occur in the absence of the RSVC (2). This report presents a patient with PLSVC and an absent RSVC with no other cardiac abnormalities, who was diagnosed incidentally during pacemaker implantation (PMI). A 65-year-old male patient with hypertension was referred to our clinic for pacemaker implantation. The patient had suffered from vertigo with several presyncopal episodes. A 24-hour Holter revealed a 2:1 second-degree atrioventricular block with an intermittent third-degree atrioventricular block. These results prompted pacemaker implantation. The guidewire did not advance to the RSVC after routine puncture of the left axillary vein. Instead, an acute downward angula- tion was performed on the left side, parallel to the right-sided vena cava. A venogram was performed, and the diagnosis of PLSVC with an RSVC that descended into the coronary sinus (CS) was confirmed (Fig. 1A-D). Two 60-cm leads (Setrox S 60-B active fixation, Biotronik GmbH & Co., Berlin, Germany) were advanced separately in the right