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Left bundle branch area pacing (LBBAP) has emerged as an alternative to biventricular pacing (BVP) for cardiac resynchronization therapy (CRT). We aimed to compare the morbidity and mortality associated with LBBAP versus BVP in patients undergoing CRT implantation.Consecutive patients who received CRT from two high-volume implantation centers were retrospectively recruited. The primary endpoint was a composite of all-cause death and heart failure hospitalization, and the secondary endpoint was all-cause death.A total of 491 patients receiving CRT (154 via LBBAP and 337 via BVP) were included, with a median follow-up of 31 months. The primary endpoint was reached by 21 (13.6%) patients in the LBBAP group, as compared with 74 (22.0%) patients in the BVP group [hazard ratio (HR) 0.70, 95% confidence interval (CI) 0.43-1.14, P = 0.15]. There were 10 (6.5%) deaths in the LBBAP group, as compared with 31 (9.2%) in the BVP group (HR 0.91, 95% CI 0.44-1.86, P = 0.79). No significant difference was observed in the risk of either the primary or secondary endpoint between LBBAP and BVP after multivariate Cox regression (HR 0.74, 95% CI 0.45-1.23, P = 0.24, and HR 0.77, 95% CI 0.36-1.67, P = 0.51, respectively) or propensity score matching (HR 0.72, 95% CI 0.41-1.29, P = 0.28, and HR 0.69, 95% CI 0.29-1.65, P = 0.40, respectively).LBBAP was associated with a comparable effect on morbidity and mortality relative to BVP in patients with indications for CRT.

Background: Left bundle branch pacing (LBBP) has emerged as an alternative to biventricular pacing (BVP) for delivering cardiac resynchronization therapy. We sought to compare the acute improvement of electrical and mechanical synchrony, and hemodynamics between LBBP and BVP in patients with heart failure and left bundle branch block. Methods: LBBP and BVP were performed and compared in a crossover fashion in patients with heart failure and left bundle branch block undergoing cardiac resynchronization therapy implantation. Electrical synchrony was assessed by QRS duration and area, mechanical synchrony by the SD of time to peak velocity of 12 left ventricular segments (Ts-SD) and interventricular mechanical delay, and hemodynamics by the maximum rate of left ventricular pressure rise (dP/dt max ). Results: Twenty-one patient with heart failure and left bundle branch block (mean age 67±10 years, 48% male, and 90% nonischemic cause) were included. Both LBBP and BVP provided significant improvements in electrical and mechanical synchrony, and hemodynamics compared to the baseline. Compared with BVP, LBBP achieved a larger reduction in QRS duration (−11 ms [95% CI, −17 to −4 ms]; P =0.003) and QRS area (−85 µVs [95% CI, −113 to −56 µVs]; P P =0.001), with no significant difference in interventricular mechanical delay (−2 ms [95% CI, −13 to 8 ms]; P =0.63). The increase in dP/dt max from LBBP was significantly higher than that from BVP (6% [95% CI, 2%–9%]; P =0.002). Conclusions: LBBP delivers greater acute electrical and mechanical resynchronization and hemodynamic improvement than BVP in predominantly nonischemic heart failure patients with left bundle branch block. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04505384.

Aims The purpose of our study was to evaluate the feasibility and efficacy of cardiac resynchronization therapy (CRT) via left bundle branch pacing (LBBP-CRT) compared with optimized biventricular pacing (BVP) with adaptive algorithm (BVP-aCRT) in heart failure with reduced left ventricular ejection fraction ≤35% (HFrEF) and left bundle branch block (LBBB). Methods and results One hundred patients with HFrEF and LBBB undergoing CRT were prospectively enrolled in a non-randomized fashion and divided into two groups (LBBP-CRT, n = 49; BVP-aCRT, n = 51) in four centres. Implant characteristics and echocardiographic parameters were accessed at baseline and during 6-month and 1-year follow-up. The success rate for LBBP-CRT and BVP-aCRT was 98.00% and 91.07%. Fused LBBP had the greatest reduced QRS duration compared to BVP-aCRT (126.54 ± 11.67 vs. 102.61 ± 9.66 ms, P Conclusions The feasibility and efficacy of LBBP-CRT demonstrated better electromechanical resynchronization and higher clinical and echocardiographic response, especially higher super-response than BVP-aCRT in HFrEF with LBBB.

Background Leadless pacemaker has been acknowledged as a promising pacing strategy to prevent pocket and lead-related complications. Although rare, cardiac perforation remains a major safety concern for implantation of Micra transcatheter pacing system (TPS). Case presentation A 83-year-old female with low body mass index (18.9 kg m−2) on dual anti-platelet therapy, was indicated for Micra TPS implantation due to sinus arrest and paroxysmal atrial flutter. The patient developed mild pericardial effusion during the procedure since the delivery catheter was accidentally placed into the coronary sinus for several times. Cardiac perforation with moderate pericardial effusion and pericardial tamponade was detected 2 h post-procedure. The patient was treated with immediately pericardiocentesis and recovered without further invasive therapy. Conclusion Pericardial effusion caused by accidently placing a delivery catheter into the coronary sinus is rare but should be carefully considered in Micra TPS implantation, especially for those with periprocedural anti-platelet therapy.

To compare electromechanical ventricular synchrony when pacing from different sites, including right ventricular apex pacing (RVAP), right ventricular septum pacing (RVSP), His bundle pacing (HBP), left bundle branch pacing (LBBP), and RVSP during unipolar pacing from the ring electrode of LBBP lead (RVSPTwenty patients with complete atrioventricular block indicated for dual-chamber pacemaker implantation were included in the study. Unipolar pacing at different sites, including RVAP, RVSP, HBP, LBBP, and RVSPSimilar to HBP (114.84 ± 18.67 ms), narrower paced QRSd was found in LBBP (116.15 ± 11.60 ms) as compared to RVSPHis-Purkinje conduction system pacing (HPCSP) achieved better electrical and mechanical synchrony than conventional RV pacing. For interventricular synchrony, only LBBP initiated earlier LV activation than RV, in accordance with the right bundle branch block (RBBB) pattern of paced QRS during LBBP. Sti-LVAT might be a good parameter correlating with LV systolic function and mechanical synchrony.

Background Cardiac resynchronization therapy (CRT)-defibrillator (CRT-D) has been more widely implanted than CRT-pacemaker (CRT-P) in patients of heart failure with reduced ejection fraction and prolonged QRS duration. However, the superiority of CRT-D over CRT-P in improving prognosis has not been well established. Methods Consecutive patients who underwent CRT implantation between 2005 and 2016 were retrospectively recruited and followed up to December 2017. Baseline characteristics were collected and all-cause mortality was compared between CRT-D and CRT-P recipients. Propensity score matched analysis was further performed to validate the results. Results A total of 345 patients (219 CRT-D, 126 CRT-P) were included. During a median follow-up of 36 months, there were 81 deaths (37.0%) in the CRT-D group compared to 56 deaths (44.4%) in the CRT-P group. There was no significant difference in the risk of mortality between CRT-D and CRT-P groups [hazard ratio (HR) 0.99, 95% CI 0.70–1.40, p = 0.95]. Propensity score matching yielded 111 cases per group, and there was no significant difference in the risk of mortality between CRT-D and CRT-P groups (HR 0.87, 95%CI 0.57–1.34, p = 0.53). No significant difference between CRT-D and CRT-P in reducing mortality was observed in any pre-specified subgroups, although the difference between CRT-D and CRT-P was more pronounced in patients with left bundle branch block (p = 0.01 for interaction). Conclusions CRT-D did not reduce all-cause mortality compared with CRT-P in this retrospective propensity score matched study. A comprehensive score system incorporating multiple factors is needed for risk stratification and guidance on device selection.

Monitoring of lead depth is crucial to achieve left bundle branch pacing (LBBP) with a low capture threshold and avoid septal perforation, but lacks informative approach.We aimed to prospectively assess the predictive value of current of injury on the occurrence of inadequate left bundle branch (LBB) capture threshold and acute septal perforation.Consecutive patients who received LBBP were enrolled. ST-segment elevation ≥ 25% of intrinsic R-wave amplitude on the unipolar intracardiac electrogram was defined as a sign of distinct current of injury. An LBB capture threshold of1.5 V/0.5 ms was considered acceptable.LBBP was attempted 513 times in 212 patients. The LBB capture threshold was more likely to improve to an acceptable level after 10 minutes in leads with initial (33 of 47 vs 0 of 8, with vs without) and residual (29 of 33 vs 4 of 14, with vs without) current of injury recorded on the tip electrode (P.0001). Lead perforation during the procedure has occurred in 11 patients who had no current of injury noted on the tip electrode. The ratio of current of injury recorded on the tip electrode to that on the ring electrode was correlated to the lead depth determined by sheath angiography (Spearman correlation coefficient -0.624; P.0001), and microperforation is highly possible when the ratio is decreased to1 (sensitivity 100%; specificity 96.6%).Current of injury is a useful tool in forecasting LBBP lead depth and septal perforation, and it could facilitate the decision-making process when the initial LBB capture threshold is undesirable.

INTRODUCTION Several automatic algorithms have developed to optimize the timing cycle setting in cardiac resynchronization therapy (CRT). The present study aims to investigate whether the novel device-based SyncAV algorithm could elicit better synchrony and acute hemodynamic response. METHODS AND RESULTS Thirty five patients undergoing CRT implantation were prospectively studied. The device was programmed to three biventricular (BiV) pacing modes sequentially after the procedure: QuickOpt algorithm (mode I), SyncAV algorithm with default 50 ms offset (mode II), and SyncAV algorithm with optimized offset minimizing QRS duration (QRSd) (mode III). After each setting, electrocardiographic and echocardiographic data were collected. As a result, QRSd was reduced from 172.8 ± 17.9 ms during intrinsic conduction to 153.1 ± 15.9 ms in mode I, further narrowed to 140.5 ± 16.7 ms in mode II, and reached shortest (134.8 ± 16.1 ms) in mode III (P .05). Mode I presented significantly higher aortic velocity time integral than intrinsic conduction (21.0 ± 6.4 cm vs 18.4 ± 5.5 cm; P

INTRODUCTION Left bundle branch area pacing (LBBAP) has recently been reported to be a new physiological pacing strategy with clinical feasibility and safety. The present study aims to investigate depolarization-repolarization measures including QT interval, QT dispersion (QTD), and Tpeak-end interval (Tp Te ) in this novel LBBAP strategy. METHODS AND RESULTS A total of 131 pacing-indicated patients were prospectively enrolled and randomized to the LBBAP group (n = 66) and right ventricular septum pacing (RVSP) group (n = 65). LBBAP was successfully achieved in 61 subjects with stable lead performance and comparable complications (ie, pocket hematoma, lead perforation, and dislodgement) compared with RVSP. Of the 61 patients with successful LBBAP, the mean LV peak activation time was 67.89 ± 6.80 ms, with the LBB potential mapped in 46 cases (75.4%). Electrocardiogram (ECG) indices were compared between these two groups before and after implantation. As a result, LBBAP yielded a narrower paced QRS duration (121.49 ± 9.87 ms vs 145.62 ± 8.89 ms; P

The mechanism of cardiac resynchronization therapy (CRT) remains unclear. In this study, mitochondria calcium uniporter (MCU), dynamin‐related protein‐1 (DNM1L/Drp1) and their relationship with autophagy in heart failure (HF) and CRT are investigated. Thirteen male beagle's dogs were divided into three groups (sham, HF, CRT). Animals received left bundle branch (LBB) ablation followed by either 8‐week rapid atrial pacing or 4‐week rapid atrial pacing and 4‐week biventricular pacing. Cardiac function was evaluated by echocardiography. Differentially expressed genes (DEGs) were detected by microarray analysis. General morphological changes, mitochondrial ultrastructure, autophagosomes and mitophagosomes were investigated. The cardiomyocyte stretching was adopted to imitate the mechanical effect of CRT. Cells were divided into three groups (control, angiotensin‐II and angiotensin‐II + stretching). MCU, DNM1L/Drp1 and autophagy markers were detected by western blots or immunofluorescence. In the present study, CRT could correct cardiac dysfunction, decrease cardiomyocyte's size, alleviate cardiac fibrosis, promote the formation of autophagosome and mitigate mitochondrial injury. CRT significantly influenced gene expression profile, especially down‐regulating MCU and up‐regulating DNM1L/Drp1. Cell stretching reversed the angiotensin‐II induced changes of MCU and DNM1L/Drp1 and partly restored autophagy. CRT's mechanical effects down‐regulated MCU, up‐regulated DNM1L/Drp1 and subsequently enhanced autophagy. Besides, the mechanical stretching prevented the angiotensin‐II‐induced cellular enlargement.

Background HF incurs high disease burden, and the effectiveness of known HF treatments is unsatisfactory. Therefore, seeking novel therapeutic target of HF is important. The present study aimed to investigate the role of the mitochondrial calcium uniporter (MCU) and its relationship with autophagy in overload-induced heart failure (HF). Methods and results In both early-stage and end-stage of pressure overload-induced HF, MCU appeared up-regulated along with heart enlargement, increased microtubule-associated proteins 1A/1B light chain 3B (LC3B) II/I ratio and autophagosome content, damaged cardiac function, and ventricular asynchrony. However, sequestosome-1 (SQSTM1/p62) level decreased indicating blockaded autophagic flux. Seven-week administration of MCU inhibitor ruthenium red improved cardiac function and mitigated its pathological change. MCU inhibition maintained mitochondrial integrity, increased LC3B II/I ratio, up-regulated Parkin and Pink1, and down-regulated SQSTM1/p62. MCU inhibition also alleviated ventricular asynchrony of HF, and this might be related to connexin-43 up-regulation. In vitro study validated intervention on MCU leading to elevation of autophagy and mitophagy. MCU inhibition could partly prevent from excessive cellular enlargement induced by isoprenaline. Conclusions In summary, MCU inhibition played an important role in pressure overload-induced heart failure through autophagy and mitophagy enhancement, and intervention on MCU offered cardioprotective effects. To our knowledge, the role of MCU in HF and its relationship with autophagy and mitophagy are firstly disclosed. Moreover, our study suggests that MCU inhibition could be explored as a novel therapeutic concept in HF.

Background It is unclear whether clinical benefits of cardiac resynchronization can be achieved by pacing only the left ventricle. Hypothesis We aimed to compare the effect of a novel adaptive left ventricular-only fusion pacing (LVP) on ventricular function with conventional biventricular pacing (BVP) in cardiac resynchronization therapy (CRT) indicated patients. Methods This prospective, randomized, multicenter study enrolled CRT-indicated patients with PR interval ≤ 200 ms who were randomized in the adaptive LVP group (using the AdaptivCRT™ algorithm with intentional non-capture right ventricular pacing) or the echocardiography-optimized BVP group. Cardiac function and echocardiography were evaluated at baseline and follow-ups. CRT super response was defined as two-fold or more increase of left ventricular ejection fraction (LVEF) or final LVEF >45%, and LV end-systolic volume (LVESV) decrease >15%, and New York Heart Association (NYHA) class improved by at least one level. Results Sixty-three patients were enrolled in the study (LVP = 34 vs. BVP = 29). At 6-month follow-up, significant improvements in LVEF, LVESV, and NYHA class were observed in both groups. The CRT super response rate was significantly higher in patients with high-percentage adaptive LV-only pacing in LVP group (68.4%) than in BVP group (36.4%, p = .04). Conclusions Adaptive LV-only pacing was comparable to BVP in improving cardiac function and clinical condition in CRT-indicated patients. This finding raises the possibility that an adaptive LVP algorithm with appropriate right ventricular sensing to fuse with intrinsic right ventricular activation in a two-lead (right atrium and left ventricle) device may provide clinical benefit in a subset of CRT patients with intact atrioventricular conduction.

Background: Although left bundle branch pacing (LBBP) has emerged as a novel physiological pacing strategy with a low and stable threshold, its safety has not been well-documented. In the present study, we included all the patients with procedure-related complications at our centre to estimate these LBBP cases with unique complications.Methods: We enrolled 612 consecutive patients who received the procedure in Zhongshan Hospital, Fudan University, between January 2018 and July 2020. Regular follow-ups were conducted (at 1, 3, and 6 months in the first year and every 6–12 months from the second year), and the clinical data of the patients with complications were collected and analyzed.Results: With a mean follow-up period of 12.32 ± 5.21 months, procedure-related complications were observed in 10 patients (1.63%) that included two postoperative septum perforations (2/612, 0.33%), two postoperative lead dislodgements (2/612, 0.33%), four intraoperative septum injuries (4/612, 0.65%), and two intraoperative lead fractures (2/612, 0.33%). Pacing parameters were stable during follow-up, and no major complications were observed after lead repositioning in the cases of septum perforation and lead dislodgement.Conclusion: The incidence of procedure-related complications for LBBP, namely postoperative septum perforation, postoperative lead dislodgement, intraoperative septum injury, and intraoperative lead fracture, were low. No adverse clinical outcomes were demonstrated after successful repositioning of the lead and appropriate treatment.

Nearly one third of patients receiving cardiac resynchronization therapy (CRT) suffer non-response. We intend to develop predictive models using machine learning (ML) approaches and easily attainable features before CRT implantation.The baseline characteristics of 752 CRT recipients from two hospitals were retrospectively collected. Nine ML predictive models were established, including logistic regression (LR), elastic network (EN), lasso regression (Lasso), ridge regression (Ridge), neural network (NN), support vector machine (SVM), random forest (RF), XGBoost and k-nearest neighbour (k-NN). Sensitivity, specificity, precision, accuracy, F1, log-loss, area under the receiver operating characteristic (AU-ROC), and average precision (AP) of each model were evaluated. AU-ROC was compared between models and the latest guidelines. Six models had an AU-ROC value above 0.75. The LR, EN and Ridge models showed the highest overall predictive power compared with other models with AU-ROC at 0.77. The XGBoost model reached the highest sensitivity at 0.72, while the highest specificity was achieved by Ridge model at 0.92. All ML models achieved higher AU-ROCs that those derived from the latest guidelines (all P 0.05). The effect size analysis identified left bundle branch block, left ventricular end-systolic diameter, and history of percutaneous coronary intervention as the most crucial predictors of CRT response. An online tool to facilitate the prediction of CRT response is freely available at http://www.crt-response.com/.ML algorithms produced efficient predictive models for evaluation of CRT response with features before implantation. Tools developed accordingly could improve the selection of CRT candidates and reduce the incidence of non-response.

Aims The aim of this study is to prospectively assess the feasibility and safety of left bundle branch pacing (LBBP) when compared with right ventricular pacing (RVP) during mid-long-term follow-up in a large cohort. Methods and results Patients (n = 554) indicated for pacemaker implantation were prospectively and consecutively enrolled and were non-randomized divided into LBBP group and RVP group. The levels of cTnT and N-terminal pro-B type natriuretic peptide were measured and compared within 2 days post-procedure between two groups. Implant characteristics, procedure-related complications, and clinical outcomes were also compared. Pacing thresholds, sensing, and impedance were assessed during procedure and follow-up. Left bundle branch pacing was feasible with a success rate of 94.8% with high incidence of LBB potential (89.9%), selective LBBP (57.8%), and left deviation of paced QRS axis (79.7%) with mean Sti-LVAT of 65.07 ± 8.58 ms. Paced QRS duration was significantly narrower in LBBP when compared with RVP (132.02 ± 7.93 vs. 177.68 ± 15.58 ms, P Conclusion Left bundle branch pacing was feasible in bradycardia patients associated with stable pacing parameters during 18 months follow-up. Paced QRS duration was significantly narrower than that of RVP. Though cTnT elevation was more significant in LBBP within 2 days post-procedure, the complications, and cardiac outcomes were not significantly different between two groups.

Background Heart failure is associated with ventricular dyssynchrony and energetic inefficiency, which can be alleviated by cardiac resynchronization therapy (CRT) with approximately one-third of non-response rate. Thus far, there is no specific biomarker to predict the response to CRT in patients with heart failure. In this study, we assessed the role of the blood metabolomic profile in predicting the response to CRT. Methods A total of 105 dilated cardiomyopathy patients with severe heart failure who received CRT were included in our two-stage study. Baseline blood samples were collected prior to CRT implantation. The response to CRT was defined according to echocardiographic criteria. Metabolomic profiling of serum samples was carried out using ultrahigh performance liquid chromatography coupled with quadrupole-time-of-flight mass spectrometry. Results Seventeen metabolites showed significant differences in their levels between responders and non-responders, and these metabolites were primarily involved in six pathways, including linoleic acid metabolism, Valine, leucine and isoleucine biosynthesis, phenylalanine metabolism, citrate cycle, tryptophan metabolism, and sphingolipid metabolism. A combination of isoleucine, tryptophan, and linoleic acid was identified as an ideal metabolite panel to distinguish responders from non-responders in the discovery set (n = 51 with an AUC of 0.981), and it was confirmed in the validation set (n = 54 with an AUC of 0.929). Conclusions Mass spectrometry based serum metabolomics approach provided larger coverage of metabolome which can help distinguish CRT responders from non-responders. A combination of isoleucine, tryptophan, and linoleic acid may associate with significant prognostic values for CRT.

Cardiac resynchronization therapy (CRT) is well acknowledged as an effective treatment for dyssynchronous heart failure. However, the molecular mechanism is unclear to date. Mitochondrial dysfunction and impaired energetic metabolism are two important mechanisms that lead to heart failure. Therefore, we aim to screen the changes of mitochondria-associated proteins and signaling pathways involved in heart failure and CRT treatment. A total of 24 beagle dogs were randomly assigned into control (CON), heart failure (HF), or CRT group. Myocardial mitochondria from the free wall of left ventricle was extracted for isobaric tags for relative and absolute quantitation (iTRAQ) labeling coupled with two-dimensional liquid chromatography tandem mass spectrometry analysis (2DLC-MS/MS). A total of 2190 proteins were identified, among which 234 proteins were differentially expressed in HF compared with CON group, 151 proteins were differentially expressed in CRT compared with HF group. A total of 192 of the 234 differentially expressed proteins in HF group were changed oppositely by CRT treatment, and 128 of the 151 CRT-induced differentially expressed proteins showed opposite trend of expression to HF/CON. Gene Ontology analysis of the 128 proteins revealed that 16 were localized in mitochondria, 17 were associated with calcium signaling, and 7 could be secreted extracellularly for cell-to-cell signaling. Calpain-1 (CAPN1), which is localized to mitochondria and related to calcium signaling, was upregulated in HF and downregulated after CRT treatment. CRT treatment also improved mitochondrial morphology and function and reduced collagen areas of both interstitial and perivascular fibrosis. CRT treatment significantly improved cardiac function, reduced myocardial fibrosis, and enhanced mitochondrial function in the failing heart through CAPN1 downregulation.

To date, several techniques for transseptal left ventricular (LV) endocardial pacing for cardiac resynchronization therapy (CRT) have been proposed in patients for whom routine transvenous LV pacing is infeasible. These techniques are of varying difficulty and complexity, and some requires devices not easily accessible. We herein report a simple, safe and effective approach of atrial transseptal LV lead implantation using arteriovenous loop technique in a patient for whom transvenous LV implantation lead had failed.

Background Abnormal cardiac repolarization is closely associated with ventricular tachycardia/ventricular fibrillation (VT/VF). Myocardial ischemia and infarction aggravate cardiac repolarization dispersion, and VT/VF could be lethal in the early stage of ST-segment elevation myocardial infarction (STEMI). Unfortunately, VT/VF cannot be effectively predicted in current clinical practice. The present study aimed to assess electrocardiographic parameters of the sinus rhythmic complex in relation to cardiac repolarization, e.g., QT interval and T-peak to T-end interval (TpTe), to independently predict VT/VF in acute STEMI. Additionally, we hypothesized that QT and TpTe of PVC would be also valuable to predict VT/VF in STEMI. Methods and results A total of 198 cases diagnosed as STEMI with PVC on admission by electrography were included. During hospitalization, VT/VF values were recorded. Logistic analysis was performed between patients with and without VT/VF to validate independent electrocardiographic predictors. QTcPVC interval > 520 ms (OR = 3.2; P = 0.027), TpTe interval > 100 ms (OR = 3.1; P = 0.04), TpTePVC > 101 ms (OR = 3.6; P = 0.029), TpTe/QT > 0.258 (OR = 5.7; P = 0.003), and TpTe/QTPVC > 0.253 (OR = 3; P = 0.048). However, QRS duration, QTc interval, coupling interval, and QRSPVC duration did not predict VT/VF. Besides, QRSPVC duration >140 ms (OR = 2.6; P = 0.001) independently predicted LVEF decrease after 1 year or more. Conclusions QTcPVC interval, TpTe interval, TpTePVC interval, TpTe/QT ratio, and TpTe/QTPVC ratio are risk factors for ECG independent from other confounding factors in predicting VT/VF in the acute phase of STEMI. In addition, PVC characteristics as risk factors for VT/VF in acute phase and LVEF decrease in chronic phase were firstly reported.

Interatrial septum (IAS) pacing seems to be a promising strategy for the prevention of atrial fibrillation (AF); however, studies have yielded conflicting results. This meta-analysis was to compare IAS with right atrial appendage (RAA) pacing on the prevention of postpacing AF occurrence. Pubmed, MEDLINE, EMBASE and Web of Science databases were searched through October 2016 for randomized controlled trials comparing IAS with RAA pacing on the prevention of AF. Data concerning study design, patient characteristics and outcomes were extracted. Risk ratio (RR), weighted mean differences (WMD) or standardized mean differences (SMD) were calculated using fixed or random effects models. A total of 12 trials involving 1146 patients with dual-chamber pacing were included. Although IAS was superior to RAA pacing in terms of reducing the number of AF episodes (SMD = −0.29, P = 0.05), AF burden (SMD = −0.41, P = 0.008) and P -wave duration (WMD = −34.45 ms, P < 0.0001), neither permanent AF occurrence (RR = 0.94, P = 0.58) nor recurrences of AF (RR = 0.88, P = 0.36) were reduced by IAS pacing. Nevertheless, no differences were observed concerning all-cause death (RR = 1.04, P = 0.88), procedure-related events (RR = 1.17, P = 0.69) and pacing parameters between IAS and RAA pacing in the follow-up period. IAS pacing is safe and as well tolerated as RAA pacing. Although IAS pacing may fail to prevent permanent AF occurrence and recurrences of AF, it is able to not only improve interatrial conduction, but also reduce AF burden.

Introduction Hemodialysis (HD) patients are under observably elevated cardiovascular mortality. Cardiac dysfunction is closely related to death caused by cardiovascular diseases (CVD). In the general population, repetitive myocardial ischemia induced left ventricular (LV) dysfunction may progress to irreversible loss of contraction step by step, and finally lead to cardiac death. In HD patients, to remove water and solute accumulated from 48 or 72 hours of interdialysis period in a 4-hour HD session will induce myocardial ischemia. In this study, we evaluated the prevalence and potential risk factors associated with HD-induced LV systolic dysfunction and provide some evidences for clinical strategies. Methods We recruited 31 standard HD patients for this study from Fudan University Zhongshan hospital. Echocardiography was performed predialysis, at peak stress during HD (15 minutes prior to the end of dialysis), and 30 minutes after HD. Auto functional imaging (AFI) was used to assess the incidence and persistence of HD-induced regional wall motion abnormalities (RWMAs). Blood samples were drawn to measure biochemical variables. Findings Among totally 527 segments of 31 patients, 93.54% (29/31) patients and 51.40% (276/527) segments were diagnosed as RWMAs. Higher cTnT (0.060 ± 0.030 vs. 0.048 ± 0.015 ng/mL, P = 0.023), phosphate (2.07 ± 0.50 vs. 1.49 ± 0.96 mmol/L, P = 0.001), UFR (11.00 ± 3.89 vs. 8.30 ± 2.66 mL/Kg/h, P = 0.039) and lower albumin (37.83 ± 4.48 vs. 38.38 ± 2.53 g/L, P = 0.050) were found in patients with severe RWMAs (RWMAs in more than 50% segments). After univariate and multivariate analysis, interdialytic weight gain (IDWG) was found as independent risk factor of severe RWMAs (OR = 1.047, 95%CI 1.155-4.732, P = 0.038). Discussion LV systolic dysfunction induced by HD is prevalent in conventional HD patients and should be paid attention to. Patients would benefit from better weight control during interdialytic period to reduce ultrafiltration rate.

BACKGROUND The consequence of cessation of biventricular pacing in super-responders of cardiac resynchronization therapy (CRT) has not been fully investigated. METHODS In this prospective, single-blinded clinical trial, 21 super-responders were randomly assigned to the ceased pacing (CeP, 11 patients) group or the continued pacing (CoP, 10 patients) group. Patients randomized to the CeP group underwent cessation of biventricular pacing. New York Heart Association (NYHA) class, quality of life (QOL) assessed with Minnesota questionnaire, 6-minute walking distance (6MWD), left ventricular end systolic volume (LVESV), left ventricular end-diastolic volume (LVEDV), and left ventricular ejection fraction (LVEF) were compared between groups at 3- and 6-month follow-up. RESULTS No significant difference was observed between the CeP and CoP groups regarding NYHA class, QOL, 6MWD, LVESV, LVEDV, or LVEF after 3 months (all P > 0.05). After 6 months, there existed no significant difference between the CeP and CoP groups with regard to NYHA class, QOL, 6MWD, LVESV, and LVEDV (all P > 0.05); however, LVEF was significantly lower in the CeP group than that of the CoP group (0.49 ± 0.10 vs 0.60 ± 0.11, P = 0.04), and LVEF was significantly reduced in the CeP group compared with the baseline value at randomization (0.49 ± 0.10 vs 0.54 ± 0.06, P = 0.04). CONCLUSION LVEF was significantly reduced in super-responders of CRT 6 months after cessation of pacing. Super-responders to CRT should receive continued, long-term pacing to preserve recovered LV function.

Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) has been shown to play an important role in cardiac remodeling under different pathologic conditions. The role of genetic polymorphisms in the LOX1 gene, however, remains unclear in the development of left ventricular hypertrophy (LVH) for patients with hypertension.A total of 536 patients diagnosed with essential hypertension (EH) were recruited in this study. Patients were assigned to the LVH+ (n=143) and LVH- (n=393) groups, respectively. The serum LOX1 level was measured and three single nucleotide polymorphisms (SNPs), i.e. intron 4 (G→A), intron 5(T→G), and 3' UTR (T→C) of the LOX1 gene were genotyped.The genotype frequencies of intron 4 GA and 3'UTR TC were not significantly different between the LVH+ and LVH- groups (both P0.05), however, frequencies of 501GC were significantly different between those two groups (P=0.007). The 501CC genotype carriers had a markedly higher serum LOX1 level and an increased risk to develop LVH (adjusted OR=2.444, adjusted P=0.002). There was a positive correlation between serum LOX1 level and left ventricular mass index (r=0.907, P0.001); a cutoff value of 1.0 ng/mL for sLOX-1 was applied to significantly differentiate the LVH+ patients from the LVH- patients with 84% sensitivity and 86% specificity.Our data suggest that both the 501C SNP in the LOX1 gene and the serum LOX1 level may be used to predict the development of LVH among EH patients.

Background: The aim is to study the feasibility and efficacy of His-Purkinje conduction system pacing (HPCSP) in cardiac resynchronization therapy (CRT) candidates of chronic heart failure with permanent atrial fibrillation (AF). Subjects and Methods: Patients with chronic heart failure and permanent AF (n = 16) were enrolled from the Department of Cardiology, Zhongshan Hospital of Fudan University, from September 2017 to April 2019 in this observational case study. The patients with chronic heart failure (left ventricular ejection fraction [LVEF] 120 ms. HPCSP lead connected to the RA port of the generator was implanted together with conventional biventricular pacing (BVP) and was programmed as HPCSP postprocedure. QRS durations were measured and compared during intrinsic, BVP, and HPCSP. Pacing parameters were measured and compared during postimplantation immediately and 6 months postimplantation. Echocardiogram parameters, New York Heart Association (NYHA) class, and 6-min walking distance (6MWD) were collected and compared between baseline and 6 months postimplantation. Results: QRS durations were significantly different during HPCSP compared with BVP (P < 0.0001). Pacing parameters including threshold and R wave amplitude were not significantly different during postimplantation immediately and 6 months postimplantation, whereas impedance was significantly different (P = 0.028). LVEF, left atrial diameter, left ventricular end-diastolic diameter, left ventricular end-systolic diameter, mitral regurgitation, tricuspid annular plane systolic excursion, pulmonary artery systolic pressure, and the percentages of moderate-to-severe mitral regurgitation and tricuspid regurgitation were not significantly different between baseline and 6 months postimplantation, whereas NYHA class and 6MWD were significantly different (P < 0.0001). Conclusion: HPCSP was feasible and effective in CRT candidates of chronic heart failure with permanent AF and low ventricular rate. It could significantly reduce QRS duration as compared to BVP. Moreover, although LVEF was not obviously improved, the pacing parameters were stable and NYHA class and 6MWD were improved during HPCSP at 6-month follow-up.

Introduction Hemodialysis (HD) patients are under observably elevated cardiovascular mortality. Cardiac dysfunction is closely related to death caused by cardiovascular diseases (CVD). In the general population, repetitive myocardial ischemia induced left ventricular (LV) dysfunction may progress to irreversible loss of contraction step by step, and finally lead to cardiac death. In HD patients, to remove water and solute accumulated from 48 or 72 hours of interdialysis period in a 4-hour HD session will induce myocardial ischemia. In this study, we evaluated the prevalence and potential risk factors associated with HD-induced LV systolic dysfunction and provide some evidences for clinical strategies. Methods We recruited 31 standard HD patients for this study from Fudan University Zhongshan hospital. Echocardiography was performed predialysis, at peak stress during HD (15 minutes prior to the end of dialysis), and 30 minutes after HD. Auto functional imaging (AFI) was used to assess the incidence and persistence of HD-induced regional wall motion abnormalities (RWMAs). Blood samples were drawn to measure biochemical variables. Findings Among totally 527 segments of 31 patients, 93.54% (29/31) patients and 51.40% (276/527) segments were diagnosed as RWMAs. Higher cTnT (0.060 ± 0.030 vs. 0.048 ± 0.015 ng/mL, P = 0.023), phosphate (2.07 ± 0.50 vs. 1.49 ± 0.96 mmol/L, P = 0.001), UFR (11.00 ± 3.89 vs. 8.30 ± 2.66 mL/Kg/h, P = 0.039) and lower albumin (37.83 ± 4.48 vs. 38.38 ± 2.53 g/L, P = 0.050) were found in patients with severe RWMAs (RWMAs in more than 50% segments). After univariate and multivariate analysis, interdialytic weight gain (IDWG) was found as independent risk factor of severe RWMAs (OR = 1.047, 95%CI 1.155-4.732, P = 0.038). Discussion LV systolic dysfunction induced by HD is prevalent in conventional HD patients and should be paid attention to. Patients would benefit from better weight control during interdialytic period to reduce ultrafiltration rate.

Cardiac resynchronization therapy (CRT) has been mostly achieved by biventricular pacing (BVP) in patients with chronic heart failure (CHF), although it can also be provided by left ventricular pacing (LVP). The superiority of BVP over LVP remains uncertain. The present meta-analysis of randomized controlled trials was performed to compare the effects of LVP to BVP in patients with CHF. Outcomes analyzed included clinical status (6-minute walk distance, peak oxygen consumption, quality of life, New York Heart Association class), LV function (LV ejection fraction), and LV remodeling (LV end-systolic volume). Five trials fulfilled criteria for inclusion in analysis, which included 574 patients with CHF indicated for CRT. After a midterm follow-up, pooled analysis demonstrated that LVP resulted in similar improvements in 6-minute walk distance (weighted mean difference [WMD] 11.25, 95% confidence interval [CI] -12.39 to 34.90, p = 0.35), quality of life (WMD 0.34, 95% CI -3.72 to 4.39, p = 0.87), peak oxygen consumption (WMD 1.00, 95% CI -0.84 to 2.85, p = 0.29), and New York Heart Association class (WMD -0.19, 95% CI -0.79 to 0.42, p = 0.54). There was a trend toward a superiority of BVP over LVP for LV ejection fraction (WMD 1.28, 95% CI -0.11 to 2.68, p = 0.07) and LV end-systolic volume (WMD -5.73, 95% CI -11.86 to 0.39, p = 0.07). In conclusion, LVP achieves similar improvement in clinical status as BVP in patients with CHF, whereas there was a trend toward superiority of BVP over LVP for LV reverse modeling and systolic function.

Cardiac resynchronisation therapy (CRT)-defibrillator (CRT-D) has been widely used over CRT-pacemaker (CRT-P) in patients of heart failure with reduced ejection fraction (HFrEF) and prolong QRS duration. However, the superiority of CRT-D over CRT-P to reduce mortality has not been systematically

The consequences of cessation of biventricular pacing in super-responders of cardiac resynchronization therapy (CRT) has not been fully investigated. Super-responders were identified and randomized to ceased pacing (CeP) and continuous pacing (CoP) groups. Patients randomized to CeP group underwent

Background Sudden cardiac death is one of the primary causes of mortality in chronic hemodialysis (HD) patients. Prolonged QTc interval is associated with increased rate of sudden cardiac death. The aim of this article is to assess the abnormalities found in electrocardiograms (ECGs), and to explore factors that can influence the QTc interval. Methods A total of 141 conventional HD patients were enrolled in this study. ECG tests were conducted on each patient before a single dialysis session and 15 minutes before the end of dialysis session (at peak stress). Echocardiography tests were conducted before dialysis session began. Blood samples were drawn by phlebotomy immediately before and after the dialysis session. Results Before dialysis, 93.62% of the patients were in sinus rhythm, and approximately 65% of the patients showed a prolonged QTc interval (i.e., a QTc interval above 440 ms in males and above 460ms in females). A comparison of ECG parameters before dialysis and at peak stress showed increases in heart rate (77.45±11.92 vs. 80.38±14.65 bpm, p = 0.001) and QTc interval (460.05±24.53 ms vs. 470.93±24.92 ms, p