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16,467 result(s) for "bundle"
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Immediate clinical outcomes of left bundle branch area pacing vs conventional right ventricular pacing
Background Left bundle branch area pacing (LBBaP) is a new physiological pacing strategy that produces comparable clinical effects to His bundle pacing (HBP). Objective The purpose of this study was to investigate the immediate clinical outcomes of LBBaP vs RVP. Methods and Results From April 2018 to September 2018, we included 44 patients under continuous pacemaker implantation. Patients were randomly divided into the LBBaP group and conventional RVP group. Compared to the RVP group, the LBBaP group displayed significantly increased operative (90.10 ± 19.68 minutes vs 61.57 ± 6.62 minutes, P < .001) and X‐ray exposure times (15.55 ± 5.62 minutes vs 4.67 ± 2.06 minutes, P < .001). The lead threshold of the LBBaP group was increased (0.68 ± 0.20 mV vs 0.51 ± 0.0 mV, P = .001), while the R‐wave amplitude and ventricular impedance did not significantly differ between the two groups. The conventional RVP procedure significantly widened the QRS complex (93.62 ± 8.28 ms vs 135.19 ± 12.21 ms, P = .001), whereas the LBBaP had no effect on QRS complex (130.13 ± 43.30 ms vs 112.63 ± 12.14 ms, P = .904). Furthermore, the LBBaP procedure significantly narrowed the QRS complex in patients with left bundle branch block (LBBB) (168.43 ± 38.870 ms vs 119.86 ± 6.69 ms, P = .019). Conclusion LBBaP is a new physiological, safe and effective pacing procedure with a high overall success rate. Compared to conventional RVP, LBBaP can correct LBBB, thereby improving cardiac electrical dyssynchrony.
Conduction system pacing vs biventricular resynchronization in heart failure with reduced ejection fraction and left bundle branch block: Rationale and design of the PhysioSync-HF Trial
•Conduction system pacing, also termed physiologic pacing, is a novel alternative to biventricular resynchronization that may improve left ventricular remodeling while minimizing costs.•PhysioSync-HF is an investigator-led, randomized, multicenter clinical trial comparing conduction system pacing and biventricular resynchronization on heart failure-related outcomes in 179 patients with heart failure with reduced ejection fraction and left bundle branch block.•Half of trial participants are women, and most are non-White, ensuring patient representativeness and generalizability. Cardiac resynchronization therapy reduces heart failure hospitalizations and mortality in patients with heart failure with reduced ejection fraction (HFrEF) and left bundle branch block (LBBB). Conduction system pacing, which directly activates the His-Purkinje system, has emerged as a safe alternative to traditional biventricular resynchronization that may offer clinical benefits at lower costs. The PhysioSync-HF trial is an investigator-led, randomized, multicenter clinical trial designed to assess whether conduction system pacing is noninferior to biventricular resynchronization on heart failure-related outcomes in patients with HFrEF and LBBB. The study population consists of 179 adults with symptomatic heart failure (New York Heart Association [NYHA] class II-III), left ventricular ejection fraction (LVEF) ≤35%, and LBBB (QRS ≥130 ms). Patients were randomized 1:1 to receive conduction system pacing or biventricular resynchronization and followed for 12 months postprocedure. The primary endpoint is a hierarchy of all-cause death, any hospitalization for heart failure, any urgent visit for heart failure, and change in LVEF from baseline. The key secondary endpoint is the mean total direct medical cost per patient. Additional endpoints include assessments of health-related quality of life, functional capacity, and safety. Enrollment began in November 2022 and concluded in December 2023. PhysioSync-HF will determine whether conduction system pacing is noninferior to biventricular resynchronization on heart failure-related outcomes in patients with HFrEF with LBBB. NCT05572736. *In selected sites. 6MWT indicates 6-minute walk test; CPET, cardiopulmonary exercise test; ECG, electrocardiogram; EQ-5D, EuroQol Group 5-Dimensions questionnaire; HF, heart failure; KCCQ, Kansas City Cardiomyopathy Questionnaire; LVEF, left ventricular ejection fraction. [Display omitted]
Chronic pacing and adverse outcomes after transcatheter aortic valve implantation
ObjectiveMany patients undergoing transcatheter aortic valve implantation (TAVI) have a pre-existing, permanent pacemaker (PPM) or receive one as a consequence of the procedure. We hypothesised that chronic pacing may have adverse effects on TAVI outcomes.Methods and resultsFour groups of patients undergoing TAVI in the Placement of Aortic Transcatheter Valves (PARTNER) trial and registries were compared: prior PPM (n=586), new PPM (n=173), no PPM (n=1612), and left bundle branch block (LBBB)/no PPM (n=160). At 1 year, prior PPM, new PPM and LBBB/no PPM had higher all-cause mortality than no PPM (27.4%, 26.3%, 27.7% and 20.0%, p<0.05), and prior PPM or new PPM had higher rehospitalisation or mortality/rehospitalisation (p<0.04). By Cox regression analysis, new PPM (HR 1.38, 1.00 to 1.89, p=0.05) and prior PPM (HR 1.31, 1.08 to 1.60, p=0.006) were independently associated with 1-year mortality. Surviving prior PPM, new PPM and LBBB/no PPM patients had lower LVEF at 1 year relative to no PPM (50.5%, 55.4%, 48.9% and 57.6%, p<0.01). Prior PPM had worsened recovery of LVEF after TAVI (Δ=10.0 prior vs 19.7% no PPM for baseline LVEF <35%, p<0.0001; Δ=4.1 prior vs 7.4% no PPM for baseline LVEF 35–50%, p=0.006). Paced ECGs displayed a high prevalence of RV pacing (>88%).ConclusionsIn the PARTNER trial, prior PPM, along with new PPM and chronic LBBB patients, had worsened clinical and echocardiographic outcomes relative to no PPM patients, and the presence of a PPM was independently associated with 1-year mortality. Ventricular dyssynchrony due to chronic RV pacing may be mechanistically responsible for these findings.Trial registration number(ClinicalTrials.gov NCT00530894).
Sustained clinical benefit of cardiac resynchronization therapy in non-LBBB patients with prolonged PR-interval: MADIT-CRT long-term follow-up
Objective In MADIT-CRT, patients with non-LBBB (right bundle branch block or nonspecific ventricular conduction delay) and a prolonged PR-interval derived significant clinical benefit from cardiac resynchronization therapy with defibrillator (CRT-D) compared to an implantable cardioverter defibrillator (ICD)-only. We aimed to study the long-term outcome of non-LBBB patients by baseline PR-interval with CRT-D versus ICD-only. Methods Non-LBBB patients ( n  = 534) were dichotomized based on baseline PR-interval: normal PR (PR < 230 ms), and markedly prolonged PR (PR ≥ 230 ms). The primary end point was heart failure (HF) or death. Secondary end points were HF only and all-cause death. Results In patients with a prolonged PR-interval, CRT-D treatment related to a 67 % significant reduction in the risk of HF/death (HR = 0.33, 95 % CI 0.16–0.69, p  = 0.003), 69 % decrease in HF (HR = 0.31, 95 % CI 0.14–0.68, p  = 0.003), and 76 % reduction in the risk of death (HR = 0.24, 95 % CI 0.07–0.80, p  = 0.020) compared to ICD-only (median follow-up 5.8 years). In normal PR-interval patients, CRT-D therapy was associated with a trend towards increased risk of HF/death (HR = 1.49, 95 % CI 0.98–2.25, p  = 0.061), and significantly increased mortality (HR = 2.27, 95 % CI 1.16–4.44, p  = 0.014). Significant statistical interaction with the PR-interval was demonstrated for all end points. Results were consistent for QRS 130–150 ms and QRS > 150 ms. Conclusion In MADIT-CRT, non-LBBB patients with a prolonged PR-interval derive sustained long-term clinical benefit with reductions in heart failure or death from CRT-D implantation, compared to an ICD-only. Our findings support implantation of CRT-D in non-LBBB patients with prolonged PR-interval irrespective of baseline QRS duration.
Adaptive versus conventional cardiac resynchronisation therapy in patients with heart failure (AdaptResponse): a global, prospective, randomised controlled trial
Continuous automatic optimisation of cardiac resynchronisation therapy (CRT), stimulating only the left ventricle to fuse with intrinsic right bundle conduction (synchronised left ventricular stimulation), might offer better outcomes than conventional CRT in patients with heart failure, left bundle branch block, and normal atrioventricular conduction. This study aimed to compare clinical outcomes of adaptive CRT versus conventional CRT in patients with heart failure with intact atrioventricular conduction and left bundle branch block. This global, prospective, randomised controlled trial was done in 227 hospitals in 27 countries across Asia, Australia, Europe, and North America. Eligible patients were aged 18 years or older with class 2–4 heart failure, an ejection fraction of 35% or less, left bundle branch block with QRS duration of 140 ms or more (male patients) or 130 ms or more (female patients), and a baseline PR interval 200 ms or less. Patients were randomly assigned (1:1) via block permutation to adaptive CRT (an algorithm providing synchronised left ventricular stimulation) or conventional biventricular CRT using a device programmer. All patients received device programming but were masked until procedures were completed. Site staff were not masked to group assignment. The primary outcome was a composite of all-cause death or intervention for heart failure decompensation and was assessed in the intention-to-treat population. Safety events were collected and reported in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT02205359, and is closed to accrual. Between Aug 5, 2014, and Jan 31, 2019, of 3797 patients enrolled, 3617 (95·3%) were randomly assigned (1810 to adaptive CRT and 1807 to conventional CRT). The futility boundary was crossed at the third interim analysis on June 23, 2022, when the decision was made to stop the trial early. 1568 (43·4%) of 3617 patients were female and 2049 (56·6%) were male. Median follow-up was 59·0 months (IQR 45–72). A primary outcome event occurred in 430 of 1810 patients (Kaplan-Meier occurrence rate 23·5% [95% CI 21·3–25·5] at 60 months) in the adaptive CRT group and in 470 of 1807 patients (25·7% [23·5–27·8] at 60 months) in the conventional CRT group (hazard ratio 0·89, 95% CI 0·78–1·01; p=0·077). System-related adverse events were reported in 452 (25·0%) of 1810 patients in the adaptive CRT group and 440 (24·3%) of 1807 patients in the conventional CRT group. Compared with conventional CRT, adaptive CRT did not significantly reduce the incidence of all-cause death or intervention for heart failure decompensation in the included population of patients with heart failure, left bundle branch block, and intact AV conduction. Death and heart failure decompensation rates were low with both CRT therapies, suggesting a greater response to CRT occurred in this population than in patients in previous trials. Medtronic.
Feasibility of RA–LV pacing in patients with symptomatic left bundle branch block: a pilot study
Several studies have reported the adverse effects of right ventricular apical pacing. Permanent His bundle pacing is proved to be the most physiological. But it can be technically difficult sometimes. One recent large multicenter randomized trial showed that pacing from left ventricular apex or mid-lateral wall has the greatest potential to prevent pacing-induced reduction of cardiac pump function (by maintaining left ventricular mechanical synchrony) and, therefore, can be considered as physiological site. In our study, we have wanted to see the outcome of left ventricular pacing through coronary sinus branch with active fixation bipolar lead as a routine pacing technique in patients with symptomatic left bundle branch block. In our study we have recruited 27 patients for left ventricular pacing through coronary sinus branch (as done in cardiac resynchronization therapy) with active fixation bipolar lead and 33 patients for right ventricular apical pacing (control) and compared left ventricular pacing with right ventricular apical pacing in patients with history of syncope with left bundle branch block in baseline electrocardiography who presented with atrio-ventricular block or prolonged HV interval (≥ 70 ms) on electrophysiology study in term of procedure and fluoroscopy time and short-term lead performance and left ventricular function. The results of our study showed that left ventricular pacing through a tributary of coronary sinus is associated with shortened QRS duration (21.10 ± 3.92 ms) and better LV function (higher left ventricular ejection fraction 64.00 ± 3.03 vs. 59.73 ± 6.73 and lower left ventricular diastolic internal diameter 4.58 ± 0.32 vs. 5.23 ± 0.40 cm) in comparison to right ventricular apical pacing. However, the total procedure time and fluoroscopy time was significantly higher (73.75 ± 11.02 vs. 63.32 ± 6.06 min and 7.08 ± 1.48 vs. 5.02 ± 1.39 min, respectively) in left ventricular pacing group. The results of this study indicate that transvenous left ventricular epicardial pacing may be an option for physiological pacing in patients with symptomatic left bundle branch block.
Survival with Cardiac-Resynchronization Therapy in Mild Heart Failure
In patients with reduced ejection fraction, mild heart failure, and prolonged QRS duration, CRT with a defibrillator improved survival, as compared with defibrillator therapy alone. The survival benefit was limited to patients with left bundle-branch block. The Multicenter Automatic Defibrillator Implantation Trial with Cardiac Resynchronization Therapy (MADIT-CRT) showed the safety and effectiveness of cardiac-resynchronization therapy (CRT) with a defibrillator (CRT-D) in patients with asymptomatic or mildly symptomatic heart failure, a reduced ejection fraction, and a prolonged QRS duration. 1 The study showed that treatment with CRT-D was associated with a 34% relative reduction in the risk of nonfatal heart-failure events or death from any cause, as compared with implantable cardioverter–defibrillator (ICD) therapy alone over a median follow-up period of 2.4 years. The benefit of CRT-D in the trial was primarily driven by a significant relative reduction of . . .
Effect of the 1-h bundle on mortality in patients with suspected sepsis in the emergency department: a stepped wedge cluster randomized clinical trial
PurposeThe efficacy of the 1-h bundle for emergency department (ED) patients with suspected sepsis, which includes lactate measurement, blood culture, broad-spectrum antibiotics administration, administration of 30 mL/kg crystalloid fluid for hypotension or lactate ≥ 4 mmol/L, remains controversial.MethodsWe carried out a pragmatic stepped-wedge cluster-randomized trial in 23 EDs in France and Spain. Adult patients with Sepsis-3 criteria or a quick sequential organ failure assessment (SOFA) score ≥ 2 or a lactate > 2 mmol/L were eligible. The intervention was the implementation of the 1-h sepsis bundle. The primary outcome was in-hospital mortality truncated at 28 days. Secondary outcomes included volume of fluid resuscitation at 24 h, acute heart failure at 24 h, SOFA score at 72 h, intensive care unit (ICU) length of stay, number of days on mechanical ventilation or renal replacement therapy, vasopressor free days, unnecessary antibiotic administration, and mortality at 28 days. 1148 patients were planned to be analysed; the study period ended after 873 patients were included.Results872 patients (mean age 66, 42% female) were analyzed: 387 (44.4%) in the intervention group and 485 (55.6%) in the control group. Median SOFA score was 3 [1–5]. Median time to antibiotic administration was 40 min in the intervention group vs 113 min in the control group (difference − 73 [95% confidence interval (CI) − 93 to − 53]). There was a significantly higher rate, volume, and shorter time to fluid resuscitation within 3 h in the intervention group. There were 47 (12.1%) in-hospital deaths in the intervention group compared to 61 (12.6%) in the control group (difference in percentage − 0.4 [95% CI − 5.1 to 4.2], adjusted relative risk (aRR) 0.81 [95% CI 0.48 to 1.39]). There were no differences between groups for other secondary endpoints.ConclusionsAmong patients with suspected sepsis in the ED, the implementation of the 1-h sepsis bundle was not associated with significant difference in in-hospital mortality. However, this study may be underpowered to report a statistically significant difference between groups.
AUX/LAX Genes Encode a Family of Auxin Influx Transporters That Perform Distinct Functions during Arabidopsis Development
Auxin transport, which is mediated by specialized influx and efflux carriers, plays a major role in many aspects of plant growth and development. AUXIN1 (AUX1) has been demonstrated to encode a high-affinity auxin influx carrier. In Arabidopsis thaliana, AUX1 belongs to a small multigene family comprising four highly conserved genes (i.e., AUX1 and LIKE AUX1 [LAX] genes LAX1, LAX2, and LAX3). We report that all four members of this AUX/LAX family display auxin uptake functions. Despite the conservation of their biochemical function, AUX1, LAX1, and LAX3 have been described to regulate distinct auxin-dependent developmental processes. Here, we report that LAX2 regulates vascular patterning in cotyledons. We also describe how regulatory and coding sequences of AUX/LAX genes have undergone subfunctionalization based on their distinct patterns of spatial expression and the inability of LAX sequences to rescue aux1 mutant phenotypes, respectively. Despite their high sequence similarity at the protein level, transgenic studies reveal that LAX proteins are not correctly targeted in the AUX1 expression domain. Domain swapping studies suggest that the N-terminal half of AUX1 is essential for correct LAX localization. We conclude that Arabidopsis AUX/LAX genes encode a family of auxin influx transporters that perform distinct developmental functions and have evolved distinct regulatory mechanisms.
Success and complication rates of conduction system pacing: a meta-analytical observational comparison of left bundle branch area pacing and His bundle pacing
Background Left bundle branch area pacing (LBBAP) and His bundle pacing (HBP) are the main strategies to achieve conduction system pacing (CSP), but only observational studies with few patients have compared the two pacing strategies, sometimes with unclear results given the different definitions of the feasibility and safety outcomes. Therefore, we conducted a meta-analysis aiming to compare the success and complications of LBBAP versus HBP. Methods We systematically searched the electronic databases for studies published from inception to March 22, 2023, and focusing on LBBAP versus HBP. The study endpoints were CSP success rate, device-related complications, CSP lead-related complications and non-CSP lead-related complications. Results Fifteen observational studies enrolling 2491 patients met the inclusion criteria. LBBAP led to a significant increase in procedural success [91.1% vs 80.9%; RR: 1.15 (95% CI: 1.08–1.22); p < 0.00001] with a significantly lower complication rate [1.8% vs 5.2%; RR: 0.48 (95% CI: 0.29–0.78); p = 0.003], lead-related complications [1.1% vs 4.3%; RR: 0.38 (95% CI: 0.21–0.72); p = 0.003] and lead failure/deactivation [0.2% vs 3.9%; RR: 0.16 (95% CI: 0.07–0.35); p < 0.00001] than HBP. No significant differences were found between CSP lead dislodgement and non-CSP lead-related complications. Conclusion This meta-analysis of observational studies showed a higher success rate of LBBAP compared to HBP with a lower incidence of complications.