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His-bundle pacing has demonstrated feasibility in numerous adult studies to reverse and prevent pacing-induced cardiomyopathy, however, is met with higher capture thresholds with deployment sheaths designed for adults with his-bundles in the typical location. To describe 24 pediatric and adult congenital patients post-physiologic pacing. Patients at the University of Minnesota Masonic Childrens Hospital with congenital complete heart block or congenital heart disease and atrioventricular block presented for pacemaker placement between November 2019 and January 2021. Twenty-four patients had attempted his-bundle placement using either Medtronics C315 or C308 sheaths and 3830 leads except for 3 patients who had Boston Scientifics His system with the Shape 3 sheath and 7842 leads. Twenty-four total patients underwent physiologic pacing (23 his-bundle, 13 female, 11 male) with median age of 14 years (range 8-39 years) with median weight of 51 kg (range 21.2-81 kg) with five right-sided implants performed. Twelve patients had congenital heart disease including atrioventricular canal defects, tetralogy of Fallot, and ventricular septal defect repairs (nine patients with ventricular septal defect repairs). Twelve patients had selective His-bundle pacing (six with congenital heart disease). Median threshold to capture was 0.5 V at 0.4 ms (range 0.4 to 1.1 V at 0.4 ms), impedance 570 ohms (range 456-1140 ohms), and sensing median of 9.7 mV (range 1.5-13.8 mV if present). The median follow-up time was 610 days (range 240-760 days). No complications occurred peri-procedurally or during follow-up. His-bundle pacing is feasible in pediatric and congenital heart disease patients.

Smartwatches provide health tracking in various ways and there has been a recent rise in reporting cardiac arrhythmias. While original studies focused on atrial fibrillation, fewer reports have been made on other arrhythmias especially in pregnancy. We report a pregnant patient who presented at 34 weeks' gestation with palpitations. An ECG recorded through her Apple Watch showed ventricular tachycardia. Hospital ECG confirmed monomorphic ventricular tachycardia likely caused by increased sympathetic tone from the gravid state. She was admitted to the cardiac intensive care unit for close monitoring with intravenous anti-arrhythmic agents; however, the rhythm persisted. She underwent a caesarean delivery and the arrhythmia resolved post partum. She later underwent a catheter ablation, after which she discontinued all anti-arrhythmic medications with no recurrence. This case highlights the importance of requesting relevant digital health information, if available, from patients in our modern era. Controlled clinical studies are needed to validate such practices.

Background Methods Results Conclusions Recent studies have demonstrated an obesity paradox, where obese patients with cardiovascular disease have a better outcome compared to those with normal weight. However, the effect of obesity and body mass index (BMI) on the outcome of patients with cardiac resynchronization therapy (CRT) devices remains unclear. The current study aims to investigate this relationship using all available published data.We systematically reviewed studies from Medline and EMBASE databases from inception to January 2024. Eligible studies must investigate the association between BMI status and all‐cause mortality in individuals with CRT devices. Relative risk (RR) or hazard ratio (HR) and 95% CIs were retrieved from each study and combined using the generic inverse variance method.A total of 12 cohort studies were included in the meta‐analysis. Pooled analysis showed that overweight and obesity patients had lower all‐cause mortality compared to those with normal body weight with the pooled risk ratios (RR) for overweight of 0.77 (95% CI 0.69–0.87, I2 47%) and for obesity of 0.81 (95% CI 0.67–0.97, I2 59%). Conversely, the underweight exhibited higher all‐cause mortality than the group with normal weight, with a pooled RR of 1.37 (95% CI 1.14–1.64, I2 0%). Additionally, higher BMI as continuous data was associated with decreased all‐cause mortality, with a pooled HR of 0.94 (95% CI 0.89–0.98, I2 72%).The pooled analyses observed an obesity paradox in patients with CRT, where overweight and obesity were associated with reduced all‐cause mortality, while underweight individuals exhibited higher all‐cause mortality. Further research is necessary to investigate the underlying mechanisms and their implications for clinical practice. [ABSTRACT FROM AUTHOR]

Background: Gap junction remodeling is an important cause of ventricular arrhythmia in heart failure. However, it remains unclear whether renal denervation (RDN) regulates gap junction remodeling in heart failure. To explore the effect of RDN on gap junction remodeling in dogs with high-pacing-induced heart failure. Methods: Fifteen dogs were randomly divided into control (n=5), heart failure (HF) (n=5), and RDN+HF (n=5) group. A high-pacing-induced-heart failure model was established using rapid right ventricular pacing for 4 weeks. The RDN+HF group underwent surgical and chemical ablation of both renal arteries before 4 weeks rapid right ventricular pacing. After 4 weeks, echocardiography, High-Performance Liquid Chromatography-Mass Spectrometry test for norepinephrine and epinephrine, and pathological analysis were performed in the above 3 groups. Further, immunohistochemical staining was used to detect tyrosine hydroxylase, ChaT, connexin 43 (Cx43), and connexin 40 (Cx40). Connexin 43 and Cx40 expression was detected by western blotting. Transmission electron microscopy was used to observe the gap junction. Results: Compared to the control group, myocardial fibrosis and sympathetic hyperactivity were observed in the HF group. Immunohistochemical staining and western blotting showed that Cx40 expression and Cx43 expression was significantly reduced in the HF group. Compared with the HF group, the RDN+HF group showed reduced sympathetic hyperactivity, Cx40 expression, Cx40/Cx43 ratio, and increased Cx43 expression. Conclusion: Renal denervation alleviates gap junction remodeling in high-pacinginduced heart failure dogs. [ABSTRACT FROM AUTHOR]

To evaluate the effect of body position on transesophageal atrial pacing (TEAP) in dogs. Prospective, experimental trial. A total of eight mixed-breed dogs, median body mass 25 kg (range 11–31 kg). TEAP was performed using a 6 Fr (2 mm) pacing catheter introduced transorally and positioned in the lower esophagus in left lateral recumbency. The catheter was withdrawn in 5 mm increments until successful TEAP. The minimum pacing threshold (MPT) was determined at each 5 mm increment until atrial capture could not be achieved at a maximal pulse amplitude of 40 mA. The zone of capture (ZOC) was the total distance over which TEAP was achieved. The same process was repeated in right lateral, ventral and dorsal recumbency. A linear mixed model was used to assess the impact of body position on TEAP and ZOC. TEAP was achieved in all body positions. There was significant random effect of individual dogs on ZOC (p = 0.048) but not on MPT (p = 0.109). MPT was 11.56 ± 8.65 mA (mean ± SD), 8.43 ± 2.29 mA, 10.63 ± 6.91 mA and 10 ± 7.44 mA for dorsal, left and right lateral, and ventral recumbency, respectively. ZOC was 5.12 ± 2.08 cm, 6.35 ± 2.41 cm, 5.94 ± 3.23 cm and 5.31 ± 2.2 cm for dorsal, left lateral and right lateral, and ventral recumbency, respectively. Neither ZOC (p = 0.363) nor MPT (p = 0.716) varied significantly between body positions. TEAP can be performed successfully in all body positions in dogs. Body position did not significantly influence MPT or ZOC values for TEAP. Further studies are needed to compare the efficacy of TEAP with the efficacy of standard pharmacological therapy for management of bradycardia during general anesthesia in dogs. [ABSTRACT FROM AUTHOR]

In order to facilitate cardiovascular research to develop non-invasive optical heart pacing methods, we have generated a double-transgenic Drosophila melanogaster (fruit fly) model suitable for optogenetic pacing. We created a fly stock with both excitatory H134R-ChR2 and inhibitory eNpHR2.0 opsin transgenes. Opsins were expressed in the fly heart using the Hand-GAL4 driver. Here we describe Hand > H134R-ChR2; eNpHR2.0 model characterization including bi-directional heart control (activation and inhibition) upon illumination of light with distinct wavelengths. Optical control and real-time visualization of the heart function were achieved non-invasively using an integrated light stimulation and optical coherence microscopy (OCM) system. OCM produced high-speed and high-resolution imaging; simultaneously, the heart function was modulated by blue (470 nm) or red (617 nm) light pulses causing tachycardia, bradycardia and restorable cardiac arrest episodes in the same animal. The irradiance power levels and illumination schedules were optimized to achieve successful non-invasive bi-directional heart pacing in Drosophila larvae and pupae. Optical control and real-time beating heart visualization of Hand > H134R-ChR2; eNpHR2.0 Drosophila were achieved non-invasively using an integrated light stimulation and optical coherence microscopy (OCM) system. [ABSTRACT FROM AUTHOR]

Background Objective Methods Results Conclusion Cardiac resynchronization therapy (CRT) improves ventricular function, but a positive response to CRT is often limited due to left ventricular (LV) lead placement in a suboptimal position. Complex coronary venous anatomy can hinder the placement of an LV lead in the target vessel, leading to poor CRT response.To report experience with snare‐assisted LV lead delivery in CRT and compare outcomes with the conventional LV lead delivery.This is a single‐center retrospective case–control study of CRT implants between 2016 and 2021. Snare‐assisted lead delivery was performed in cases where conventional lead placement failed or when a preferred target vessel had anatomy amenable to the technique. Safety and outcomes were compared to conventional LV lead placement cases.Among 180 CRT cases, 33 were snare‐assisted, and 147 were conventional LV lead placements. Median follow‐up was 924 days in the snare and 618.5 days in the control group. The lead placement was successful in 28/33 snare and 138/147 control cases. A mid‐vessel segment was attained in 89.3% of snare and 72.5% of control cases(p = .03). The apical position was more frequently observed in the control group (26.8% vs. 7.1%, p = .03). All‐cause mortality trended lower in the snare group (6.1%) compared to (17.1%) in the control group (p = .13).Snare‐assisted LV lead delivery is a safe and effective technique that can be utilized for overcoming complex venous anatomy. [ABSTRACT FROM AUTHOR]

Objectives: This study assessed how exposure to slow (SBM) versus fast beat music (FBM) during high-intensity rowing intervals affects performance, heart rate (HR), lactate levels, relative perceived exertion (RPE), and recovery. Methods: The A/B crossover design involved 21 participants performing 5 × 500 m rowing intervals under two conditions: FBM and SBM. Primary endpoint was the difference in total rowing time. Secondary endpoints included average HR, average RPE as well as rowing interval times, RPE, and HR per interval. For exploratory purpose, HR and lactate drop during the initial 5 min post completion was analyzed. Results: Listening to FBM resulted in significantly shorter total rowing times (p = 0.009, rB = 0.59), especially during the 1st interval. The 1st interval was also significantly faster than intervals 2-5 (p < 0.001), with the greatest performance drop between the 1st and 2nd interval during FBM. Average HR was significantly lower when listening to SBM (p = 0.03, rB = 0.48), while average RPE showed no significant difference (p = 0.47, rB = 0.02). Lactate values after interval 5 were significantly lower in SBM (p = 0.05, rB = 0.41), but no significant difference was found for lactate drop (p = 0.21, rB = 0.21). However, participants exhibited a higher HR drop rate with SBM (p = 0.05, rB = 0.42). Conclusion: FBM improved performance without increasing RPE, while SBM proved superior for recovery. Systematic customization of music based on intended training stimuli holds broad potential for the competitive sports, fitness, and health sector. [ABSTRACT FROM AUTHOR]

Background: Left Bundle Branch Area Pacing (LBBaP) is a cardiac pacing technique designed to mimic the natural conduction system of the heart. Traditional right ventricular apical pacing has been associated with increased risks of heart failure and atrial fibrillation. This study investigates the stability and safety of LBBaP using the Selectra 3D sheath (Biotronik) with an inclined angle for implanting the Solia S lead (Biotronik, SE & Co, KG). Methods: A single-center retrospective study was conducted on 25 patients who underwent LBBaP implantation using the Selectra 3D sheath at our hospital. The procedure involved inserting the Solia S lead into the interventricular septum at an inclined angle. Surgical and postoperative data were collected, including the success rate, depth and angle of electrode insertion, complications, and follow-up data. Results: The success rate of LBBaP implantation was 92%. The length of electrode insertion into the interventricular septum ranged from 12 to 23.0 mm, with an average of 18.1 ± 3.08 mm. The angle formed between the electrode and the septum ranged from 0° to 57.3°, with an average of 35.14°±14.31°. During the 3-month follow-up period, pacing parameters remained stable, and no complications were reported. Conclusions: LBBaP implantation using the Selectra 3D sheath with an inclined angle for the Solia S implantation demonstrates stability and safety. The procedure boasts a high success rate and offers an effective option for LBBaP implantation. [ABSTRACT FROM AUTHOR]

This article discusses several hot topics in the field of cardiovascular health. It includes a review of left atrial appendage closure (LAAC) as an alternative treatment for stroke prevention in patients with atrial fibrillation (AF). The article also examines the safety of home treatment for acute pulmonary embolism (PE) patients and the efficacy of pulmonary artery (PA)-guided therapy for chronic heart failure (HF) patients. Additionally, the article presents a novel tool for arrhythmic risk stratification in patients with desmoplakin gene variants and evaluates the risk of thromboembolic events after COVID-19 vaccination in patients with AF. The authors provide insights, data, and recommendations for each topic, highlighting the need for further research and individualized care. [Extracted from the article]

Background and Aims In patients with chronic heart failure (HF), the MONITOR-HF trial demonstrated the efficacy of pulmonary artery (PA)-guided HF therapy over standard of care in improving quality of life and reducing HF hospitalizations and mean PA pressure. This study aimed to evaluate the consistency of these benefits in relation to clinically relevant subgroups. Methods The effect of PA-guided HF therapy was evaluated in the MONITOR-HF trial among predefined subgroups based on age, sex, atrial fibrillation, diabetes mellitus, left ventricular ejection fraction, HF aetiology, cardiac resynchronization therapy, and implantable cardioverter defibrillator. Outcome measures were based upon significance in the main trial and included quality of life-, clinical-, and PA pressure endpoints, and were assessed for each subgroup. Differential effects in relation to the subgroups were assessed with interaction terms. Both unadjusted and multiple testing adjusted interaction terms were presented. Results The effects of PA monitoring on quality of life, clinical events, and PA pressure were consistent in the predefined subgroups, without any clinically relevant heterogeneity within or across all endpoint categories (all adjusted interaction P -values were non-significant). In the unadjusted analysis of the primary endpoint quality-of-life change, weak trends towards a less pronounced effect in older patients (P interaction =.03; adjusted P interaction =.33) and diabetics (P interaction =.01; adjusted P interaction =.06) were observed. However, these interaction effects did not persist after adjusting for multiple testing. Conclusions This subgroup analysis confirmed the consistent benefits of PA-guided HF therapy observed in the MONITOR-HF trial across clinically relevant subgroups, highlighting its efficacy in improving quality of life, clinical, and PA pressure endpoints in chronic HF patients. [ABSTRACT FROM AUTHOR]

Background: Heart failure (HF) remains a challenging healthcare issue necessitating innovative therapies like cardiac resynchronization–defibrillation therapy (CRT-D). However, the definition of a CRT-D response lacks uniformity, impeding effective clinical evaluation. This study explores diverse CRT-D responder definitions encompassing functional, echocardiographic and laboratory criteria. Materials & Methods: A single-center study involving 132 CRT-D patients scrutinized responder criteria including NYHA stage, LVEF increase and proBNP decrease. Statistical analyses such as Kaplan–Meier curves and Cox hazard regression were employed to evaluate responder characteristics and survival outcomes. Results: Responder rates varied across criteria, revealing nuanced patient profiles. CRT-D responders defined by NYHA decrease, LVEF increase or proBNP decrease exhibit improved survival rates after 2 and 3 years (p < 0.050). Young age, absence of recent myocardial infarction and normal right ventricular echocardiographic parameters emerge as predictors for positive response. In part, drug-based HF therapy correlates with increased responder rates. Cox regression identified LVEF ≥ 5% and proBNP decrease ≥ 25% as independent predictors of extended survival. Conclusions: CRT-D responder definitions exhibit considerable variability, emphasizing the need for a nuanced patient-centered approach. Factors like right ventricular function, drug therapy, atrial fibrillation and renal function influence responses. This study enriches our understanding of CRT-D response and contributes to the foundation for personalized HF management. [ABSTRACT FROM AUTHOR]

Background: When compared to biventricular pacing, fusion CRT pacing was linked to a decreased incidence of atrial fibrillation (AF). There is a gap in the knowledge regarding exclusive fusion CRT without interference with RV pacing, and all the current data are based on populations of patients with intermittent fusion pacing. Purpose: To assess left atrium remodeling and AF incidence in a real-life population of permanent fusion CRT-P. Methods: Retrospective data were analyzed from a cohort of patients with exclusive fusion CRT-P. Device interrogation, exercise testing, transthoracic echocardiography (TE), and customized medication optimization were all part of the six-monthly individual follow-up. Results: Study population: 73 patients (38 males) with non-ischemic dilated cardiomyopathy aged 63.7 ± 9.3 y.o. Baseline characteristic: QRS 159.8 ± 18.2 ms; EF 27.9 ± 5.1%; mitral regurgitation was severe in 38% of patients, moderate in 47% of patients, and mild in 15% of patients; 43% had type III diastolic dysfunction (DD), 49% had type II DD, 8% had type I DD. Average follow-up was 6.4 years ± 27 months: 93% of patients were responders (including 31% super-responders); EF increased to 40.4 ± 8.5%; mitral regurgitation decreased in 69% of patients; diastolic profile improved in 64% of patients. Paroxysmal and persistent AF incidence was 11%, with only 2% of patients developing permanent AF. Regarding LA volume, statistically significant LA reverse remodeling was observed. Conclusions: Exclusive fusion CRT-P was associated with important LA reverse remodeling and a low incidence of AF. [ABSTRACT FROM AUTHOR]

Left bundle branch area pacing (LBBPa) is an innovative technique for physiological pacing. Compared with His bundle pacing, LBBPa provides better pacing thresholds, lower rates of macrodislodgment, and a reliable strategy for cardiac resynchronization. LBBPa traditionally employs lumenless leads (LLL), which are characterized by small lead bodies and a fixed helix design. These features guarantee stability, avoid helix retraction, and facilitate easier septal penetration, all contributing to an advantageous learning curve. On the other hand, stylet-driven pacing leads (SDL) have shown comparable success rates related to lumenless pacing leads, although they carry risks of helix retraction and lead fracture. SDL have been increasingly employed with favorable results, as they provide good maneuverability and support during implantation with continuous monitoring of ECG-paced morphology. Different manufacturers are offering a variety of SDL, and new dedicated tools are being developed to simplify lead implantation. In this review, we examine the procedural techniques, advantages, and limitations of the most commonly used pacing leads and tools for LBBPa, and we summarize the complications associated with both lumenless leads (LLL) and stylet-driven leads (SDL). [ABSTRACT FROM AUTHOR]

The impact of age (≥ 85 vs < 85 years) on clinical outcomes and pacemaker performance of conduction system pacing (CSP) compared to right ventricular pacing (RVP) were examined. Consecutive patients from a prospective, observational, multicenter study with pacemakers implanted for bradycardia were studied. The primary endpoint was a composite of heart failure (HF)-hospitalizations, pacing-induced cardiomyopathy requiring cardiac resynchronization therapy or all-cause mortality. Secondary endpoints were acutely successful CSP, absence of pacing-complications, optimal pacemaker performance defined as pacing thresholds < 2.5 V, R-wave amplitude ≥ 5 V and absence of complications, threshold stability (no increases of > 1 V) and persistence of His-Purkinje capture on follow-up. Among 984 patients (age 74.1 ± 11.2 years, 41% CSP, 16% ≥ 85 years), CSP was independently associated with reduced hazard of the primary endpoint compared to RVP, regardless of age-group (< 85 years: adjusted hazard ratio [AHR] 0.63, 95% confidence interval [CI] 0.40–0.98; ≥ 85 years: AHR 0.40, 95% CI 0.17–0.94). Among patients with CSP, age did not significantly impact the secondary endpoints of acute CSP success (86% vs 88%), pacing complications (19% vs 11%), optimal pacemaker performance (64% vs 69%), threshold stability (96% vs 96%) and persistent His-Purkinje capture (86% vs 91%) on follow-up (all p > 0.05). CSP improves clinical outcomes in all age-groups, without compromising procedural safety or pacemaker performance in the very elderly. [ABSTRACT FROM AUTHOR]

This article provides a review of the safety of particle radiotherapy in patients with cardiac implantable electronic devices (CIEDs). The study found that the rate of CIED interactions during particle therapy was low, with no serious adverse events reported. The most common malfunctions were reprogrammable resets and battery depletions, but there were no irreversible malfunctions or adverse patient outcomes. Overall, particle therapy appears to be safe for patients with CIEDs, but further research is needed to fully understand the risks and benefits. The review also emphasizes the importance of individualized treatment and close monitoring of CIED function during particle therapy to prevent any potential adverse outcomes. [Extracted from the article]

Without intervention, cardiac arrhythmias pose a risk of fatality. However, timely intervention can be challenging in environments where transporting a large, heavy defibrillator is impractical, or emergency surgery to implant cardiac stimulation devices is not feasible. Here, we introduce an injectable cardiac stimulator, a syringe loaded with a nanoparticle solution comprising a conductive polymer and a monomer that, upon injection, forms a conductive structure around the heart for cardiac stimulation. Following treatment, the electrode is cleared from the body, eliminating the need for surgical extraction. The mixture adheres to the beating heart in vivo without disrupting its normal rhythm. The electrofunctionalized injectable cardiac stimulator demonstrates a tissue-compatible Young's modulus of 21 kPa and a high conductivity of 55 S/cm. The injected electrode facilitates electrocardiogram measurements, regulates heartbeat in vivo, and rectifies arrhythmia. Conductive functionality is maintained for five consecutive days, and no toxicity is observed at the organism, organ, or cellular levels. Heart pacing devices are bulky or rely on surgery. Here, the authors present an injectable cardiac stimulator based on a nanoparticle solution which attaches to the heart and forms a conductive path to the skin for external connection. It can regulate heartbeats and is thereafter cleared from the body. [ABSTRACT FROM AUTHOR]

BACKGROUND: A dual-chamber leadless pacemaker system has been designed for atrioventricular synchronous pacing using wireless, beat-to-beat, implant-to-implant (i2i) communication between distinct atrial and ventricular leadless pacemakers. The atrioventricular synchrony achieved across various ambulatory scenarios has yet to be systematically evaluated. METHODS: A prospective, single-arm, unblinded, multicenter, international clinical trial of the leadless pacemaker system was conducted in patients with a conventional dual-chamber pacing indication enrolled from February 2022 to March 2023. Leadless pacemaker systems were implanted, and 12-lead Holter electrocardiographic recordings were collected 3 months after implantation over various postures/activities: sitting, supine, left lateral recumbent, right lateral recumbent, standing, normal walk, and fast walk. An independent Holter core laboratory performed a manual adjudication of the percent of atrioventricular synchronous beats using the standard 300-millisecond PR interval limit. Atrium-to-ventricle and ventricle-to-atrium i2i communication success rates were also assessed. Post hoc summary statistics describing the relationships between atrioventricular synchrony and i2i success, posture/activity, implantation indication, atrioventricular event, and heart rate were calculated. RESULTS: In the evaluable population (n=384 of 464 enrolled [83%]; 61% male; age, 70 years; weight, 82 kg; 60% ejection fraction; 95% of beats evaluable), the mean atrioventricular synchrony of 98% of beats observed across all postures using the standard 300-millisecond limit was greater than both atrial-to-ventricular i2i (94%) and ventricular-to-atrial i2i (94%; P<0.001), exceeding both i2i values in 95% of patients. Atrioventricular synchrony was achieved in >95% of evaluable beats across all postures/activities, implantation indications, atrioventricular paced/sensed event combinations, and heart rate ranges (including >100 bpm). CONCLUSIONS: This dual-chamber leadless pacemaker system demonstrated atrioventricular synchrony in 98% of evaluable beats at 3 months after implantation. Atrioventricular synchrony was maintained across postures/activities and remained robust for heart rates >100 bpm. [ABSTRACT FROM AUTHOR]

Objective: The feasibility of the conduction system pacing (CSP) upgrade as an alternative modality to the traditional biventricular pacing (BiVP) upgrade in patients with pacemaker-induced cardiomyopathy (PICM) remains uncertain. This study sought to compare two modalities of CSP (His bundle pacing (HBP) and left bundle branch pacing (LBBP)) with BiVP and no upgrades in patients with pacing-induced cardiomyopathy. Methods: This retrospective analysis comprised consecutive patients who underwent either BiVP or CSP upgrade for PICM at the cardiac department from 2017 to 2021. Patients with a follow-up period exceeding 12 months were considered for the final analysis. Results: The final group of patients who underwent upgrades included 48 individuals: 11 with BiVP upgrades, 24 with HBP upgrades, and 13 with LBBP upgrades. Compared to the baseline data, there were significant improvements in cardiac performance at the last follow-up. After the upgrade, the QRS duration (127.81 ± 31.89 vs 177.08 ± 34.35 ms, p < 0.001), NYHA class (2.28 ± 0.70 vs 3.04 ± 0.54, p < 0.05), left ventricular end-diastolic diameter (LVEDD) (54.08 ± 4.80 vs 57.50 ± 4.85mm, p < 0.05), and left ventricular ejection fraction (LVEF) (44.46% ± 6.39% vs 33.15% ± 5.25%, p < 0.001) were improved. There was a noticeable improvement in LVEF in the CSP group (32.15% ± 3.22% vs 44.95% ± 3.99% (p < 0.001)) and the BiVP group (33.90% ± 3.09% vs 40.83% ± 2.99% (p < 0.001)). The changes inQRS durationweremore evident in CSP than in BiVP (56.65 ± 11.71 vs 34.67 ± 13.32, p < 0.001). Similarly, the changes in LVEF (12.8 ± 3.66 vs 6.93 ± 3.04, p < 0.001) and LVEDD (5.80 ± 1.71 vs 3.16 ± 1.35, p < 0.001) were greater in CSP than in BiVP. The changes in LVEDD (p = 0.549) and LVEF (p = 0.570) were similar in the LBBP and HBP groups. The threshold in LBBP was also lower than that in HBP (1.01 ± 0.43 vs 1.33 ± 0.32 V, p = 0.019). Conclusion: The improvement of clinical outcomes in CSP was more significant than in BiVP. CSPmay be an alternative therapy to CRT for patients with PICM. LBBP would be a better choice than HBP due to its lower thresholds. [ABSTRACT FROM AUTHOR]

The current gold standard in device therapy for advanced heart failure (HF), which has been firmly established in HF management for more than 25 years, is classical biventricular pacing (BiV-CRT). In the last decade, a new pacing modality called conduction system pacing (CSP) has emerged as a variant for advanced cardiac device therapy. It provides pacing with preserved intrinsic cardiac activation by direct stimulation of the specific cardiac conduction system. The term CSP integrates the modalities of HIS bundle pacing (HBP) and left bundle branch area pacing (LBBAP), both of which have provided convincing data in smaller randomized and big non-randomized studies for the prevention of pacemaker-induced cardiomyopathy and for providing effective cardiac resynchronization therapy in patients with classical CRT-indication (primary approach or after failed CRT). Recent American guidelines proposed the term "cardiac physiological pacing" (CPP), which summarizes CSP including left ventricular septal pacing (LVSP), a technical variant of LBBAP together with classical BiV-CRT. The terms HOT-CRT (HIS-optimized CRT) and LOT-CRT (LBBP-optimized CRT) describe hybrid technologies that combine CSP with an additional coronary-sinus electrode, which is sometimes useful in patients with advanced HF and diffuse interventricular conduction delay. If CSP continues providing promising data that can be confirmed in big, randomized trials, it is likely to become the new gold standard for patients with an expected high percentage of pacing (>20%), possibly also for cardiac resynchronization therapy. CSP is a sophisticated new treatment option that has the potential to raise the term "cardiac resynchronization therapy" to a new level. The aim of this review is to provide basic technical, anatomical, and functional knowledge of these new pacemaker techniques in order to facilitate the understanding of the different modalities, as well as to provide an up-to-date overview of the existing randomized and non-randomized evidence, particularly in direct comparison to right ventricular and classical biventricular pacing. [ABSTRACT FROM AUTHOR]

Brugada syndrome (BrS) is a cardiac electrophysiological disease with unknown etiology, associated with sudden cardiac death. Symptomatic patients are treated with implanted cardiac defibrillator, but no risk stratification strategy is effective in patients that are at low to medium arrhythmic risk. Cardiac computational modeling is an emerging tool that can be used to verify the hypotheses of pathogenesis and inspire new risk stratification strategies. However, to obtain reliable results computational models must be validated with consistent experimental data. We reviewed the main electrophysiological and structural variables from BrS clinical studies to assess which data could be used to validate a computational approach. Activation delay in the epicardial right ventricular outflow tract is a consistent finding, as well as increased fibrosis and subclinical alterations of right ventricular functional and morphological parameters. The comparison between other electrophysiological variables is hindered by methodological differences between studies, which we commented. We conclude by presenting a recent theory unifying electrophysiological and structural substrate in BrS and illustrate how computational modeling could help translation to risk stratification. [ABSTRACT FROM AUTHOR]

Introduction: Leadless pacemakers are associated with a low risk of infection, so indications for their removal are rare. One can expect that the dwell time of the device correlates with a more difficult removal, but it has not been proved so far. Methods and Results: We present a case of a patient in whom MICRA transcatheter pacing system was successfully removed with nondedicated commercially available tools, 70 months after implantation. Conclusion: A successful removal of the MICRA leadless pacemaker is possible, and may be safe even many years after the device implantation, despite a lack of dedicated tools. Due to the potential risk of complications, the benefits and risks of the procedure should be weighted before making a final decision. [ABSTRACT FROM AUTHOR]

Introduction: The association between paced LVAT and cardiac structure and function at baseline, as well as whether longer LVAT is associated with worse cardiac reverse remodeling in patients with heart failure (HF) and left bundle branch block (LBBB) has not been well investigated. The purpose of this study is to investigate the association between paced LVAT and baseline echocardiographic parameters and cardiac reverse remodeling at follow‐up. Methods: Patients with HF and LBBB receiving successful left bundle branch pacing (LBBP) from June 2018 to April 2023 were enrolled and grouped based on paced LVAT. NT‐proBNP and echocardiographic parameters were recorded during routine follow‐up. The relationships between paced LVAT and echocardiographic parameters at baseline and follow‐up were analyzed. Results: Eighty‐three patients were enrolled (48 males, aged 65 ± 9.8, mean LVEF 32.1 ± 7.5%, mean LVEDD 63.0 ± 8.5 mm, median NT‐proBNP 1057[513–3158] pg/mL). The paced QRSd was significantly decreased (177 ± 17.9 vs. 134 ± 18.5, p <.001) and median paced LVAT was 80[72–88] ms. After a median follow‐up of 12[9–29] months, LVEF increased to 52.1 ± 11.2%, LVEDD decreased to 52.6 ± 8.8 mm, and NT‐proBNP decreased to 215[73–532]pg/mL. Patients were grouped based on paced LVAT: LVAT < 80 ms (n = 39); 80 ≤ LVAT < 90 ms (n = 24); LVAT ≥ 90 ms (n = 20). Patients with longer LVAT had larger LVEDD and lower LVEF (LVEDDbaseline: p <.001; LVEFbaseline: p =.001). The difference in LVEF6M was statistically significant among groups (p <.001) and patients with longer LVAT had lower LVEF6M, while the difference in LVEF1Y was not seen (p =.090). There was no significant correlation between ΔLVEF6M‐baseline, ΔLVEF1Y‐6M and LVAT respectively (ΔLVEF6M‐baseline: p =.261, r = −.126; ΔLVEF1Y‐6M: p =.085, r =.218). Conclusion: Long paced LVAT was associated with worse echocardiographic parameters at baseline, but did not affect the cardiac reverse remodeling in patients with HF and LBBB. Those with longer LVAT required longer time to recover. [ABSTRACT FROM AUTHOR]

The article presents a case study of a patient with ventricular tachycardia originating from the para-Hisian region, where detailed electrophysiological mapping and pacing maneuvers were used to identify the reentrant mechanism. It also discusses the effectiveness of entrainment pacing in determining the optimal ablation site, challenges associated with ablation in this anatomical region, and the role of detailed electroanatomical mapping in avoiding damage to the AV conduction system.

Introduction: Left bundle branch area pacing is an alternative to biventricular pacing. In this study, we aim to summarize the available evidence on the feasibility, efficacy, and safety of left bundle branch block area pacing (LBBAP). Objectives: The study summarizes the available evidence on the feasibility, efficacy, and safety of left bundle branch block area pacing (LBBAP). Background: Cardiac resynchronization therapy (CRT) reduced mortality and hospitalizations in heart failure (HF) patients with a left ventricular ejection fraction (LVEF) ≤ 35% and concomitant LBBB. Recently LBBAP has been studied as a more physiological alternative to achieve CRT. Method: A search of PubMed, EMBASE, and Cochrane databases were performed to identify studies examining the role of LBBAP for CRT in heart failure. Comprehensive meta‐analysis version 4 was used for meta‐regression to examine variables that contribute to data heterogeneity. Result: Eighteen studies, 17 observational and one randomized controlled trial (RCT) were examined. A total of 3906 HF patients who underwent CRT (2036 LBBAP vs. 1870 biventricular pacing [BVP]) were included. LBBAP was performed successfully in 90.4% of patients. Compared to baseline, LBBAP was associated with a reduction in QRS duration (MD: −47.23 ms 95% confidence interval [CI]: −53.45, −41.01), an increase in LVEF (MD: 15.22%, 95% CI: 13.5, 16.94), and a reduction in NYHA class (MD: −1.23, 95% CI: −1.41, −1.05). Compared to BVP, LBBAP was associated with a significant reduction in QRS duration (MD: −20.69 ms, 95% CI: −25.49, −15.88) and improvement in LVEF (MD: 4.78%, 95% CI: 3.30, 6.10). Furthermore, LBBAP was associated with a significant reduction in HF hospitalization (odds ratio [OR]: 0.44, 95% CI: 0.34, 0.56) and all‐cause mortality (OR: 0.67, 95% CI: 0.52, 0.86) compared to BVP. Conclusion: LBBAP was associated with improved ventricular electrical synchrony compared to BVP, as well as better echocardiographic and clinical outcomes. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Multiple methods are used to tackle ipsilateral obstructed venous access in patients undergoing a device upgrade by implanting a new left ventricular lead. One feasible solution to tackle this is implantation of the upgrade lead contralaterally with pre‐sternal tunnelization to the opposite side under conscious sedation. [ABSTRACT FROM AUTHOR]

Introduction: Successful implantations of the Aveir VR, have been effectively demonstrated in adults; however, there remain limited reports supporting safe and feasible implantation of the Aveir VR in the young population. Methods: Retrospective, observational study of Aveir VR implantation of young patients (≦21 years old) at UC Davis Medical Center from November 2022 to January 2024 via the internal jugular or femoral vein implantation approaches. Indications for pacing, patient demographics, pacing thresholds and longevity were reported at the time of implantation and last follow‐up. Results: A total of 10 patients received the Aveir VR with a median age of years (IQR 12.5–17) and median weight of 50.8 kg (IQR 44.6–60.9) kg. The majority were male (80%). Aveir VR leadless pacemaker occurred via internal jugular venous (90%) or femoral venous (10%) approaches. Indications for placement were intermittent complete heart block (60%) and sinus pauses (40%). Adequate impedance, sensing and thresholds were maintained from implantation to a median follow‐up of 9 months. Predicted pacemaker longevity at follow‐up median was 23.8 years. There were no complications in any of the 10 patients. Conclusion: Aveir VR implantation via the internal jugular and femoral veins is feasible in the young patient population with stable pacing parameters at follow‐up. [ABSTRACT FROM AUTHOR]

Introduction: Rheumatic heart disease with persistent atrial fibrillation (RHD‐AF) is associated with increased morbidity. However, there is no standardized approach for the maintenance of sinus rhythm (SR) in them. We aimed to determine the utility of a stepwise approach to achieve SR in RHD‐AF. Methods: Consecutive patients with RHD‐AF from July 2021 to August 2023 formed the study cohort. The stepwise approach included pharmacological rhythm control and/or electrical cardioversion (Central illustration). In patients with recurrence, additional options included AF ablation or pace and ablate strategy with conduction system pacing or biventricular pacing. Clinical improvement, NT‐proBNP, 6‐Minute Walk Test (6MWT), heart failure (HF) hospitalizations, and thromboembolic complications were documented during follow‐up. Results: Eighty‐three patients with RHD‐AF (mean age 56.13 ± 9.51 years, women 72.28%) were included. Utilizing this approach, 43 (51.81%) achieved and maintained SR during the study period of 11.04 ± 7.14 months. These patients had improved functional class, lower NT‐proBNP, better distance covered for 6MWT, and reduced HF hospitalizations. The duration of AF was shorter in patients who achieved SR, compared to those who remained in AF (3.15 ± 1.29 vs 6.93 ± 5.23, p = 0.041). Thirty‐five percent (29) maintained SR after a single cardioversion over the study period. Only one underwent AF ablation. Of the 24 who underwent pace and ablate strategy, atrial lead was implanted in 22 (hybrid approach), and 50% of these achieved and maintained SR. Among these 24, none had HF hospitalizations, but patients who maintained SR had further improvement in clinical and functional parameters. Conclusions: RHD‐AF patients who could achieve SR with a stepwise approach, had better clinical outcomes and lower HF hospitalizations. [ABSTRACT FROM AUTHOR]

Background: Identification of infrequent nonpulmonary vein trigger premature atrial contractions (PACs) is challenging. We hypothesized that pace mapping (PM) assessed by correlation scores calculated by an intracardiac pattern matching (ICPM) module was useful for locating PAC origins, and conducted a validation study to assess the accuracy of ICPM‐guided PM. Methods: Analyzed were 30 patients with atrial fibrillation. After pulmonary vein isolation, atrial pacing was performed at one or two of four sites on the anterior and posterior aspects of the left atrium (LA, n = 10/10), LA septum (n = 10), and lateral RA (n = 10), which was arbitrarily determined as PAC. The intracardiac activation obtained from each pacing was set as an ICPM reference consisting of six CS unipolar electrograms (CS group) or six CS unipolar electrograms and four RA electrograms (CS–RA group). Results: The PM was performed at 193 ± 107 sites for each reference pacing site. All reference pacing sites corresponded to sites where the maximal ICPM correlation score was obtained. Sites with a correlation score ≥98% were rarely obtained in the CS‐RA than CS group (33% vs. 55%, P =.04), but those ≥95% were similarly obtained between the two groups (93% vs. 88%, P =.71), and those ≥90% were obtained in all. The surface areas with correlation scores ≥98% (0[0,10] vs. 10[0,35] mm2, P =.02), ≥95% (10[10,30] vs. 50[10,180] mm2, P =.002) and ≥90% (60[30,100] vs. 170[100,560] mm2, P =.0002) were smaller in the CS‐RA than CS group. Conclusions: ICPM‐guided PM was useful for identifying the reference pacing sites. Combined use of RA and CS electrograms may improve the mapping quality. [ABSTRACT FROM AUTHOR]

Objective: This study evaluates the feasibility and efficacy of implanting a leadless pacemaker at the right atrial appendage (RAA) in a preclinical minipig model, aiming to address the limitations of atrial pacing with current leadless devices like the Medtronic Micra, which is typically used for right ventricular implantation. Methods: Four minipigs, each with a median body weight of 45.8 ± 10.0 kg, underwent placement of the Micra transcatheter pacing system (TPS) via the right femoral vein into the RAA apex. The pacing performance was assessed over 1‐week (short‐term) and 3‐month (long‐term) periods. Outcomes: The initial findings indicated successful implantation, with satisfactory intrinsic R‐wave amplitudes and pacing threshold. In the following period, the sensitivity, threshold, and impedance were stable with time. Notably, upon explanation at 3 months, a deep myocardial penetration by the device was observed, necessitating a redesign for safe long‐term use in a growing subject's heart. Conclusion: While initial results suggest that RAA apex placement of the Micra TPS is promising for potential inclusion in a dual‐chamber pacing system, the issue of myocardial penetration highlights the need for device redesign to ensure safety and effectiveness in long‐term applications. [ABSTRACT FROM AUTHOR]

An 80‐years‐old patient with permanent atrial fibrillation and symptomatic, paroxysmal atrioventricular blocks (AVBs) underwent leadless pacemaker (L‐PM) implantation. Seven years after implantation, as a consequence of a progression of the AVB towards a persistent form, resulting in an increased need for pacing, he developed a pacing‐induced cardiomyopathy. He then underwent a successful upgrade from L‐PM to a transvenous pacemaker (T‐PM) with left bundle branch area pacing (LBBAP). The L‐PM did not interfere with the T‐PM and was turned off and abandoned. One month after the upgrading the patient showed a significant improvement in cardiac function and functional capacity. [ABSTRACT FROM AUTHOR]

Background: There is limited research on the intra‐individual efficacy of ventricular pacing minimization algorithms developed by Biotronik—the Ventricular Pace Suppression algorithm (VpS) and the Intrinsic Rhythm Support plus algorithm (IRSplus) (BIOTRONIK SE & Co. KG, Berlin, Germany). We performed a randomized pilot trial that evaluated the efficacy of two algorithms in patients with symptomatic sinus node dysfunction (SND) who received a dual‐chamber pacemaker. Methods: The trial was conducted in 11 tertiary hospitals in South Korea. The patients were randomized to either the VpS or IRSplus algorithm group after a 3‐month period of fixed atrioventricular (AV) delay. The primary outcome was the ventricular pacing percentage (Vp%) at each follow‐up visit. The secondary outcomes were the occurrence of heart failure (HF) and atrial fibrillation (AF) during the study period. Results: Data from 131 patients were analyzed. Initially, their average Vp% over 3 months with a fixed AV interval was 14.1 ± 19.4%. Patients were randomly assigned to VpS and IRSplus groups, with 66 and 65 in each. Algorithms reduced average Vp% to 4.0 ± 11.3% at 9 months and 6.7 ± 14.9% at 15 months. These algorithms were more effective for patients with paced AV delay (PAVD) ≤300 ms compared to those with PAVD >300 ms. Both algorithms were equally effective in reducing Vp%. Clinical AF or HF hospitalization was not observed during the study period. Conclusion: The VpS and IRSplus algorithms are effective and safe in minimizing unnecessary ventricular pacing in patients with SND. [ABSTRACT FROM AUTHOR]

Introduction: Cardiovascular and noncardiovascular comorbidities have been recognized as predictors of clinical response in patients receiving cardiac resynchronization therapy (CRT). However, data on vitamin D as a predictor of CRT response are conflicting. Method: We identified studies from MEDLINE and Embase databases, searching from inception to May 2024, to investigate the association between 25‐OH vitamin D levels before CRT implantation and outcomes. Studies had to report 25‐OH vitamin D levels or the proportion of patients with vitamin D insufficiency and categorize outcomes as CRT responders or nonresponders. We extracted mean 25‐OH vitamin D and standard deviations for both groups from each study and calculated the pooled mean difference (MD). We also retrieved risk ratios, and 95% confidence intervals (CIs) for the association between vitamin D insufficiency and lack of CRT response, combining them using the generic inverse variance method. Results: Our meta‐analysis included four studies. CRT responders had higher levels of 25‐OH vitamin D than nonresponders, with a pooled MD of 8.04 ng/mL (95% CI: 3.16–12.93; I2 = 48%, p <.001). Patients with vitamin D insufficiency before implantation had higher odds of lacking response to CRT, with a pooled RR of 3.28 (95% CI: 1.43–7.50; I2 = 0%, p =.005) compared to those with normal vitamin D. Conclusions: CRT responders had higher 25‐OH vitamin D levels compared to nonresponders. Vitamin D insufficiency was associated with a higher risk of nonresponse to CRT. These findings highlight the importance of monitoring and managing vitamin D levels in these patients. [ABSTRACT FROM AUTHOR]

A rotational activation pattern (RAP) around the localized line of a conduction block often correlates with sites specific to the critical zones of ventricular tachycardia (VT). The wavefront direction during substrate mapping affects manifestation of the RAP and line of block. The purpose of this study was to investigate the most optimal cardiac rhythm for identifying RAP and line of block in substrate mapping. We retrospectively evaluated 71 maps (median 3205 points/map) in 46 patients (65 ± 15 years; 33% with ischemic cardiomyopathy) who underwent high-density substrate mapping and ablation of scar-related VT. Appearance of a RAP during sinus, right ventricular (RV)-paced, left ventricular (LV)-paced, and biventricular-paced rhythms was investigated. RAP was identified in 24 of 71 maps (34%) in the region where wavefronts from a single direction reached but not in the region where wavefronts from multiple directions centripetally collided. The probability of identifying the RAP depended on scar location; that is, anteroseptal and inferoseptal, inferior and apical, and basal lateral RAPs were likely to be identified during sinus/atrial, RV-paced, and LV-paced rhythms, respectively. In 13 patients, the RAP was not evident in the baseline map but became apparent during remapping in the other rhythm, in which the wavefront reached the site earlier within the entire activation time. The optimal rhythm for substrate mapping depends on the spatial distribution of the area of interest. A paced rhythm with pacing sites near the scar may facilitate the identification of critical VT zones. [ABSTRACT FROM AUTHOR]

Aims: The trials upon which recommendations for the use of cardiac resynchronization therapy (CRT) in heart failure used optimal medical therapy (OMT) before sodium‐glucose co‐transporter 2 inhibitors (SGLT2i). Moreover, the SGLT2i heart failure trials included only a small proportion of participants with CRT, and therefore, it remains uncertain whether SGLT2i should be considered part of OMT prior to CRT. Methods and results: We compared electrocardiogram (ECG) and echocardiographic responses to CRT as well as hospitalization and mortality rates in consecutive patients undergoing implantation at a large tertiary centre between January 2019 to June 2022 with and without SGLT2i treatment. Three hundred seventy‐four participants were included aged 74.0 ± 11.5 years (mean ± standard deviation), with a left ventricular ejection fraction (LVEF) of 31.8 ± 9.9% and QRS duration of 161 ± 29 ms. The majority had non‐ischaemic cardiomyopathy (58%) and were in NYHA Class II/III (83.6%). These characteristics were similar between patients with (n = 66) and without (n = 308) prior SGLT2i treatment. Both groups demonstrated similar evidence of response to CRT in terms of QRS duration shortening, and improvements in LVEF, left ventricular end‐diastolic inner‐dimension (LVIDd) and diastolic function (E/A and e/e′). While there was no difference in rates of hospitalization (for heart failure or overall), mortality was significantly lower in patients treated with SGLT2i compared with those who were not (6.5 vs. 16.6%, P = 0.049). Conclusions: We observed an improvement in mortality in patients undergoing CRT prescribed SGLT2i compared with those not prescribed SGLT2i, despite similar degrees of reverse remodelling. The authors recommend starting SGLT2i prior to CRT implantation, where it does not delay implantation. [ABSTRACT FROM AUTHOR]

Aims: Despite half of all heart failure patients suffering from heart failure with preserved ejection fraction (HFpEF), treatment options are limited. This study aims to compare safety and efficacy of standard pacemaker programming (DDD or DDDR) and a novel pacing algorithm PressurePace™ (BaroPace Inc, Issaquah, WA, USA) which modulates atrial pacing rate based on blood pressure (BPAP). Methods: This prospective, randomized, double‐blind, non‐significant risk proof of concept study was conducted at two large cardiology clinics in Los Angeles, California, USA. Subjects underwent two modified Bruce protocol graded treadmill exercise tests in which pacemaker programming was randomized to either standard programming (DDD or DDDR), or BPAP at least 1 week apart. Physiological measurements of heart rate (HR), and systolic and diastolic blood pressure (BP) were collected at 2 min intervals. During the BPAP treadmill test, the pacemaker activity sensor was disabled. The PressurePace algorithm instructed the pacemaker technician to modify or leave unchanged the atrial pacing rate based on these BP measurements. Subjects and clinical staff were blinded to pacemaker programming, only the pacemaker technician was unblinded. Results: Ten subjects with HFpEF associated with hypertension who also had permanent dual‐chamber pacemakers, previously implanted for standard clinical indications, participated in the study. Mean age was 70.1 ± 6.8 years, left ventricular ejection fraction of 54.8 ± 1.9%. Exercise duration increased in all 10 subjects, when paced in the BPAP mode compared with standard pacemaker programming, showing a mean increase of 117 s (26%, P = 0.0016). The algorithm could adjust HR at each 2 min interval. The majority of subjects (60%) had their atrial pacing rate increased an average of 20% at t = 2 min. In the remaining 40% of subjects, the algorithm instructed HR to be unchanged. In two subjects, the pacing rate was not increased until t = 6 min. In contrast, subjects programmed to DDDR experienced an average of 45% increase in atrial pacing rate at t = 2 min. In the post‐treadmill recovery period, SBP was higher for subjects who underwent BPAP. This difference in SBP was most pronounced immediately post‐treadmill and diminished as subjects progressed through the 30 min recovery period. Statistical significance was achieved at t = 0, 20, and 30 min post‐treadmill. Conclusions: An increase in exercise duration was reported in HFpEF subjects using a pacing algorithm that modulated HR based on BP compared with standard programming. These encouraging results form the basis for a larger, randomized cross‐over trial to confirm these initial observations, further characterize the safety, efficacy, and possible mechanisms of action in both acute and longer‐term treatment. [ABSTRACT FROM AUTHOR]

Aims: Cardiac resynchronization therapy (CRT) is an established treatment for drug‐refractory heart failure (HF) in patients with left bundle branch block (LBBB). Acute haemodynamic improvement after CRT implantation may enable the intensification of HF medication soon thereafter. Immediate pharmacotherapy intensification (IPI) after CRT implantation achieves a synergetic effect, possibly leading to a better prognosis. This study aimed to explore the incidence, characteristics, and impact of IPI on real‐world outcomes among CRT recipients with a history of hospitalization for acute HF. Methods and results: This multicentre retrospective study enrolled CRT recipients with LBBB morphology, a QRS width ≥120 ms, a left ventricular ejection fraction ≤35%, and New York Heart Association II–IV HF symptoms. All patients had previous HF hospitalizations within the previous year and received guideline‐directed medical therapy before CRT implantation. Patient baseline characteristics, including HF medication, were collected. IPI was defined as the intensification of beta‐blockers, angiotensin‐converting enzyme inhibitors, angiotensin receptor blockers, and mineralocorticoid receptor antagonists within 30 days of CRT implantation. The primary endpoint was all‐cause death or first hospitalization for HF; the secondary endpoint was all‐cause death. We enrolled 194 patients (75% male; mean age, 65 ± 13 years; 78% with non‐ischaemic cardiomyopathy). One hundred five (54%) patients received IPI. Patients who received IPI exhibited a significantly shorter QRS duration (159 ± 26 vs. 171 ± 32 ms; P = 0.004), higher estimated glomerular filtration rate (55.2 ± 20.0 vs. 47.8 ± 24.7 mL/min/1.73 m2; P = 0.022), and more dilated cardiomyopathy. During a median follow‐up period of 29 months, 70 (36%) patients reached the primary endpoint and 42 (22%) patients died. Patients with IPI showed significantly better outcomes for the primary and secondary endpoints than patients without IPI. The volumetric responder ratio at 6 months after implantation was not significantly different between patients with and without IPI; however, patients who received IPI had reduced mortality even at 6 months after implantation. In the multivariate analysis, IPI was an independent predictor of the primary endpoint (hazard ratio, 0.51; 95% confidence interval, 0.27–0.97; P = 0.043). Conclusions: Immediate intensification of HF medication was achieved in 54% of CRT recipients and was significantly higher in patients without excessive QRS prolongation, preserved renal function, and dilated cardiomyopathy than others. In patients with LBBB morphology and QRS ≥ 120 ms, IPI was associated with a significantly better prognosis and fewer HF hospitalizations after CRT implantation than others. [ABSTRACT FROM AUTHOR]

Background: 123I-meta-iodobenzylguanidine (mIBG) has been applied to patients with chronic heart failure (CHF). However, the relationship between 123I-mIBG activity and lethal arrhythmic events (ArE) is not well defined. This study aimed to determine this relationship in Japanese and European cohorts. Results: We calculated heart-to-mediastinum (H/M) count ratios and washout rates (WRs) of 827 patients using planar 123I-mIBG imaging. We defined ArEs as sudden cardiac death, arrhythmic death, and potentially lethal events such as sustained ventricular tachycardia, cardiac arrest with resuscitation, and appropriate implantable cardioverter defibrillator (ICD) discharge, either from a single ICD or as part of a cardiac resynchronization therapy device (CRTD). We analyzed the incidence of ArE with respect to H/M ratios, WRs and New York Heart Association (NYHA) functional classes among Japanese (J; n = 581) and European (E; n = 246) cohorts. We also simulated ArE rates versus H/M ratios under specific conditions using a machine-learning model incorporating 13 clinical variables. Consecutive patients with CHF were selected in group J, whereas group E comprised candidates for cardiac electronic devices. Groups J and E mostly comprised patients with NYHA functional classes I/II (95%) and II/III (91%), respectively, and 21% and 72% were respectively implanted with ICD/CRTD devices. The ArE rate increased with lower H/M ratios in group J, but the relationship was bell-shaped, with a high ArE rate within the intermediate H/M range, in group E. This bell-shaped curve was also evident in patients with NYHA classes II/III in the combined J and E groups, particularly in those with a high (> 15%) mIBG WR and with ischemic, but not in those with non-ischemic etiologies. Machine learning-based prediction of ArE risk aligned with these findings, indicating a bell-shaped curve in NYHA class II/III but not in class I. Conclusions: The relationship between cardiac 123I-mIBG activity and lethal arrhythmic events is influenced by the background of patients. The bell-shaped relationship in NYHA classes II/III, high WR, and ischemic etiology likely aids in identifying patients at high risk for ArEs. [ABSTRACT FROM AUTHOR]

Aims Methods and results Conclusions The randomized, double‐blind, placebo‐controlled HOPE‐HF trial assessed the benefit of atrio‐ventricular (AV) delay optimization delivered using His bundle pacing. It recruited patients with left ventricular ejection fraction ≤40%, PR interval ≥200 ms, and baseline QRS ≤140 ms or right bundle branch block. Overall, there was no significant increase in peak oxygen uptake (VO2max) but there was significant improvement in heart failure specific quality of life. In this pre‐specified secondary analysis, we evaluated the impact of baseline PR interval, echocardiographic E‐A fusion, and the magnitude of acute high‐precision haemodynamic response to pacing, on outcomes.All 167 randomized participants underwent measurement of PR interval, acute haemodynamic response at optimized AV delay, and assessment of presence of E‐A fusion. We tested the impact of these baseline parameters using a Bayesian ordinal model on VO2max, quality of life and activity measures. There was strong evidence of a beneficial interaction between the baseline acute haemodynamic response and the blinded benefit of pacing for VO2 (Pr 99.9%), Minnesota Living With Heart Failure (MLWHF) (Pr 99.8%), MLWHF physical limitation score (Pr 98.9%), EQ‐5D visual analogue scale (Pr 99.6%), and exercise time (Pr 99.4%). The baseline PR interval and the presence of baseline E‐A fusion did not have this reliable ability to predict the clinical benefit of pacing over placebo across multiple endpoints.In the HOPE‐HF trial, the acute haemodynamic response to pacing reliably identified patients who obtained clinical benefit. Patients with a long PR interval (≥200 ms) and left ventricular impairment who obtained acute haemodynamic improvement with AV‐optimized His bundle pacing were likely to obtain clinical benefit, consistent across multiple endpoints. Importantly, this gradation can be reliably tested for before randomization, but does require high‐precision AV‐optimized haemodynamic assessment to be performed. [ABSTRACT FROM AUTHOR]

Aims Methods and results Conclusions The primary aim was to evaluate the effect of dapagliflozin according to QRS duration across the spectrum of left ventricular ejection fraction (LVEF), given that prolongation of QRS duration is associated with less favourable ventricular remodelling with pharmacological therapy and worse outcomes.A pooled analysis of the DAPA‐HF and DELIVER trials, excluding patients with a paced rhythm and cardiac resynchronization therapy. Overall, 4008 patients had heart failure (HF) with reduced ejection fraction (HFrEF), and 5816 had HF with mildly reduced/preserved ejection fraction (HFmrEF/HFpEF). QRS duration was <120 ms in 7039 patients (71.7%), 120–149 ms in 1725 (17.6%), and ≥150 ms in 1060 patients (10.8%). The median follow‐up time was 23 months. The rate of the primary composite outcome of cardiovascular death or worsening HF was 9.2 (95% confidence interval [CI] 8.7–9.7), 14.3 (13.0–15.7), and 15.9 (14.1–17.9) per 100 patient‐years in the <120, 120–149, and ≥150 ms groups, respectively. This gradient in event rates was observed both in HFrEF and HFmrEF/HFpEF. Dapagliflozin, compared with placebo, reduced the risk of the primary outcome consistently across the QRS duration subgroups (hazard ratio [95% CI] 0.75 [0.67–0.85], 0.79 [0.65–0.96], and 0.89 [0.70–1.13] in the <120, 120–149, and ≥150 ms groups, respectively; p for interaction = 0.28). The effect of dapagliflozin on the primary outcome was consistent across the QRS duration regardless of HF phenotype that is, HFrEF or HFmrEF/HFpEF.Prolongation of QRS duration is associated with worse outcomes irrespective of HF phenotype. Dapagliflozin reduced the risk of the primary outcome, regardless of QRS duration, in DAPA‐HF and DELIVER. [ABSTRACT FROM AUTHOR]

Objective: To construct a nomogram for predicting the responsiveness of cardiac resynchronization therapy (CRT) in patients with chronic heart failure and verify its predictive efficacy. Method: A retrospective study was conducted including 109 patients with chronic heart failure who successfully received CRT from January 2018 to December 2022. According to patients after six months of the CRT preoperative improving acuity in the left ventricular ejection fraction is 5% or at least improve grade 1 NYHA heart function classification, divided into responsive group and non-responsive group. Clinical data of patients were collected, and LASSO regression analysis and multivariate logistic regression analysis were used to explore relative factors. A nomogram was constructed, and the predictive performance of the nomogram was evaluated using the calibration curve and decision curve analysis (DCA). Results: Among the 109 patients, 61 were assigned to the CRT-responsive group, while 48 were assigned to the non-responsive group. LASSO regression analysis showed that left ventricular end-systolic volume, diffuse fibrosis, and left bundle branch block (LBBB) were independent factors for CRT responsiveness in patients with heart failure (P < 0.05). Based on the above three predictive factors, a nomogram was constructed. The ROC curve analysis showed that the area under the curve (AUC) was 0.865 (95% CI 0.794–0.935). The calibration curve analysis showed that the predicted probability of the nomogram is consistent with the actual occurrence rate. DCA showed that the line graph model has an excellent clinical net benefit rate. Conclusion: The nomogram constructed based on clinical features, laboratory, and imaging examinations in this study has high discrimination and calibration in predicting CRT responsiveness in patients with chronic heart failure. [ABSTRACT FROM AUTHOR]

Background: Right ventricular (RV) failure is an important predicting factor regarding overall and event-free survival regardless of baseline left ventricular (LV) function in patients with severe heart failure (HF). Previous studies have indicated that cardiac resynchronization therapy (CRT) improves LV and RV reverse remodeling in patients with systolic dyssynchrony within the left ventricle. However, there is conflicting evidence regarding the role of CRT in RV function. The aim of this systematic review and meta-analysis was to examine the implications of CRT on RV function indices. Methods: A systematic literature search was conducted using the MedLine and EMBASE databases and the Cochrane Library from their inception until 18 March 2024. Eligible were studies providing information on RV function indices, both at baseline and after CRT. Evidence was summarized using random-effects meta-analytic models. Results: In total, 30 studies were deemed eligible. CRT resulted in a significant improvement in right ventricular fractional area change (mean difference (MD) 5.11%, 95% confidence interval (CI) 2.83 to 7.39), tricuspid annular plane systolic excursion (TAPSE, MD 1.63 mm, 95% CI 1.10 to 2.16), and myocardial systolic excursion velocity (MD 1.85 cm/s, 95% CI 1.24 to 2.47) as well as a significant decrease in pulmonary artery systolic pressure (MD −6.24 mmHg, 95% CI −8.32 to −4.16). A non-significant effect was observed on TAPSE to PASP ratio and right ventricular global longitudinal strain. Conclusions: Our meta-analysis demonstrates that CRT is associated with a significant improvement in echocardiographic parameters of RV function. Further investigation is necessary to elucidate how these changes, both independently and in conjunction with LV improvement, impact patients' long-term prognosis, and to identify the specific patient populations expected to derive the greatest benefit. [ABSTRACT FROM AUTHOR]

Key Points: Question: Cardiac arrest frequently occurs without explanation, even after a thorough clinical evaluation. Can a simple maneuver clinically diagnose calcium release deficiency syndrome (CRDS), a newly described cause of sudden death? Findings: In this international, multicenter, case-control study, a provoked measure of T-wave amplitude on an electrocardiogram ascertained cases of CRDS with high accuracy. The genetic mouse models recapitulated the human findings and suggested a pathologically large systolic calcium release from the sarcoplasmic reticulum was responsible. Meaning: These preliminary results suggest that the repolarization response on an electrocardiogram to brief tachycardia followed by a pause may effectively diagnose CRDS. Given the frequency of unexplained cardiac arrest, should these findings be confirmed in larger studies, this readily available maneuver may provide clinically actionable information. Importance: Sudden death and cardiac arrest frequently occur without explanation, even after a thorough clinical evaluation. Calcium release deficiency syndrome (CRDS), a life-threatening genetic arrhythmia syndrome, is undetectable with standard testing and leads to unexplained cardiac arrest. Objective: To explore the cardiac repolarization response on an electrocardiogram after brief tachycardia and a pause as a clinical diagnostic test for CRDS. Design, Setting, and Participants: An international, multicenter, case-control study including individual cases of CRDS, 3 patient control groups (individuals with suspected supraventricular tachycardia; survivors of unexplained cardiac arrest [UCA]; and individuals with genotype-positive catecholaminergic polymorphic ventricular tachycardia [CPVT]), and genetic mouse models (CRDS, wild type, and CPVT were used to define the cellular mechanism) conducted at 10 centers in 7 countries. Patient tracings were recorded between June 2005 and December 2023, and the analyses were performed from April 2023 to December 2023. Intervention: Brief tachycardia and a subsequent pause (either spontaneous or mediated through cardiac pacing). Main Outcomes and Measures: Change in QT interval and change in T-wave amplitude (defined as the difference between their absolute values on the postpause sinus beat and the last beat prior to tachycardia). Results: Among 10 case patients with CRDS, 45 control patients with suspected supraventricular tachycardia, 10 control patients who experienced UCA, and 3 control patients with genotype-positive CPVT, the median change in T-wave amplitude on the postpause sinus beat (after brief ventricular tachycardia at ≥150 beats/min) was higher in patients with CRDS (P <.001). The smallest change in T-wave amplitude was 0.250 mV for a CRDS case patient compared with the largest change in T-wave amplitude of 0.160 mV for a control patient, indicating 100% discrimination. Although the median change in QT interval was longer in CRDS cases (P =.002), an overlap between the cases and controls was present. The genetic mouse models recapitulated the findings observed in humans and suggested the repolarization response was secondary to a pathologically large systolic release of calcium from the sarcoplasmic reticulum. Conclusions and Relevance: There is a unique repolarization response on an electrocardiogram after provocation with brief tachycardia and a subsequent pause in CRDS cases and mouse models, which is absent from the controls. If these findings are confirmed in larger studies, this easy to perform maneuver may serve as an effective clinical diagnostic test for CRDS and become an important part of the evaluation of cardiac arrest. Case-control study including individual cases of calcium release deficiency syndrome (CRDS), 3 patient control groups, and genetic mouse models assesses the cardiac repolarization response on an electrocardiogram after brief tachycardia and a pause as a clinical diagnostic test for CRDS. [ABSTRACT FROM AUTHOR]

Objective To investigate the effect of left bundle branch area pacing (LBBaP) on new-onset atrial fibrillation (NOAF) and atrial high rate episodes (AHREs) in patients with atrioventricular block (AVB). Methods Eighty-four patients with III°AVB for pacemaker implantaion were divided into the LBBaP group (n =42) and the RVSP group (n = 42) based on the site of the ventricular leads. The two groupswere compared in terms of the pre- and post- operative QRSd, ventricular pacing parameters, complications, incidence of stroke, NOAF and AHREs. Results (1) The incidence of postoperative NOAF and AHREs in the LBBaP group was significantly lower compared with RVSP group (P < 0.05). (2) The p-QRSd in the LBBaP group was significantly shorter compared with RVSP group (P < 0.05). (3) The two groups showed no significant differences in ventricular pacing parameters, incidence of complications and stroke events(P > 0.05). Conclusion LBBaP is superior to right ventricular pacing in reducing the incidence of postoperative AHREs and NOAF in patients after implantation and improving the prognosis of patients. [ABSTRACT FROM AUTHOR]

This article provides an overview of recent studies on heart failure (HF) that may be of interest to HF specialists. One study explores the use of smartphone-based seismocardiography for HF screening, which showed promising results in accurately identifying symptomatic HF patients. Another study examines the use of mineralocorticoid receptor antagonists (MRAs) in patients with worsening kidney function, finding that MRAs can still be beneficial. Additionally, a study suggests that the current guidelines for implantable cardioverter-defibrillator (ICD) placement may need to be reconsidered based on the timing of left ventricular function recovery in de novo HF. Another document discusses three studies related to HF treatment, including the benefits of target doses of certain medications, the use of transcatheter mitral valve repair in patients with functional mitral regurgitation (FMR) and HF, and the effectiveness of sodium-glucose cotransporter 2 inhibitors (SGLT2i) in patients with transthyretin amyloid cardiomyopathy (ATTR-CM). While these findings are promising, further research is needed for confirmation. [Extracted from the article]