Adults with congenital heart disease increasingly survive into later adulthood, exposing the long-term limitations of a morphologic right ventricle supporting the systemic circulation. Heart failure and arrhythmias are common, frequently coexist, and represent leading causes of morbidity and mortality in this population. This review examines the mechanisms linking systemic right ventricular dysfunction and arrhythmogenesis and their implications for contemporary management. Recent literature highlights that chronic systemic loading of the right ventricle promotes maladaptive structural, electrical, and inflammatory remodeling, creating a substrate for atrial and ventricular arrhythmias. Conversely, arrhythmias exacerbate systemic right ventricular dysfunction through loss of atrioventricular synchrony, tachycardia-mediated impairment, dyssynchrony, and hypoxemia, mechanisms to which systemic right ventricular physiologies are particularly susceptible. Advances in catheter ablation, device therapy, cardiac resynchronization, and conduction system pacing have expanded therapeutic options, although evidence guiding patient selection and timing remains limited. Failure of the systemic right ventricle and arrhythmias are tightly interwoven processes that evolve over time. Integrating mechanistic insights with longitudinal imaging, electrophysiologic phenotyping, and individualized risk assessment may improve arrhythmia management, refine device strategies, and support more personalized approaches to preserving systemic right ventricular function.

Severe mitral regurgitation (MR) is associated with an unfavourable prognosis, characterized by high mortality and reduced quality of life. Mitral surgery remains the gold standard for degenerative MR in patients with low operative risk, ensuring durability and improved survival; however, in elderly or frail patients, perioperative risk limits the applicability of surgical treatment. In this context, transcatheter edge-to-edge repair (TEER), predominantly with MitraClip™, has assumed an increasingly important role. The 2025 ESC/EACTS Guidelines recommend TEER in patients with severe secondary MR who remain symptomatic despite optimized medical therapy and cardiac resynchronization, with evidence demonstrating reduced hospitalizations and improved quality of life. Randomized trials such as COAPT and RESHAPE-HF2 have consolidated these findings, while the MATTERHORN study has shown non-inferiority of TEER compared with surgery in terms of clinical efficacy, with a superior safety profile. In primary MR, ongoing studies (REPAIR-MR, MITRA-HR) are evaluating the effectiveness of TEER vs. surgery in patients at moderate or high surgical risk. In summary, MitraClip currently represents the preferred therapeutic option in patients with high-risk secondary MR, while surgery remains indicated for repairable primary MR in low-risk surgical candidates.

The safety and tolerability of early invasive therapies for rapid atrial fibrillation in patients with cardiogenic shock is yet to be established. This retrospective study reviewed patients with diagnosis of atrial fibrillation and cardiogenic shock during the same hospital admission between 2019 and 2024. These patients were dependent on inotropes and/or mechanical circulatory support and received PVI or AVJ ablation with CRT implantation during the index hospitalization. Outcomes measured were procedural complications, post-procedural heart failure or Afib hospitalization, continued inotrope and/or mechanical circulatory dependence, mortality, and change in ejection fraction. Of 54 patients reviewed, 16 met the study criteria. At baseline, 94% (15/16) of patients were on inotropes for management of cardiogenic shock while 44% (7/16) were on mechanical circulatory support. There were minimal adverse events associated with invasive management of atrial fibrillation. There was a trend towards reduced dependence on inotropes and mechanical support post-procedure. There was a significant increase in ejection fraction from a baseline of 20% pre-procedure to an average of 36% post-procedure, with an increase in EF recorded in 80% of patients. There was one re-admission for heart failure and no re-admissions for atrial fibrillation at 6 months post-procedure. Our study shows that among patients with atrial fibrillation and cardiogenic shock, invasive therapy with pulmonary vein isolation or AV node ablation and CRT implantation is safe and may be associated with improved survival, reduced need for continued hemodynamic support, reduced hospital readmission, and improvement in left ventricular ejection fraction.

AimsGenerator longevity is the key issue for patients, and is also important for payers, yet implanters of Cardiac Implantable Electronic Devices (CIEDs) face a challenge when selecting the appropriate device since battery longevity is only known for previous generation devices and whilst projected longevities are available for current devices, these are not in comparable formats. This study presents a new framework that facilitates an estimation of longevities for all CIEDs of both previous and existing generations that could simplify personalization of the device choice.MethodsLongevity can be calculated based upon a simple concept entitled the “power consumption index” (PCI = t x I/C, where t is a constant of 1 hour, I is the current required by the device and C, its battery capacity). We retrieved published data from the user manuals of all commonly used pacemakers including single chamber, dual chamber, cardiac resynchronization and leadless devices. C and the components of current I including background current (Ibackground) and the pacing current (Ipacing) were calculated prior to calculation of the PCI for each device. Subsequently, a set of fictitious patient pool conditions via a Monte-Carlo simulation were used to model CIED survival curves which were then compared with real-life data from the Swedish device registry of previous generation CIEDs. Finally, we modeled survival curves for current generation devices using the PCI model.ResultsUsing the PCI approach we were able to calculate longevities for all pacemaker devices under a variety of settings. The modeled Ibackground matched the data reported by manufacturers, and, under a variety of settings, regression analysis showed a low average error rate between industry-reported and modelled longevities (ratio: modelled longevity/industry reported longevity −1) = 0.1 ± 4.0% and 0.1 ± 0.7% for previous and existing SR/DR devices, 1.0 ± 5.0% and 0 ± 3.0% for previous and existing CRT-P, and 0 ± 4.0% for leadless pacemakers, respectively).More than 50% of the PCI and thereby a significant contributor to longevity was accounted for by Ibackground. Ipacing was the second largest contributor (20% for standard single and dual chamber devices, 30% for CRT-P and 40% for leadless devices). Certain pacing algorithms and IEGM storage considerably impacted specific devices with longevity losses of up to 1 year. The Monte-Carlo analysis demonstrated consistency between projected longevities by the PCI model and real-life data for historical devices and the calculated longevities that stemmed from this were consistent with the real-world data from Sweden.ConclusionThe PCI model combining power consumption and battery capacity allows a comparison of longevity across CIEDs and programming options. Such a tool could help implanters improve personalization of device prescription for their patients and payers to make more informed decisions about tailoring device purchases and programming most appropriate for their population.

Generator longevity is the key issue for patients, and is also important for payers, yet implanters of Cardiac Implantable Electronic Devices (CIEDs) face a challenge when selecting the appropriate device since battery longevity is only known for previous generation devices and whilst projected longevities are available for current devices, these are not in comparable formats. This study presents a new framework that facilitates an estimation of longevities for all CIEDs of both previous and existing generations that could simplify personalization of the device choice. Longevity can be calculated based upon a simple concept entitled the "power consumption index" (PCI = t x I/C, where t is a constant of 1 hour, I is the current required by the device and C, its battery capacity). We retrieved published data from the user manuals of all commonly used pacemakers including single chamber, dual chamber, cardiac resynchronization and leadless devices. C and the components of current I including background current (Ibackground) and the pacing current (Ipacing) were calculated prior to calculation of the PCI for each device. Subsequently, a set of fictitious patient pool conditions via a Monte-Carlo simulation were used to model CIED survival curves which were then compared with real-life data from the Swedish device registry of previous generation CIEDs. Finally, we modeled survival curves for current generation devices using the PCI model. Using the PCI approach we were able to calculate longevities for all pacemaker devices under a variety of settings. The modeled Ibackground matched the data reported by manufacturers, and, under a variety of settings, regression analysis showed a low average error rate between industry-reported and modelled longevities (ratio: modelled longevity/industry reported longevity -1) = 0.1 ± 4.0% and 0.1 ± 0.7% for previous and existing SR/DR devices, 1.0 ± 5.0% and 0 ± 3.0% for previous and existing CRT-P, and 0 ± 4.0% for leadless pacemakers, respectively). More than 50% of the PCI and thereby a significant contributor to longevity was accounted for by Ibackground. Ipacing was the second largest contributor (20% for standard single and dual chamber devices, 30% for CRT-P and 40% for leadless devices). Certain pacing algorithms and IEGM storage considerably impacted specific devices with longevity losses of up to 1 year. The Monte-Carlo analysis demonstrated consistency between projected longevities by the PCI model and real-life data for historical devices and the calculated longevities that stemmed from this were consistent with the real-world data from Sweden. The PCI model combining power consumption and battery capacity allows a comparison of longevity across CIEDs and programming options. Such a tool could help implanters improve personalization of device prescription for their patients and payers to make more informed decisions about tailoring device purchases and programming most appropriate for their population.

The Clinical Consensus Statement of the European Society of Cardiology (ESC) updates expert opinions on conduction system pacing (CSP). It does not represent afocused update of the ESC pacemaker guidelines of 2021 since that would require the publication of new results of randomized trials. But an official statement became necessary because at the time of preparing the ESC guidelines on pacing and cardiac resynchronization, only very limited data on left bundle branch pacing were available rendering this form of pacing almost completely ignored in the recommendations. Second, daily implantation practice has changed substantially worldwide since the advent of CSP. Third, basically all international heart rhythm societies apart from the ESC have published new guidelines on the use CSP in 2023 which differ significantly from the European recommendations. The Clinical Consensus Statement on CSP of the ESC differs from the 2021 ESC guidelines only in nuances since ESC statutes do not allow that an ESC expert opinion paper substantially contradict current ESC guidelines. However, it is important for daily practice that CSP be recommended as apotential alternative to right ventricular pacing in patients with good left ventricular function or rare ventricular pacing is expected. Similarly, CSP is recommended as an alternative to biventricular pacing (BiVP) in reduced left ventricular function, in context with ablation of the atrioventricular node, in heart failure with wide QRS complex and for upgrading in pacing-induced cardiomyopathy. Finally, CSP is recommended in nonresponders to BiVP.

The use of guideline-directed medical therapy (GDMT) has substantially prolonged and improved the lives of patients with heart failure (HF). Nevertheless, adherence rates remain suboptimal. Even when successfully maximized and adhered to, there is a substantial residual risk of recurrent HF hospitalization and death. In light of this, there is a strong need for effective interventions that can decrease the high residual risk seen in patients with HF. Several device options exist that are approved by the US Food and Drug Administration and that have been shown to decrease morbidity and/or mortality in patients among whom GDMT is maximized. These strategies include valvular interventions (aortic valve replacement, mitral valve repair, and tricuspid valve repair or replacement), cardiac resynchronization, cardiac contractility modulation, remote hemodynamic monitoring, and baroreceptor activation therapy. The pivotal trials for each of these interventions, and the patient populations for which they have been approved, are discussed. Current rates of device use in clinical practice remain very low. For many device classes, the vast majority of eligible patients are not offered or prescribed the device. Several reasons may explain this mismatch, foremost of which is a lack of clinical awareness about when to escalate therapy, how to identify patients requiring more than GDMT, and access to centers with sufficient experience. To aid the appropriate uptake of device therapy in clinical practice, we propose a simple mnemonic for use by clinicians that can prompt the early identification and prompt referral of patients with HF who likely merit consideration of additional device-based therapy in addition to GDMT.

Assessment of left ventricular systolic function is essential for diagnosing and managing cardiac diseases and provides important prognostic information to the treating clinician. However, traditional methods for assessing left ventricular systolic function such as ejection fraction are limited by their reliance on geometric assumptions, subjective reader interpretation, sensitivity to loading conditions and volume, and reflection of a single plane of motion. In addition to interobserver and intraobserver variability and technical confounders, this evaluation is complicated by the complex 3-dimensional organization of the myocardial fibers, which are oriented longitudinally in the subendocardium, transversely in the midmyocardium, and obliquely in the subepicardium. Conversely, 2-dimensional speckle-tracking echocardiography measures left ventricular deformation as myocardial strain in the 3 planes of chamber motion: longitudinal, circumferential, and radial. From a clinical perspective, left ventricular global longitudinal strain offers superior diagnostic and prognostic value across the spectrum of cardiovascular disorders compared with ejection fraction, is highly reproducible, and detects subclinical dysfunction before the ejection fraction declines. Given the expanding clinical utility of speckle-tracking echocardiography and the incremental prognostic and therapeutic value of integrating global longitudinal strain into clinical practice as a potential biomarker, the objectives of this scientific statement are (1) to review the principles and technical aspects of speckle-tracking echocardiography strain imaging; (2) to provide a practical, evidence-based review of the application of speckle-tracking echocardiography in heart failure, cardiomyopathies, ischemic heart disease, valvular disease, and cardio-oncology; (3) to explore the potential utility of speckle-tracking echocardiography in cardiac resynchronization and implantable cardioverter defibrillator therapy; and (4) to outline the future directions of speckle-tracking echocardiography.

Currently, implantable automatic defibrillators (ICD) have demonstrated unobjectionable effectiveness in the primary and secondary prevention of sudden cardiac death (SCD) in the population of patients with high-risk heart diseases. However, its application is not free from complications. In response to this problem, the subcutaneous cardioverter defibrillator (S-ICD) emerged in 2009, a completely extracardiac and extrathoracic device, whose design has been optimized in recent years and which, despite its limitations, such as the absence of a pacemaker, has proven an efficacy not inferior to that of the conventional ICD, without the complications inherent to the procedure of handling it and the permanence of intravenous catheters. This makes the S-ICD a useful and effective option, being ideal for those patients who do not require anti-bradycardia or anti tachycardia cardiac stimulation or cardiac resynchronization.

LBBB is a totally a non-homogenous concept: defining 4 phenotypes of response to CRT in a highly experienced center

Working at the Hammersmith Hospital in London in the late 1980s, I recognized that patients with heart failure (HF) often deteriorated after pacemaker implantation. I even resorted to β1 partial agonists to manage bradycardia.1 Meanwhile, Derek Gibson had shown that shortening atrioventricular delay could reduce mitral regurgitation and improve ventricular filling in patients with dilated cardiomyopathy. As far back as 1971, he also described the benefits of biventricular pacing on ventricular synchrony.

Cardiac resynchronization in congenital heart disease.

The integrative physiology of the left ventricle and systemic circulation is fundamental to our understanding of advanced heart failure and cardiogenic shock. In simplest terms, any increase in aortic stiffness increases the vascular afterload presented to the failing left ventricle. The net effect is increased myocardial oxygen demand and reduced coronary perfusion pressure, thereby further deteriorating contractile function. Although mechanical circulatory support devices should theoretically work in concert with guideline-directed medical therapy, cardiac resynchronization and inotropic and vasopressor agents designed to support myocardial performance and enhance left ventricle recovery, this does not always occur. Each therapy and intervention may result in vastly different and sometimes deleterious effects on vascular afterload. Although best described by a combination of both steady-state and pulsatile components, the latter is frequently overlooked when mean arterial pressure or systemic vascular resistance alone is used to quantify vascular afterload in advanced heart failure and cardiogenic shock. In this state-of-the-art review, we examine what is known about vascular afterload in advanced heart failure and cardiogenic shock, including the use of temporary and permanent mechanical circulatory support systems. Importantly, we outline 4 key components for a more complete assessment of vascular afterload. Unlike previous discussions on this topic, we set aside considerations of venous return and ventricular preload, as important as they are, to focus exclusively on the hydraulic load within the systemic circulation against which the impaired left ventricle must contract.

Right ventricular (RV) pacing can impair left ventricular function and cause heart failure, known as pacing-induced cardiomyopathy (PICM). Upgrade to cardiac resynchronization (CRT) is its usual treatment; recently left bundle branch area pacing (LBBAP) has emerged as a potential alternative. Deep septal pacing (DSP), a simplified alternative to LBBAP, is still able to achieve narrower paced QRS than during conventional RV pacing. The aim of this study was to assess the effect of DSP in a cohort of patients with PICM. Consecutive patients diagnosed with PICM were included. The aim was to upgrade patients to DSP. The procedure was considered successful if a paced QRS duration ≤140ms was obtained, in the absence of a terminal R wave in V1. Twelve patients were included. The mean baseline LVEF was 33% (SD 4%), and the mean percentage of RV pacing was 99% (SD 1%). All patients had symptomatic heart failure. The mean paced QRS duration was 172ms (SD 14ms) with RV pacing, and 130ms (SD 7ms) with DSP (mean difference 42ms, p<0.001). At 6 months, the mean LVEF after the upgrade was 46% (SD 9%), significantly superior to LVEF with RV pacing (p = 0.001), a mean improvement of 13% (SD 10%). All patients except one experienced an improvement in LVEF of at least 5%. Our data suggest that DSP may be an effective and simpler alternative to biventricular or LBBAP in patients with PICM. Narrower paced QRS complexes can be achieved, which may lead to an improvement in left ventricular function.

Abstract BackgroundSacubitril/valsartan (an angiotensin receptor‐neprilysin inhibitors [ARNI]) might improve atrial fibrillation (AF) condition, but its added value remains controversial.AimWe aimed to analyse the effect of ARNI on AF burden.MethodWe conducted a single‐centre, retrospective self‐controlled study in a tertiary centre. Data were retrieved from January 2019–January 2023. All cardiac resynchronisation therapy‐implantable cardioverter defibrillator (CRT‐D) carriers on ARNI were included if implantation had been at least 3 months before drug initiation. Proarrhythmic events, equal time length control (before ARNI initiation), and exposure (after ARNI initiation) periods were defined. Echocardiographic data were retrieved if they were up to 1 year old before ARNI initiation and if they were available 3 months to 1 year after initiation. AF burden was defined by frequency and median value of paroxysmal events and the overall variation in AF status was determined. Ethical approval was granted by the Ethics Committee of the Centro Hospitalar e Universitário de Coimbra (Reference no: PI OBS.SF.174‐2022) and the study conforms with the Declaration of Helsinki.ResultsSeventy‐two patients were included in the study (73.3% men). After ARNI, there was a reduction in New York Heart Association functional class ± standard deviation (2.00 ± 0.75 to 1.85 ± 0.61, p = 0.043) and an increase in left ventricular ejection fraction ± standard deviation (from 31.67% ± 9.28% vs 37.33% ± 14.49%, p = 0.027). Before ARNI initiation, 34 patients did not have AF, 19 had paroxysmal AF, 15 had permanent AF, and 2 had persistent AF. The total amount of AF episodes (91 vs 44, p = 0.808) and median paroxysmal episodes (among those with paroxysmal AF or no AF) (5 vs 3, p = 0.121) were numerically reduced after ARNI initiation, though variation was not statistically significant. No differences were found as well regarding ventricular arrhythmias or device therapies.ConclusionARNI did not significantly decrease the number of AF paroxysmal episodes or median number of paroxysmal events per patient. Even though ARNI may have a positive impact on AF burden of heart failure patients, larger studies are needed to provide unequivocal evidence.

Swiss national cardiac device registry: changing trends in pacemaker and ICD procedures over the last two decades

Left bundle branch area pacing in the setting of cardiac amyloidosis: a case series

PO-06-040 A RANDOMISED DOUBLE-BLINDED CROSS-OVER STUDY TO EVALUATE THE IMPROVEMENT OF LEFT VENTRICULAR SYSTOLIC FAILURE USING TARGETED LEFT VENTRICULAR ENDOCARDIAL LEAD PLACEMENT IN CARDIAC RESYNCHRONISATION (NCT02174289)

Conduction latency in left bundle branch pacing in heart failure patient

The subcutaneous implantable cardioverter defibrillator (S-ICD) was developed as an alternative to the traditional transvenous implantable cardioverter defibrillator (TV-ICD), aiming to provide easier implantation, simplified detection algorithm of malignant ventricular arrhythmias and prevention from placing components in the cardiovascular system. The S-ICD is implanted subcutaneously or intramuscularly with the generator placed in the left midaxillary line and the lead tunneled subcutaneously in the left para-sternal region. Preimplant electrocardiogram screening is recommended to prevent implantation in patients at high risk of T wave over-sensing. Currently, the S-ICD is unsuitable for patients requiring pacing or cardiac resynchronization. Since the beginning, the S-ICD underwent extensive preclinical investigation until the first prospective multicentre trial demonstrating high efficacy and safety led to market release. While earlier studies focused on younger patients with higher ejection fraction, more recent studies showed favorable outcomes even in patients with comorbidities similar to those typically observed in patients receiving TV-ICD. The development of second and third generation devices has contributed to reduce inappropriate shocks and overcome previous limitations. The aim of this paper is to review the evidence in the literature over the past decade supporting S-ICD as a valid alternative to TV-ICD in terms of safety and efficacy, highlighting the improvements in technology, as well as outcomes.