Search Results (529)

Background: Refractory ventricular fibrillation (RVF) is a life-threatening condition characterized by the persistence of ventricular fibrillation despite multiple defibrillation attempts. It represents a critical challenge in out-of-hospital cardiac arrest management, with poor survival outcomes and limited guidance from current resuscitation guidelines. In recent years, alternative defibrillation strategies (ADSs), including dual sequential external defibrillation (DSED) and vector change defibrillation (VCD), have emerged as potential interventions to improve defibrillation success and patient outcomes. However, their clinical utility remains debated due to heterogeneous evidence and limited high-quality data. Methods: This narrative review explores the current landscape of ADSs in patients with RVF. MEDLINE, Google Scholar, the World Health Organization, LitCovid NLM, EMBASE, CINAHL Plus, and the Cochrane Library were examined from their inception to April 2025. Results: The available literature is dominated by retrospective studies and case series, with only one randomized controlled trial (DOSE-VF). This trial demonstrated improved survival to hospital discharge with ADSs compared to standard defibrillation. DSED was associated with higher rates of return of spontaneous circulation and favorable neurological outcomes. However, subsequent meta-analyses have produced inconsistent results, largely due to the heterogeneity of the included studies. The absence of sex-, gender-, and ethnicity-specific analyses further limits the generalizability of the findings. In addition, practical barriers, such as equipment availability, pose significant challenges to implementation. Conclusions: ADSs represent a promising yet still-evolving approach to the management of RVF, with DSED showing the most consistent signal of benefit. Further high-quality research is required to enhance generalizability and generate more definitive, high-level evidence. Full article

Background/Objectives: Patients with normal sinus rhythms undergoing cardiac resynchronization therapy defibrillator (CRT-D) implantation may benefit from a novel two-lead CRT-D system (CRT-DX), which features an atrial sensing dipole integrated into the right ventricular lead. This single-arm, international, non-controlled investigation focused on the safety and clinical efficacy of CRT-DX devices in CRT-D candidates who do not require atrial pacing. Methods: Patients indicated for CRT-D implantation (resting heart rates > 40 bpm and ≥100 bpm during exercise, no second or higher-degree AV block, and no history of persistent or permanent atrial fibrillation) were enrolled across 21 sites in four European countries. The primary endpoint was the need for an additional RA lead implantation within 12 months. Secondary endpoints comprised any invasive re-intervention to the CRT-DX system or infection. Results: Among the 110 patients (mean age 62 years, 70% male), 60% had an underlying non-ischemic cardiac disease. During 12 months of follow-up, RA lead implantation was required in two patients for atrial undersensing or chronotropic incompetence (RA lead implantation-free rate: 98.2% (95% CI: 92.7–99.5%)). Atrial sensing amplitudes were stable (mean: 4.7 ± 1.7 mV), AV-synchrony was maintained at >99%, and the median percentage of biventricular pacing exceeded 98%. The left ventricular ejection fraction improved by an absolute 14.7%. Conclusions: Using simple, clinically applicable inclusion criteria, the two-lead CRT-DX system demonstrated a low rate of subsequent RA lead implantations (1.8%) and maintained adequate RA sensing amplitudes throughout the observation period. The two-lead CRT-DX concept appears to be a feasible alternative for patients with preserved chronotropic competence. Full article

Background/Objectives: Impaired kidney function significantly increases mortality in recipients of implantable cardioverter defibrillators (ICDs). However, in the landmark studies evaluating ICDs and cardiac resynchronization therapy with a defibrillator (CRT-D) for the treatment of heart failure (HF) with a reduced ejection fraction (HFrEF), patients with Chagas cardiomyopathy (CC) have been underrepresented. This study aimed to determine whether kidney dysfunction has the same negative impacts on patients with ICDs or CRT-Ds and CC. Methods: We prospectively followed patients with CC and left ventricular ejection fractions (LVEFs) of ≤40% who underwent ICD or CRT-D implantation and had at least one prior creatinine measurement. The primary outcome was the survival rate during follow-up. Variables with a p of <0.10 from the univariate analysis were selected for inclusion in the Cox regression model. Results: A total of 343 patients were enrolled, with a median follow-up duration of 777 days. The mean age was 60.2 (±11.2) years. Fifty percent of patients were observed to have a New York Heart Association (NYHA) functional class of III, and the median left ventricular ejection fraction (LVEF) was 27% (22–32). Overall mortality events occurred in 113 (32.9%) participants during follow-up. Although the estimated glomerular filtration rate (eGFR) was significantly associated with survival in the univariate analysis [HR 0.98 (CI 95% 0.98–0.99), p = 0.007], it did not retain significance in the multivariate model [HR 0.99 (0.98–1.00), p = 0.138], which was adjusted for age, gender, atrial fibrillation (AF), body mass index (BMI), and the use of digoxin, furosemide, anticoagulants, and LVEF. Conclusions: Unlike other cardiomyopathies, impaired eGFR was not an independent predictor of mortality in this cohort of CC patients undergoing ICD or CRT-D implantation, possibly due to the distinctive pathophysiological mechanisms of the disease. These findings suggest that clinicians should not be discouraged from recommending CIEDs in patients with CC and moderately impaired kidney function, although further studies are warranted to assess outcomes in those with advanced CKD. Full article

Background/Objectives: Left atrial function can be a tool for risk stratification for hypertrophic cardiomyopathy (HCM). Over the past decade, there has been growing interest in the application of strain analysis for earlier and more accurate prediction of cardiovascular disease prognosis. This study aimed to investigate the performance of left atrial strain analysis compared to conventional left atrial measures in predicting clinical outcomes in Asian patients with HCM. Methods and Results: This was a retrospective study involving 291 patients diagnosed with HCM between 2010 and 2017. Left atrial volumes were assessed using the method of discs in orthogonal plans at both end diastole and end systole. Left atrial (LA) strain was obtained using a post-hoc analysis with TOMTEC software. We tested the various left atrial parameters against outcomes of (1) heart failure hospitalization and (2) event-free survival from a composite of adverse events, including all-cause mortality, ventricular tachycardia (VT)/ventricular fibrillation (VF) events, appropriate device therapy if an implantable cardioverter defibrillator (ICD) was implanted, stroke, and heart failure hospitalization. The patients had a mean age of 59.0 ± 16.7 years with a male preponderance (71.2%). The cumulative event-free survival over a follow-up of 3.9 ± 2.7 years was 55.2% for patients with an abnormal LA strain versus 82.4% for patients without one (p < 0.001). Multivariable Cox regression analyses were performed separately for each LA parameter, adjusting for age, sex, LV mass index, LV ejection fraction (EF), E/e’, the presence of LV outflow tract (LVOT) obstruction at rest, and atrial fibrillation. An analysis showed that all parameters except for LAEF demonstrated an independent association with heart failure hospitalization. Left atrial strain outperformed the rest of the parameters by demonstrating an association with a composite of adverse events. Conclusions: In Asian patients with HCM, measures of left atrial strain were independently associated with heart failure hospitalization and a composite of adverse outcomes. Left atrial strain may be used as a tool to predict adverse outcomes in patients with HCM. Full article

We report two cases of prolonged “unexpected” asystoles in patients with a wearable cardioverter-defibrillator (WCD) and a subcutaneous implantable cardioverter-defibrillator (ICD), respectively, which were promptly recognized and successfully managed. As these devices are designed to recognize and treat malignant tachyarrhythmias but do not provide pacing capabilities, it is crucial to identify patients with paroxysmal conduction disorders who might require backup pacing. For this reason, it is also important to leverage the monitoring features of both devices and their ability to detect the occurrence of bradyarrhythmias. Full article

Automated external defibrillator resources (AEDRs) are the crux of out-of-hospital cardiac arrest (OHCA) responses, enhancing safe and sustainable urban environments. However, existing studies failed to consider the nexus between built environment (BE) features and AEDRs. Can explainable machine-learning (ML) methods reveal the BE-AEDR nexus? This study applied an Optuna-based extreme gradient boosting (OP_XGBoost) decision tree model with SHapely Additive exPlanations (SHAP) and partial dependence plots (PDPs) aiming to scrutinize the spatial effects, relative importance, and non-linear impact of BE features on AEDR intensity across grid and block urban patterns in Tianjin Downtown, China. The results indicated, that (1) marginally, the AEDR intensity was most influenced by the service coverage (SC) at grid scale and nearby public service facility density (NPSF_D) at block scale, while synergistically, it was shaped by comprehensive accessibility and land-use interactions with the prioritized block pattern; (2) block-level granularity and (3) non-linear interdependencies between BE features and AEDR intensity existed as game-changers. The findings suggested an effective and generalizable approach to capture the complex interplay of the BE-AEDR and boost the AED deployment by setting health at the heart of the urban development framework. Full article

Background: The increasing use of technologies operating between 10 and 200 kHz, such as RFID, wireless power transfer systems, and induction cooktops, raises concerns about electromagnetic interference (EMI) with cardiac implantable electronic devices (CIEDs). The mechanisms of interaction within this frequency range have been only partially addressed by both the scientific and regulatory communities. Methods: A physical twin of a pacemaker/implantable defibrillator (PM/ICD) was developed to experimentally assess voltages induced at the input stage by low-to-mid-frequency magnetic fields. The setup simulates the two sensing modalities programmable in PMs/ICDs and allows for the analysis of different implant configurations, lead geometries, and positions within a human body phantom. Results: Characterization of the physical twin demonstrated its capability to reliably measure induced voltages in the range of 5 mV to 1.5 V. Its application enabled the identification of factors beyond the implant’s induction area that contribute to the induced voltage, such as the electrode-tissue interface and body-induced currents. Conclusions: This physical twin represents a valuable tool for experimentally validating the mechanisms of EMI in CIEDs, providing insights beyond current standards. The data obtained can serve as a reference for the validation of numerical models and patient-specific digital twins. Moreover, it offers valuable information to guide future updates and revisions of international electromagnetic compatibility standards for CIEDs. Full article

Background: The advent of subcutaneous implantable cardioverter defibrillators (S-ICDs) marked a significant milestone in the course of cardiac rhythm devices, particularly for patients who are deemed at high risk for ventricular arrhythmias and sudden cardiac death. This extracardiac approach makes the S-ICD an especially valuable option for young patients, those with difficult venous access, or those at high risk of infection. Although the S-ICD does not provide pacing for bradycardia or heart failure, it has shown efficacy in treating ventricular arrhythmias while minimizing complications associated with transvenous systems. Methods: The purpose of this multicenter retrospective analysis was to assess the real-world efficacy and safety of the S-ICD in a heterogeneous population. Results: The GASP registry consisted of 114 patients, 68% male, aged 41 ± 15 years, with a mean LVEF of 50%. In the follow-up of 35 months, inappropriate shocks occurred in 7% while appropriate shocks occurred in 6.2%. The most common reasons for inappropriate shocks were myopotentials and atrial tachyarrhythmias. Thirty-day complication-free rates were 97.3%, with the majority of patients requiring device extraction due to infection. Over the longer term, four patients required re-intervention due to local discomfort, while one device was extracted for infection. In a multivariate analysis, complications were not significantly higher in the sicker population, such as those with diabetes, kidney disease requiring dialysis, or heart failure. Conclusions: These findings support the growing role of the S-ICD as an alternative to the TV-ICD, especially in patients without pacing indications. Full article

Background/Objectives: Atrial fibrillation (AF) is a prevalent arrhythmia that significantly complicates the management of heart failure (HF) patients, particularly those who have implantable cardioverter–defibrillators (ICDs). The interplay between AF and inappropriate ICD therapy poses a critical challenge in optimizing patient outcomes, as inappropriate shocks can lead to increased morbidity, psychological distress, and a reduced quality of life. We aimed to explore the various clinical and demographic predictors of AF in HF patients with indications for ICD implantation. Methods: This study included 122 patients who were indicated for ICD implantation and had undergone transthoracic echocardiography (TE). We evaluated the relationships between clinical and demographic factors and the occurrence of AF, which was recorded either before ICD implantation or during the follow-up period afterward. From our findings, we established predictors and a risk model for AF. Results: Out of 122 HF patients with ICDs, 52 (42.6%) experienced an episode of AF either prior to ICD implantation or during a follow-up period of 20.5 [6.0; 53.0] months, as recorded by the ICDs’ endogram. Patients with AF were older compared to those without AF (p < 0.001). Additionally, they exhibited a higher left ventricular early diastolic filling rate (LVE) (p = 0.006) and a greater left atrial index (LAI) (p = 0.002). These three factors—age, LVE and LAI—were found to be independently associated with AF in both univariable and multivariable logistic regression analyses. The final model, including age, LVE, and LAI, showed a good discrimination capability with an AUC of 0.775. At a cutoff value of >0.47, the model achieved a sensitivity of 67.3% and a specificity of 77.2% in identifying HF patients with ICDs at risk for AF. Conclusions: This study found that 42.6% of HF patients with ICDs experienced AF, with older age, higher LVE, and greater LAI identified as significant predictors. Full article

Background: Frequent premature ventricular complexes (PVCs) are associated with adverse outcomes in patients with structural heart disease (SHD), including increased risk of mortality and impaired left ventricular ejection fraction (LVEF). While radiofrequency ablation (RFA) of idiopathic PVCs is well established, its role in patients with SHD remains less clear. Objective: To review the evidence on the efficacy of RFA for PVC suppression in patients with SHD, specifically evaluating its impact on LVEF and clinical outcomes. Methods: A review of the literature was conducted using PubMed and the Cochrane Library, focusing on studies published after 2010 that included adult patients with SHD and a PVC burden >4% on 24 h Holter monitoring. Studies including patients with presumed PVC-induced cardiomyopathy without underlying SHD were excluded. Key outcomes were LVEF recovery, functional status, and procedural success rates. Results: In ischemic cardiomyopathy, RFA reduced PVC burden significantly and resulted in modest but significant LVEF improvement. In non-ischemic cardiomyopathy, successful ablation improved LVEF by 8–12% on average and enhanced NYHA class. Across mixed cohorts, patients with sustained PVC suppression showed significant improvements in LVEF, functional status, which, in many cases, removed the indication for implantable cardioverter-defibrillators. Notably, procedural success rates ranged from 60 to 94%, and the high baseline PVC burden (>13–20%) consistently predicted LVEF recovery regardless of SHD etiology. Conclusions: RFA of frequent PVCs in patients with SHD leads to meaningful improvements in systolic function and symptoms, particularly in those with high PVC burden. These benefits are seen across ischemic and non-ischemic substrates, although procedural complexity and recurrence rates may be higher. PVC burden, rather than SHD presence alone, should guide patient selection for ablation. Full article

Background/Objectives: A significant subset of congenital heart disease (CHD) patients undergo a transvenous pacemaker (PM)/implantable cardioverter defibrillator (ICD) lead extraction (TLE) in their lifetime. We aimed to report on the outcome and complexity of TLEs in CHD patients for whom a powered mechanical sheath was used. Methods: This retrospective study included 175 consecutive TLEs performed at our centre. Overall, 13 TLEs in CHD patients and 162 TLEs in non-CHD patients were performed. A total of 264 leads were extracted. Results: CHD patients were younger than non-CHD patients at the time of their first lead implant (21.2 ± 17 vs. 57.1 ± 18 years; p < 0.01) and at the time of lead extraction (33.38 ± 13 vs. 63.31 ± 16 years; p < 0.01). The leads extracted from CHD patients were significantly older than the leads extracted from non-CHD patients (median: 8.0 vs. 4.0 years; p < 0.01). CHD patients and non-CHD patients did not differ in terms of the procedural (92% vs. 87%; p = 0.581) and clinical success rates (100% vs. 91%; p = 0.269). The two patient groups did not differ in terms of their procedural complication rate (0% vs. 11%; p = 0.191). There were no differences in the extraction techniques used, i.e., rotational mechanical sheaths were used in 61% of CHD extractions and in 38% of non-CHD extractions; p = 0.11. Conclusions: TLEs that use rotational mechanical sheaths as an advanced technique can be safely and effectively performed in CHD patients. The outcome and complexity of TLEs in CHD patients are comparable with those in non-CHD patients that undergo this procedure. Full article

Background: Professional knowledge and experience of healthcare organization went through continuous change and development with the progression of COVID-19 pandemic waves. However, carefully developed guidelines for cardiopulmonary resuscitation (CPR) remained largely unchanged regardless of the epidemic situation, with the largest change being a more prominent bioethical approach. It would be possible to further improve the quality of CPR by systematic data collection, the facilitation of prospective studies, and further development of the methodology based on this evidence, as well as by providing information and developing provisions on interventions with expected poor outcomes, and ultimately by refusing resuscitation. Methods: This study involved the critical collection and analysis of literary data originating from the Web of Science and PubMed databases concerning bioethical aspects and the efficacy of CPR during the COVID-19 pandemic. Results: According to the current professional recommendation of the European Resuscitation Council (ERC), CPR should be initiated immediately in case of cardiac arrest in the absence of an exclusionary circumstance. One such circumstance is explicit refusal of CPR by a well-informed patient, which in practice takes the form of a prior declaration. ERC prescribes the following conjunctive conditions for do-not-attempt CPR (DNACPR) declarations: present, real, and applicable. It is recommended to take the declaration as a part of complex end-of-life planning, with the corresponding documentation available in an electronic database. The pandemic has brought significant changes in resuscitation practice at both lay and professional levels as well. Incidence of out-of-hospital resuscitation (OHCA) did not differ compared to the previous period, while cardiac deaths in public places almost halved during the epidemic (p < 0.001) as did the use of AEDs (p = 0.037). The number of resuscitations performed by bystanders and by the emergency medical service (EMS) also showed a significant decrease (p = 0.001), and the most important interventions (defibrillation, first adrenaline time) suffered a significant delay. Secondary survival until hospital discharge thus decreased by 50% during the pandemic period. Conclusions: The COVID-19 pandemic provided a significant impetus to the revision of guidelines. While detailed methodology has changed only slightly compared to the previous procedures, the DNACPR declaration regarding self-determination is mentioned in the context of complex end-of-life planning. The issue of safe environment has come to the fore for both lay and trained resuscitators. Future Directions: Prospective evaluation of standardized methods can further improve the patient’s autonomy and quality of life. Since clinical data are controversial, further prospective controlled studies are needed to evaluate the real hazards of aerosol-generating procedures. Full article

Introduction: The prevention of heart failure (HF) exacerbation is crucial for patient prognosis, and preventive treatment for potential symptoms and warning signs is essential in this context. The TriageHF © algorithm has been retrospectively validated and has demonstrated good correlation with HF episodes. This study analyzes the effectiveness of the TriageHF © algorithm in routine clinical practice, emphasizing the role of episode duration in its predictive capacity. Materials and methods: From October 2017 to October 2020, all patients who received a Medtronic Amplia DR implant were prospectively selected for analysis. To evaluate the algorithm’s diagnostic capacity, it was compared with the clinical diagnosis of HF episodes during follow-up. Results: The sustained moderate-risk (more than 7 days) and high-risk alerts both showed high positive predictive values (11.25% and 27.27%, respectively), along with an increase in the relative risk of HF, particularly in high-risk alerts (hazard ratio is 46.21 times higher than for sustained moderate-risk alerts). Furthermore, there was higher event-free survival in real low-risk alerts than in both sustained medium-risk and high-risk alerts (p < 0.01). Conclusions: TriageHF © can predict the worsening of patients with ICD CRT. Medium-risk alerts lasting less than 7 days do not pose a greater risk of HF episodes, while high-risk alerts, regardless of their duration, are highly correlated with HF episodes. Full article

Out-of-hospital cardiac arrest remains a major cause of adult mortality worldwide, with survival to hospital discharge rates around 10%. Despite advances in prehospital care, rapid recognition and high-quality chest compressions are the primary interventions, while early defibrillation is one of the few measures shown to improve survival. This literature review examines novel interventions for patients with refractory ventricular fibrillation and pulseless ventricular tachycardia, focusing on double sequential defibrillation, beta-adrenergic receptor antagonists, and extracorporeal cardiopulmonary resuscitation. Evidence suggests that double sequential defibrillation may improve survival to discharge in refractory ventricular fibrillation, but consensus and large-scale validation are lacking. Beta-blockers show promise for increasing the rates of return of spontaneous circulation and favourable neurological outcomes, yet robust evidence is still needed. Extracorporeal cardiopulmonary resuscitation, particularly when initiated rapidly in selected patients, can enhance survival and neurological outcomes, though studies show mixed results and highlight the importance of patient selection and system readiness. Overall, while these interventions offer potential, their widespread adoption requires further high-quality research to determine efficacy, optimal protocols, and resource implications in both prehospital and emergency department settings. Full article

Introduction: Implantable defibrillator devices (ICDs) can be used for remote monitoring of different variables, including some related to Heart Failure (HF). Two different algorithms (TriageHF and HeartLogic) arise by combining some of these variables to generate an estimation of HF decompensation risk in the following days. Until now, no other trial has evaluated both algorithms in a head-to-head comparison. The primary objective is to compare diagnostic accuracy of both algorithms in a similar cohort of patients. Material and Methods: Descriptive monocentric cohort study of a series of 64 patients who have been implanted with a Medtronic or Boston Scientific ICD with the TriageHF or Heart Logic algorithm available during the period between January 2020 and June 2022, with a total of 27 patients in the HeartLogic group and 37 patients in the TriageHF group. Results: During the period of the study there were a total of 1142 alarms analyzed. There were no differences in the basal characteristics of both groups. We reported a risk alarm–patient ratio of 1.31 ± 1.89 in the HeartLogic group and of 3.32 ± 3.08 in the TriageHF group (p < 0.01). In the TriageHF group, we reported a lower specificity with (0.76), with higher sensitivity (0.97) and PPV (0.18), and similar NPV (1). Survival analysis shows no statistical differences between both algorithms in the 30 days following the alert. Conclusions: TriageHF algorithm had higher sensibility and PPV, leading to a higher number of alerts/patients, while HeartLogic algorithm had a better specificity. These differences should be considered to optimize patient follow-ups in home monitoring. Full article