Pulsed field ablation (PFA) with a pentaspline catheter has been recently approved by the FDA for catheter ablation of atrial fibrillation. Evidence of its application for ablation of ventricular arrhythmias (VAs) remains limited.

To evaluate the safety and efficacy of pentaspline PFA for VAs.

We included consecutive patients undergoing PFA with a pentaspline catheter (FARAWAVE™, Boston Scientific) for VT or PVC (May 2024-October 2024). PFA was utilized for large footprint VT substrate ablation in patients with large scars, or as a bailout approach after acute radiofrequency (RF) failure.

A total of 11 patients (age 70±7 years, ejection fraction 35±12%) were included. In nine patients, PFA was used for VT (seven ischemic cardiomyopathy, two non-ischemic), and in two patients for papillary muscle PVCs (one with concomitant AF ablation). In four patients, PFA was performed after acute RFA failure, and was successful at suppressing the targeted VT/PVC in all cases. In seven patients, PFA was performed for large VT substrate modification or PVC: in two patients, only PFA was used, whereas in the remaining five patients touch-up RFA was used to complete substrate modification. Non-inducibility of VT/PVC was achieved in all cases. During a mean follow up of six months, VT recurred in two patients and PVC in one. No procedural-related complications occurred.

In this first US series, VT/PVC ablation using a pentaspline PFA catheter for large VT substrate modification or following acute RFA failure appeared effective and safe, with promising acute and mid-term follow-up results.

MicroRNAs (miRNAs) are essential modulators of cardiac arrhythmias, influencing electrical remodeling, ion channel dynamics, and fibrosis. Dysregulated miRNAs, including miR-1, miR-21, and miR-328, contribute to arrhythmogenesis through altered ion channel expression, heightened fibrosis, and inflammation. Recent investigations have identified novel circulating miRNA signatures, such as hsa-miR-96-5p and hsa-miR-184, for postoperative atrial fibrillation after coronary artery bypass grafting, offering high predictive accuracy and targeting pathways such as mitogen-activated protein kinase and transforming growth factor beta, as revealed by biological pathway analysis. These miRNAs serve as noninvasive biomarkers for early risk assessment. Therapeutically, miRNA inhibitors and mimics, enhanced by nanoparticle and viral vector delivery, provide targeted interventions. Despite challenges in specificity and delivery, miRNA-based approaches hold transformative potential for arrhythmia diagnosis and personalized management.

The incidence of acute coronary syndrome (ACS) among young individuals is increasing, making it a leading cause of mortality in this population. This study aimed to develop and validate a risk prediction model for in-hospital major adverse cardiovascular events (MACE) in young ACS patients.

A retrospective analysis was performed to predict in-hospital MACE. Patients were divided into a training set (n = 342) and a testing set (n = 171). Screening variables were optimized using least absolute shrinkage and selection operator (LASSO) regression and univariable logistic regression analysis. A predictive nomogram model was developed through multivariate logistic regression. The model's discrimination and calibration were assessed using the receiver operating characteristic (ROC) curve, calibration plots, and Hosmer-Lemeshow goodness-of-fit tests. Clinical utility was evaluated using decision curve analysis (DCA).

White blood cell count, Killip classification, lymphocyte count, heart rate, triglycerides, and Gensini score were identified as significant predictors. The constructed nomogram demonstrated strong predictive performance. The area under the ROC curve (AUC) was 0.9242 (95% confidence interval [CI]: [0.8841-0.9643]) for the training set and 0.8346 (95% CI [0.742-0.9272]) for the testing set, with respective cut-off values of 0.107 and 0.119. Calibration was confirmed with Hosmer-Lemeshow statistics of 12.454 (p = 0.2558) in the training set and 7.16 (p = 0.7102) in the testing set. DCA showed threshold probabilities ranging from 0% to 100% in the training set and 0% to 90% in the testing set.

The proposed nomogram model demonstrated robust discrimination and calibration, offering a valuable tool for predicting the risk of in-hospital MACE in young ACS patients.

Risk stratification for sudden cardiac death (SCD) in heart failure (HF) patients is largely based on left ventricular ejection fraction (LVEF) of ≤35%. However, disease-related LV remodeling and medical treatment may change LVEF over time.

This study aimed to evaluate the temporal trends in LVEF in patients with HF who experience an SCD.

We performed 2 retrospective cohort studies (discovery and validation) of patients who experienced SCD after an established diagnosis of HF. Individuals were identified from 2 separate population-based studies of SCD in Oregon and California, if they underwent ≥2 echocardiographic evaluations performed at least 6 months apart.

The Oregon discovery cohort included 526 patients (male 63.9%; age 70.4 [13.2]), and the California validation cohort 191 patients (male 60.7%; age 74.6 [13.6]). In the discovery cohort, 45% of patients with LVEF of ≤35% on first assessment were reclassified to LVEF of >35% at final assessment (P < .001). Among patients with LVEF of 36%-49%, 66% were reclassified to either ≤35% or >50% (P < .001). In patients with LVEF of >50%, 32% were reclassified to LVEF of <50% (P < .001). Overall, 41.1% of patients in the discovery cohort were reclassified based on LVEF (P < .001). No distinguishing characteristics were identified between patients with an initial LVEF of ≤35% who improved or did not. Similar findings were observed in the validation cohort.

LVEF category changed significantly over time, resulting in substantial reclassification of risk before the SCD event. These findings highlight the major limitation of using LVEF measured at a single time point as the main predictor of SCD risk.

A case of an adolescent male with hypoplastic coronary arteries and myocardial bridging who had a sudden cardiac death event playing soccer. This rare anomaly is not easily identified and may be missed during routine work-up. Treatment options are limited and there is a need for discussion of additional treatment considerations that may prevent sudden cardiac death in this population.

The factors contributing to sustained ventricular arrhythmias (VAs) >30 days after left ventricular assist device (LVAD) implantation are not well-established.

This study aimed to predict the factors associated with late sustained VAs after LVAD implantation and develop a predictive score to identify patients with an increased risk of late sustained VAs after the procedure.

We performed a retrospective cohort study on a training cohort of 623 patients and a validation cohort of 157 patients who underwent LVAD implantation at the Mayo Clinic (Rochester, Phoenix, and Jacksonville) from January 1, 2000, to December 30, 2020. Late sustained VAs were defined as ventricular tachycardia (VT) and ventricular fibrillation (VF) occurring >30 days after the LVAD procedure. Detailed chart reviews of the electronic health records within the Mayo Clinic and outside medical records were performed.

A total of 780 patients were included in our study. Late sustained VAs occurred in 30% (n = 232) of the patients. The significant factors associated with late sustained VAs after LVAD were the history of VAs prior to LVAD (34.1% vs. 23.0%, p < 0.01), implantable cardiac defibrillator (ICD) (87.9% vs. 77.6%, p < 0.01) or cardiac resynchronization therapy (CRT) in situ (43.5% vs. 33.6%, p = 0.008), VT ablation prior to LVAD (5.2% vs. 1.8%, p = 0.010), use of amiodarone (49.1% vs. 38.7%, p = 0.007), use of mexiletine (15.5% vs. 5.7%, p < 0.01), and higher left ventricular end-diastolic diameter (LVEDD) on echocardiography prior to LVAD implantation (71.4 vs. 68.7 mm, p = 0.002). During follow-up, the patients who developed late sustained VAs after LVAD had lower survival than those who did not (HR = 1.96, 95% CI:156-2.4, p < 0.001). The average time from LVAD to orthotopic heart transplant was longer among late sustained VAs patients (23 vs. 14 months, p < 0.01). The "VIN" risk score was created to identify four risk groups: low (scores 0), intermediate (score 1), high (score 2), and very high (score 3). The rates of late VA's in the training cohort at 1 year were 9.5%, 14%, 18%, and 25% which was almost similar to the risk of late VA's at validation cohort 10%, 12%, 20%, and 63%, respectively.

Late sustained VAs occurred in 30% of the patients who received LVAD and were associated with lower survival. The VIN risk score was developed and validated to stratify patients into low, intermediate, high, and very high risk of late sustained VAs.

Epicardial access during electrophysiology procedures offers valuable insights and therapeutic options for managing ventricular arrhythmias (VAs). The current clinical consensus statement on epicardial VA ablation aims to provide clinicians with a comprehensive understanding of this complex clinical scenario. It offers structured advice and a systematic approach to patient management. Specific sections are devoted to anatomical considerations, criteria for epicardial access and mapping evaluation, methods of epicardial access, management of complications, training, and institutional requirements for epicardial VA ablation. This consensus is a joint effort of collaborating cardiac electrophysiology societies, including the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, the Latin American Heart Rhythm Society, and the Canadian Heart Rhythm Society.

Intercostal extravascular implantable cardioverter defibrillator (EV-ICD) leads may work better in contact with the pericardium thereby directing pacing and defibrillation energy towards excitable myocytes. We report 3-month safety and performance outcomes with a second-generation intercostal EV-ICD lead paired with standard, commercially available ICD pulse generators (PGs).

Subjects undergoing a transvenous ICD (TV-ICD) procedure received a concomitant intercostal EV-ICD lead system. The intercostal EV-ICD lead was connected sequentially to a PG in a left pectoral and then a left mid-axillary location. Extravascular ICD lead assessment included sensing and defibrillation of induced ventricular arrhythmias and pacing capture. The intercostal EV-ICD system was followed in a 'recording-only' mode and the control TV-ICD system in 'therapy delivery' mode to compare stored events. Devices were evaluated prior to hospital discharge, 2 weeks, 1 month, 2 months, and 3 months post-implant. Defibrillation testing was repeated prior to lead removal; 20/20 (100%) were successfully implanted (median implant time of 9 min). Two major lead complications were reported over a mean of 82 days: (i) lead movement and (ii) infection of both the TV-ICD and EV-ICD systems. Intraoperative pacing capture was achieved with the integrated bipolar configuration in 19 of 20 (95%) subjects. Pacing capture with the EV-ICD system was tolerated in all subjects, with over 90% feeling no pain after a 1-month recovery from the procedure. Induced VF episodes were sensed in all subjects and defibrillated successfully in 17 of 17 patients (100%) with a left mid-axillary PG and 19 of 20 patients (95%) with a left pectoral PG. Sensing and defibrillation were successful in 18 of 18 (100%) tested prior to lead removal.

In this pilot experience with a second-generation intercostal EV-ICD lead implantation, sensing and defibrillation of induced VF were successful when paired with a standard ICD PG from either a left mid-axillary or pectoral pocket.

NCT number: NCT05791032; URL: https://clinicaltrials.gov/study/NCT05791032.

Modified cardiac sympathetic denervation (CSD) with stellate ganglion (SG) sparing is a novel technique for cardiac neuromodulation in patients with refractory ventricular tachycardia (VT).

Our aim is to describe the mid- to long-term clinical outcome of the modified CSD with SG sparing in a series of patients with structural heart disease (SHD) and refractory VT.

All consecutive patients with SHD and refractory VT undergoing modified CSD were enrolled. Baseline clinical characteristics and periprocedural data were collected for all patients. The primary outcome was any recurrence of sustained VT.

We enrolled 15 patients (age: 69.2 ± 7.9 years; male 100%) undergoing modified CSD. Left ventricular ejection fraction was 37 ± 11% and all patients had an implantable cardiac defibrillator (ICD); the underlying cardiomyopathy was non-ischemic in 73.3% of them. At least one previous ablation had been attempted in 66.6% of cases. The 73.3% of patients underwent bilateral CSD and the mean effective surgical time was 10.8 ± 2.4 min per side; no major periprocedural complication occurred. After a median follow-up time of 15 months (IQR: 8.5-24.5 months), the primary outcome occurred in 47.6% of cases. All patients experienced a reduction of ICD shocks after CSD (3.1 ICD shocks/patient before vs. 0.3 ICD shocks/patient after CSD; p-value: 0.001). Bilateral CSD and a VT cycle length < 340 ms were associated with better outcomes.

A modified CSD approach with stellate ganglion sparing appears to be safe, fast, and effective in the treatment of patients with SHD and refractory VTs.

Fatal arrhythmic events (FAEs), such as sudden cardiac death (SCD) and fatal ventricular arrhythmias, are a devastating complication in patients with coronary artery disease (CAD). Therefore, in this study we aimed to assess the incidence of FAEs in more recent Japanese patients with CAD and to examine whether risk stratification of FAEs can still be feasible using the left ventricular ejection fraction (LVEF).

In the CREDO Kyoto PCI/CABG registry cohorts-2 and -3, there were 25,843 patients with LVEF data who received a first coronary revascularization (LVEF ≤35% group: N=1,671, 35%45%: N=21,503). FAEs were defined as a composite of SCD or hospitalization for serious ventricular arrhythmias. The cumulative 5-year incidence of FAEs was 2.4% and it increased with decreasing LVEF (LVEF ≤35%: 8.84%, 35%45%: 1.67%, log-rank P<0.0001). The adjusted risk of FAEs also increased with decreasing LVEF.

LVEF is still a strong independent factor for predicting FAEs in patients with CAD in the PCI era. There was no obvious decrease in the incidence of FAEs between the 2 cohorts. The risk factors for FAEs through the 2 cohorts, other than low LVEF, included age ≥75 years, diabetes, heart failure, hemodialysis, atrial fibrillation, and anemia.

Serum potassium levels are recognized for their prognostic significance in patients presenting with acute myocardial infarction (AMI). However, the correlation between potassium level fluctuations and mortality rates among AMI patients remains unclear.

A retrospective cohort study was conducted using the MIMIC-IV database, including deidentified data from patients admitted to the Beth Israel Deaconess Medical Center from 2008 to 2022. Potassium fluctuation was assessed using parameters including mean postadmission serum potassium levels (K+[mean]), first measurable value upon admission (K+[admission]), minimum (K+[min]) and maximum (K+[max]) measurable values, and coefficient of variation (K+[CV]). The primary outcome was all-cause in-hospital mortality; secondary outcomes included ventricular tachycardia or fibrillation (VT/VF) and cardiac arrest. Restricted cubic spline models and logistic regression models were used to assess the associations between potassium fluctuation and clinical outcomes.

A J-shaped correlation between serum potassium levels and the risk of in-hospital mortality was identified. Both high and low potassium levels were significantly associated with increased mortality. Specifically, K+[mean] levels below 3.5 mmol/L and above 4.5 mmol/L were associated with higher mortality. Elevated K+[CV] values were also associated with higher in-hospital mortality in both univariate and multivariate analyses. Increased potassium variability was correlated with elevated risks of both VT/VF and cardiac arrest.

Serum potassium fluctuation is an independent predictive factor for in-hospital mortality among AMI patients. These findings underscore the importance of maintaining potassium homeostasis in the management of AMI, suggesting that monitoring and stabilizing potassium levels are crucial for reducing in-hospital mortality.

Spontaneous type-1 Brugada patterns are associated with an elevated risk of major arrhythmic events, yet the relationship between varying degrees of pattern burden and the occurrence of a first major arrhythmic event remains unclear. This retrospective cohort study included 64 adult patients with a spontaneous type-1 Brugada pattern, who were identified at Mayo Clinic sites and followed for ≥12 months after the initial diagnosis. All patients underwent at least three 12-lead electrocardiograms (ECGs) within the first year. Individuals with prior major arrhythmic events were excluded. The percentage of ECGs showing a type-1 pattern was calculated and categorized as paroxysmal (<50%), persistent (50-99%), or permanent (100%). During a median follow-up of 92 months, seven patients (11%) experienced their first major arrhythmic event. Of these, one had paroxysmal, four had persistent, and two had permanent spontaneous type-1 Brugada patterns. Although statistical significance was not reached, the hazard ratios suggested a trend toward increased risk with persistent and permanent patterns compared to paroxysmal patterns. No sudden cardiac deaths occurred during follow-up. These findings suggest that a higher burden of spontaneous type-1 Brugada patterns may be associated with increased arrhythmic risk.

Brugada syndrome (BrS), a genetic disorder affecting cardiac ion channels, predominantly manifests due to mutations that impair the function of the Nav1.5 sodium channel's α-subunit. This condition, identified by Josep and Pedro Brugada, is often marked by symptoms such as syncope and episodes of polymorphic ventricular tachycardia (PVT) or ventricular fibrillation (VF). These arrhythmias, if not managed promptly, can escalate to sudden cardiac death (SCD), notably in patients whose cardiac structure appears normal. Given this, the prompt recognition and stratification of individuals at elevated risk are critical. This review elaborates on the current insights into BrS, focusing on recent diagnostic techniques, risk assessment strategies, and therapeutic advancements. It also critically examines ongoing controversies in the field.

This retrospective cohort study aimed to investigate the efficacy of dual-chamber left Bundle branch pacing (LBBP) as an alternative therapy for heart failure patients with complete left bundle branch block (CLBBB) and indications for defibrillator with cardiac resynchronization therapy (CRT-D).

34 patients met inclusion criteria were enrolled in the study. These criteria included a left ventricular ejection fraction (LVEF) of lower than 35%, a New York Heart Association functional class of II-IV, CLBBB meeting Strauss's criteria, intraventricular dyssynchrony, and confirmed correction of CLBBB during LBBP. Patients with ischemic cardiomyopathy, left ventricular noncompaction, significant late gadolinium enhancement (LGE) on cardiac magnetic resonance imaging (CMR), and indications for an implantable cardioverter-defibrillator (ICD) as secondary prevention were excluded.

Post-LBBP, the LVEF improved from 31.1 ± 4.0% to 61.0 ± 6.0% (P < 0.001). All patients exhibited a super-response to LBBP cardiac resynchronization therapy, achieving complete improvement in cardiac function with a LVEF exceeding 50%. Septal-to-posterior wall motion delay (SPWMD) and systolic dyssynchrony index (SDI) were indicators of intraventricular synchrony, SPWMD decreased from 271.4 ± 76.4 ms to 42.2 ± 22.9 ms (P < 0.001), and SDI decreased from 12.5 ± 5.3% to 1.9 ± 1.0% after implantation (P < 0.001).

Heart failure patients meeting the following criteria may be considered for dual-chamber pacing as an alternative to CRT-D, potentially avoiding the need for ICD implantation: (1) CLBBB meeting Strauss's criteria, (2) presence of intraventricular dyssynchrony on echocardiogram, (3) exclusion of secondary prevention ICD indications, (4) absence of evident LGE on CMR, and (5) successful correction of CLBBB during LBBP.

The prognostic value of left ventricular (LV) papillary muscle anomalies in dilated cardiomyopathy (DCM) patients is unclear. The objective of this study was to evaluate the prognostic significance of LV papillary muscle anomalies in DCM patients using cardiac magnetic resonance (CMR).

369 DCM patients who underwent CMR at two Chinese medical facilities from January 2019 to June 2023 were retrospectively and consecutively included in total. The various features of the LV papillary muscles were taken into consideration: thickness, attachment, supernumerary papillary muscles, angles, and signal intensity. The end-systolic signal hypointensity of both papillary muscles in early post-contrast cine CMR images was identified as Dark-Paps. Major adverse cardiac events (MACEs) were assessed, and all patients were followed up.

119 patients (32.2 %) had Dark-Paps and 141 patients (38.2 %) experienced MACE during a median follow-up of 22 months. According to Kaplan-Meier curve analysis, patients who had Dark-Paps had a lower survival rate free from MACE (log-rank, p < 0.001). Dark-Paps maintained an independent predictor of MACE in a multivariate model that included left ventricular ejection fraction (LVEF) and late gadolinium enhancement (LGE) extent (HR: 3.49; p < 0.001). Furthermore, adding Dark-Paps to the multivariate model greatly enhanced the prognostic role of endpoint events (C-statistic improvement: 0.652-0.777, Delong test: p < 0.001).

Dark-Paps is a potent independent indicator of major adverse cardiac events in dilated cardiomyopathy patients. In addition, Dark-Paps can provide additional prognostic value over the multivariable baseline clinical model.

Flecainide and other class-Ic antiarrhythmic drugs (AADs) are widely used in Andersen-Tawil syndrome type 1 (ATS1) patients. However, class-Ic drugs might be proarrhythmic in some cases. We investigated the molecular mechanisms of class-I AADs proarrhythmia and whether they might increase the risk of death in ATS1 patients with structurally normal hearts.

Of 53 ATS1 patients reviewed from the literature, 54% responded partially to flecainide, with ventricular arrhythmia (VA) reduction in only 23%. Of the latter patients, VA persisted in 20-50%. Flecainide was ineffective in 23%, and surprisingly, 13.5% suffered a non-fatal cardiac arrest. In five cardiac-specific ATS1 mouse models (Kir2.1Δ314-315, Kir2.1C122Y, Kir2.1G215D and Kir2.1R67W and Kir2.1S136F), flecainide or propafenone (40 mg/Kg i.p.) differentially prolonged the P wave, and the PR, QRS and QTc intervals compared to Kir2.1WT; Kir2.1S136F had milder effects. Flecainide increased VA inducibility in all mutant mice except Kir2.1S136F, which exhibited significant VA reduction. At baseline, Kir2.1G215D cardiomyocytes had the lowest inward rectifier K+ channel (IK1) reduction, followed by Kir2.1C122Y, Kir2.1R67W and Kir2.1S136F. Kir2.1C122Y cardiomyocytes had a significant decrease in sodium inward current (INa). Flecainide (10 μM) slightly increased IK1 density in Kir2.1WT and Kir2.1S136F, while it decreased both IK1 and INa in Kir2.1C122Y and Kir2.1R67W, despite normal trafficking of mutant channels. Optical mapping in ATS1 patient-specific iPSC-CM monolayers expressing Kir2.1C122Y, Kir2.1G215D and Kir2.1R67W showed an increase in rotor incidence at baseline and under flecainide, confirming the drugś proarrhythmic effect. Lastly, in-silico molecular docking predicts that the Kir2.1-Cys311 pharmacophore-binding site is altered in Kir2.1C122Y heterotetramers, reducing flecainide accessibility and leading to channel closure and arrhythmias.

Class-Ic AADs are only partially effective and might be proarrhythmic in some ATS1 patients. Kir2.1 mutations impacting the resting membrane potential and cellular excitability create a substrate for life-threatening arrhythmias, raising significant concern about using these drugs in some ATS1 patients.

The Bruton's Tyrosine Kinase Inhibitor, ibrutinib, has been widely employed due to its significant efficacy in B-cell lymphoma. However, the subsequent cardiac complications, notably atrial fibrillation (AF) and ventricular arrhythmias (VAs),associated with ibrutinib treatment have emerged as a major concern in cardio-oncology and hematology. Ibrutinib-induced AF has been well described, whereas mechanisms of ibrutinib-induced VAs are still under-investigation. The incidence of ibrutinib-induced VAs can vary vastly due to under-recognition and limitations of the retrospective studies. Recent investigations, including our previous work, have proposed several potential mechanisms contributing to this adverse event, necessitating further validation. The development of effective strategies for the prevention and treatment of ibrutinib-induced VAs still requires in-depth exploration. This review aims to establish a comprehensive framework encompassing the epidemiology, mechanistic insights, and clinical considerations related to ibrutinib-induced VAs. This article outlines potential strategies for the clinical management of patients undergoing ibrutinib therapy based on suggested mechanisms.

Several algorithms can differentiate inferior axis premature ventricular contractions (PVCs) originating from the right side and left side on 12-lead electrocardiograms (ECGs). However, it is unclear whether distinguishing the origin should rely solely on PVC or incorporate sinus rhythm (SR). We compared the dual-rhythm model (incorporating both SR and PVC) to the PVC model (using PVC alone) and quantified the contribution of each ECG lead in predicting the PVC origin for each cardiac rotation.

This multicentre study enrolled 593 patients from 11 centres-493 from Japan and Germany, and 100 from Belgium, which were used as the external validation data set. Using a hybrid approach combining a Resnet50-based convolutional neural network and a transformer model, we developed two variants-the PVC and dual-rhythm models-to predict PVC origin. In the external validation data set, the dual-rhythm model outperformed the PVC model in accuracy (0.84 vs. 0.74, respectively; P < 0.01), precision (0.73 vs. 0.55, respectively; P < 0.01), specificity (0.87 vs. 0.68, respectively; P < 0.01), area under the receiver operating characteristic curve (0.91 vs. 0.86, respectively; P = 0.03), and F1-score (0.77 vs. 0.68, respectively; P = 0.03). The contributions to PVC origin prediction were 77.3% for PVC and 22.7% for the SR. However, in patients with counterclockwise rotation, SR had a greater contribution in predicting the origin of right-sided PVC.

Our deep learning-based model, incorporating both PVC and SR morphologies, resulted in a higher prediction accuracy for PVC origin, considering SR is particularly important for predicting right-sided origin in patients with counterclockwise rotation.

Sudden cardiac death (SCD) is a common mode of death in patients with congestive heart failure (CHF). Implantable cardioverter defibrillator (ICD) implantation is established treatment for SCD prevention, but current eligibility criteria based on left ventricular ejection fraction (LVEF) and New York Heart Association (NYHA) functional class may be due for reconsideration given the increasing effectiveness of pharmacological therapy. We sought to reconsider the risk stratification of SCD in patients with symptomatic CHF.

In total, 1,676 consecutive patients (74 ± 13 years old; 56% male) with NYHA class II or III CHF between 2008 and 2015 were enrolled for this prospective study. The endpoint was SCD.

During a median (interquartile range) follow-up period of 25 (4-70) months, 198 (11.8%) patients suffered SCD. Of those events, 23% occurred within 3 months of discharge. In the adjusted analyses, estimated glomerular filtration rate (eGFR) < 30 ml/min/1.73 m2 [hazard ratio (HR) 1.73, 95% confidence interval (CI) 1.11-2.70, P = 0.01] and LVEF ≤ 35% (HR 2.31, 95% CI 1.47-3.66, P < 0.01) were independent risk predictors of SCD. Addition of eGFR to LVEF significantly improved prediction of SCD in the C-index (P = 0.04), and in two metrics, net reclassification improvement (P = 0.01) and integrated discrimination improvement (P = 0.03). The predictive power of eGFR declined time-dependently over 2 years.

The addition of eGFR to current eligibility criteria may be useful for risk assessment of SCD, although its predictive power wanes over time. Roughly a quarter of the SCD occurred within 3 months after discharge in patients with CHF.

Youth and adult participation in sports continues to increase, and athletes may be diagnosed with potentially arrhythmogenic cardiac conditions. This international multidisciplinary document is intended to guide electrophysiologists, sports cardiologists, and associated health care team members in the diagnosis, treatment, and management of arrhythmic conditions in the athlete with the goal of facilitating return to sport and avoiding the harm caused by restriction. Expert, disease-specific risk assessment in the context of athlete symptoms and diagnoses is emphasized throughout the document. After appropriate risk assessment, management of arrhythmias geared toward return to play when possible is addressed. Other topics include shared decision-making and emergency action planning. The goal of this document is to provide evidence-based recommendations impacting all areas in the care of athletes with arrhythmic conditions. Areas in need of further study are also discussed.

Cardiac arrhythmias are among the most important pathologies that cause sudden death. The exploration of new therapeutic options against arrhythmias with low undesirable effects is of paramount importance.

However, the convenient and typical animal model for screening the potential lead compound becomes a very critical modality, particularly in anti-arrhythmia. In this study, mice were intraperitoneally (i.p.) injected with BaCl2, CaCl2, and adrenaline to induce arrhythmia, and simultaneously compared with BaCl2-induced rats.

Electrocardiogram (ECG) showed that the majority of mice repeatedly developed ventricular bigeminy, ventricular tachycardia (VT), and ventricular fibrillation (VF) after BaCl2-injection as seen in rats. The ECG of mice developed ventricular bigeminy and VT after CaCl2 and AT after adrenaline i.p. injection. Additionally, acute cardiac arrhythmia after BaCl2 i.p. injection could be reverted by drugs (lidocaine and amiodarone) administration. Additionally, the different routes of administration for various chemical-induced arrhythmia in both mice and rats were also retrieved from PubMed and summarized. Comparing this approach with previous studies after the literature review reveals that arrhythmia of BaCl2-induced i.p. mice is compatible with the induction of other routes.

This study brings an alternative experimental model to investigate antiarrhythmic theories and provides a promising approach to discovering new interventions for acute arrhythmias.

Premature Ventricular Complexes (PVCs) are very common in clinical practice, with frequent PVCs (more than 30 beats per hour) or polymorphic PVCs significantly increasing the risk of mortality. Previous studies have shown that vagus nerve stimulation improves ventricular arrhythmias. Stimulation of the auricular distribution of the vagus nerve has proven to be a simple, safe, and effective method to activate the vagus nerve. Transcutaneous au ricular vagus nerve stimulation (taVNS) has shown promise in both clinical and experimental setting for PVCs; however, high-quality clinical studies are lacking, resulting in insufficient evidence of efficacy.

The study is a prospective, randomized, parallel-controlled trial with a 1:1 ratio between the two groups. Patients will be randomized to either the treatment group (taVNS) or the control group (Sham-taVNS) with a 6-week treatment and a subsequent 12-week follow-up period. The primary outcome is the proportion of patients with a ≥ 50% reduction in the number of PVCs monitored by 24-hour Holter. Secondary outcomes include the proportion of patients with a ≥ 75% reduction in PVCs, as well as the changes in premature ventricular beats, total heartbeats, and supraventricular premature beats recorded by 24-hour Holter. Additional assessments compared score changes in PVCs-related symptoms, as well as the score change of self-rating anxiety scale (SAS), self-rating depression scale (SDS), and 36-item short form health survey (SF-36).

The TASC-V trial will help to reveal the efficacy and safety of taVNS for frequent PVCs, offering new clinical evidence for the clinical practice.

Clinicaltrials.gov: NCT04415203 (Registration Date: May 30, 2020).

The increasing use of intracardiac echocardiography (ICE) in the ablation of premature ventricular complexes (PVCs) has raised questions about its true efficacy and safety.

This retrospective study collected the periprocedural complications and PVC burden post ablation. The risk factors of PVC recurrence was further explored.

The study included patients treated without ICE (control group, n = 451) and with ICE (ICE group, n = 155) from May 2019 to July 2022. The ICE group demonstrated significantly lower fluoroscopy times and X-ray doses. There were no major complications in the ICE group, and the difference in the occurrence of periprocedural complications between the groups was not statistically significant (p = 0.072). The long-term success rates were similar for the control and ICE groups (89.6% and 87.1%, respectively). The origin of PVCs was identified as the independent factor for ablation success.

The use of ICE did not confer an advantage with regard to long-term success in PVCs ablation. To thoroughly evaluate the safety and effectiveness of ICE in PVCs ablation, a prospective, multicenter, randomized study is warranted.

Catheter ablation (CA) is effective in the treatment of ventricular tachycardia (VT). Although some observational data suggest patients with non-ischemic cardiomyopathy (NICM) have less favorable outcomes when compared to those with an ischemic etiology (ICM), direct comparisons are rarely reported. We aimed to compare the outcomes of VT ablation in a propensity-score matched population of ICM or NICM patients.

Single-center retrospective study of consecutive patients undergoing VT ablation from 2012 to 2023. A propensity score (PS) was used to match ICM and NICM patients in a 1:1 fashion according to age, sex, left ventricular ejection fraction (LVEF), NYHA class, electrical storm (ES) at presentation, and previous endocardial ablation. The outcomes of interest were VT-free survival and all-cause mortality.

The PS yielded two groups of 71 patients each (mean age 63±10 years, 92% male, mean LVEF 35±10%, 36% with ES at presentation, and 23% with previous ablation), well matched for baseline characteristics. During a median follow-up of 2.3 (interquartile range IQR 1.3-3.8) years, patients with NICM had a significantly lower VT-free survival (53.5% vs. 69.0%, log-rank p=0.037), although there were no differences regarding all-cause mortality (22.5% vs. 16.9%, log-rank p=0.245). Multivariate analysis identified NICM (HR 2.34 [95% CI 1.32-4.14], p=0.004), NYHA class III/IV (HR 2.11 [95% CI 1.11-4.04], p=0.024), and chronic kidney disease (HR 2.23 [95% CI 1.25-3.96], p=0.006), as independent predictors of VT recurrence.

Non-ischemic cardiomyopathy patients were at increased risk of VT recurrence after ablation, although long-term mortality did not differ.

Despite the positive impact of implantable cardioverter defibrillators (ICDs) and wearable cardioverter defibrillators (WCDs) on prognosis, their implantation is often withheld especially in Japanese heart failure patients with reduced left ventricular ejection fraction (HFrEF) who have not experienced ventricular tachycardia (VT) or ventricular fibrillation (VF) for uncertain reasons. Recent advancements in heart failure (HF) medications have significantly improved the prognosis for HFrEF. Given this context, a critical reassessment of the treatment and prognosis of ICDs and WCDs is essential, as it has the potential to reshape awareness and treatment strategies for these patients.

We are initiating a prospective multicenter observational study for HFrEF patients eligible for ICD in primary and secondary prevention, and WCD, regardless of device use, including all consenting patients. Study subjects are to be enrolled from 31 participant hospitals located throughout Japan from April 1, 2023, to December 31, 2024, and each will be followed up for 1 year or more. The planned sample size is 651 cases. The primary endpoint is the rate of cardiac implantable electronic device implementation. Other endpoints include the incidence of VT/VF and sudden death, all-cause mortality, and HF hospitalization, other events. We will collect clinical background information plus each patient's symptoms, Clinical Frailty Scale score, laboratory test results, echocardiographic and electrocardiographic parameters, and serial changes will also be secondary endpoints.

Not applicable.

This study offers invaluable insights into understanding the role of ICD/WCD in Japanese HF patients in the new era of HF medication.

This study aimed to describe the genetic and clinical characteristics of paediatric cardiomyopathy in a cohort of Chinese patients.

We retrospectively reviewed the clinical history and mutation spectrum of 75 unrelated Chinese paediatric patients who were diagnosed with cardiomyopathy and referred to our hospital between January 2016 and December 2022.

Seventy-five children with cardiomyopathy were enrolled, including 32 (42.7%) boys and 43 (57.3%) girls. Dilated cardiomyopathy was the most prevalent cardiomyopathy (61.3%) in the patients, followed by hypertrophic cardiomyopathy (17.3%), ventricular non-compaction (14.7%), restrictive cardiomyopathy (5.3%) and arrhythmogenic right ventricular cardiomyopathy (1.3%). Whole-exome sequencing and targeted next-generation sequencing identified 34 pathogenic/likely pathogenic variants and 1 copy number variant in 14 genes related to cardiomyopathy in 30 children, accounting for 40% of all patients. TNNC1 p.Asp65Asn and MYH7 p.Glu500Lys have not been reported previously. The follow-up time ranged from 2 months to 6 years. Twenty-two children died (mortality rate 29%).

Comprehensive genetic testing was associated with a 40% yield of causal genetic mutations in Chinese cardiomyopathy cases. We found diversity in the mutation profile in different patients, which suggests that the mutational background of cardiomyopathy in China is heterogeneous, and the findings may be helpful to those counselling patients and families.

There is limited evidence regarding the use of subcutaneous implantable cardioverter-defibrillators (S-ICD) in pediatric patients. The aim of this study was to determine the incidence of complications in these patients at our center, according to the type of ICD and patient size.

We included all patients aged<18 years who received an S-ICD since 2016 at our center. As a control group, we also included contemporary patients (since 2014) who received a transvenous ICD (TV-ICD). The primary endpoint was a composite of complications and inappropriate shocks.

A total of 26 patients received an S-ICD (median age, 14 [5-17] years; body mass index [BMI], 20.2 kg/m2). Implantation was intermuscular in 23 patients (88%) and subserratus in the remainder. Two incisions were used in 24 patients (92%). In all patients, 2 zones were programmed: a conditional zone set at 230 (220-230) bpm, and a shock zone set at 250 bpm. Nineteen patients received a TV-ICD (median age, 11 [range, 5-16] years; BMI, 19.2 kg/m2, 79% single-chamber). Survival free from the primary endpoint at 5 years was 80% in the S-ICD group and 63% in the TV-ICD group (P=.54). Survival free from inappropriate shocks was similar (85% vs 89%, P=.86), while survival free from complications was higher in the S-ICD group (96% vs 57%, cloglog P=.016). There were no therapy failures in the S-ICD group, and no increased complication rates were observed in patients with BMI ≤20 kg/m2.

With contemporary implantation techniques and programming, S-ICD is a safe and effective therapy in pediatric patients. The number of inappropriate shocks is similar to TV-ICD, with fewer short- and mid-term complications.

Fulminant myocarditis is an acute diffuse inflammatory disease of myocardium. It is characterized by acute onset, rapid progress and high risk of death. Its pathogenesis involves excessive immune activation of the innate immune system and formation of inflammatory storm. According to China's practical experience, the adoption of the "life support-based comprehensive treatment regimen" (with mechanical circulation support and immunomodulation therapy as the core) can significantly improve the survival rate and long-term prognosis. Special emphasis is placed on very early identification,very early diagnosis,very early prediction and very early treatment.