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Aims Methods Conclusion Timely referrals for transplantation and left ventricular assist device (LVAD) play a key role in favourable outcomes in patients with advanced heart failure (HF). Cardiovascular mortality, driven by sudden cardiac death, is the main reason for dying while waiting for heart transplantation (HTx). The purpose of the Preventive Catheter Ablation for ventricular arrhythmiaS in patients with end‐sTage heart faiLure rEferred for heart transplantation eValuaTion (CASTLE‐VT) trial is to test the hypothesis that prophylactic catheter ablation of arrhythmogenic ventricular scar tissue will reduce mortality, need for LVAD implantation, and urgent HTx in patients with end‐stage HF related to ischaemic cardiomyopathy (ICM).CASTLE‐VT is a randomized evaluation of prophylactic ablative treatment of arrhythmogenic ventricular scar in patients referred for HTx evaluation and diagnosed with ICM. Ablation will be performed with the use of a substrate‐based approach in which the myocardial scar is mapped and ablated while the heart remains predominantly in sinus rhythm. The primary endpoint is the composite of all‐cause mortality, worsening of HF requiring prioritized transplantation or LVAD implantation. The main secondary study endpoints are all‐cause mortality, cardiovascular mortality, incidence of implantable cardioverter‐defibrillator (ICD) therapy, hospitalizations, quality of life, time to first ICD therapy, number of device‐detected ventricular tachycardia/ventricular fibrillation episodes, left ventricular function, and exercise tolerance. CASTLE‐VT will randomize 160 patients with a follow‐up period of 2 years.CASTLE‐VT will determine whether prophylactic catheter ablation of arrhythmogenic ventricular scar tissue reduces mortality in patients with end‐stage HF who are referred for HTx evaluation. [ABSTRACT FROM AUTHOR]

This case report presents a notable instance of subcutaneous implantable cardioverter defibrillator (S-ICD) implantation in a 9-year-old patient diagnosed with Timothy syndrome (TS), which is a rare condition characterized by mutations in the CACNA1c gene. Conventional therapies often have limited efficacy in managing TS. This case is significant, as it represents the youngest age for S-ICD implantation recorded in mainland China. While the absence of ventricular arrhythmias during hospitalization and follow-up is encouraging, it is not sufficient to conclusively establish the safety and feasibility of this intervention in young TS patients. Further research is needed to evaluate the long-term outcomes and to consider S-ICD as a potential standard treatment option for TS. Additionally, there is a need for a more detailed exploration of the molecular mechanisms underlying gene therapy and personalized interventions. [ABSTRACT FROM AUTHOR]

Objectives: To perform a systematic review and meta-analysis of studies investigating the diagnostic value of cardiac magnetic resonance (CMR) features for arrhythmic risk stratification in mitral valve prolapse (MVP) patients. Materials and methods: EMBASE, PubMed/MEDLINE, and CENTRAL were searched for studies reporting MVP patients who underwent CMR with assessment of: left ventricular (LV) size and function, mitral regurgitation (MR), prolapse distance, mitral annular disjunction (MAD), curling, late gadolinium enhancement (LGE), and T1 mapping, and reported the association with arrhythmia. The primary endpoint was complex ventricular arrhythmias (co-VAs) as defined by any non-sustained ventricular tachycardia, sustained ventricular tachycardia, ventricular fibrillation, or aborted sudden cardiac death. Meta-analysis was performed when at least three studies investigated a CMR feature. PROSPERO registration number: CRD42023374185. Results: The meta-analysis included 11 studies with 1278 patients. MR severity, leaflet length/thickness, curling, MAD distance, and mapping techniques were not meta-analyzed as reported in < 3 studies. LV end-diastolic volume index, LV ejection fraction, and prolapse distance showed small non-significant effect sizes. LGE showed a strong and significant association with co-VA with a LogORs of 2.12 (95% confidence interval (CI): [1.00, 3.23]), for MAD the log odds-ratio was 0.95 (95% CI: [0.30, 1.60]). The predictive accuracy of LGE was substantial, with a hierarchical summary ROC AUC of 0.83 (95% CI: [0.69, 0.91]) and sensitivity and specificity rates of 0.70 (95% CI: [0.41, 0.89]) and 0.80 (95% CI: [0.67, 0.89]), respectively. Conclusions: Our study highlights the role of LGE as the key CMR feature for arrhythmia risk stratification in MVP patients. MAD might complement arrhythmic risk stratification. Clinical relevance statement: LGE is a key factor for arrhythmogenic risk in MVP patients, with additional contribution from MAD. Combining MRI findings with clinical characteristics is critical for evaluating and accurately stratifying arrhythmogenic risk in MVP patients. Key Points: MVP affects 2–3% of the population, with some facing increased risk for arrhythmia. LGE can assess arrhythmia risk, and MAD may further stratify patients. CMR is critical for MVP arrhythmia risk stratification, making it essential in a comprehensive evaluation. [ABSTRACT FROM AUTHOR]

Background: The association between the triglyceride-glucose (TyG) index and ventricular arrhythmias (VAs) is unclear. This study aimed to investigate the relationship between the TyG index, VAs, and major cardiovascular events in patients at high risk of sudden cardiac death (SCD). Methods: We enrolled 1046 patients at high risk of SCD with an indication for implantable cardioverter-defibrillator (ICD) implantation at the Chinese National Center for Cardiovascular Diseases. The primary outcome was VAs, defined as sustained ventricular tachycardia and ventricular fibrillation documented by the ICD. The secondary outcomes were cardiac mortality, heart transplantation, and rehospitalization for heart failure. Results: The mean (± SD) age was 59.6 ± 14.0 years old, and 25.7% were female. During the mean follow-up of 36.1 months, 342 (32.7%) patients had VAs, and 185 (17.7%) patients had major cardiovascular events. The mean fasting glucose and triglyceride levels were 111.9 ± 42.7 mg/dL and 140.0 ± 95.4 mg/L, respectively, with a TyG index range of 6.96–11.8. In the Fine-Gray subdistribution hazard model analysis, an increase in the TyG index was associated with a significant increase in the VAs (per 1 TyG index, hazard ratio [HR] 2.95; 95% confidence interval [CI], 2.29–3.80) and secondary outcome (HR 2.84; 95% CI 1.86–4.34). When stratified into tertiles, the risk of VAs was significantly higher in the highest tertile (HR 4.08; 95% CI, 2.81–5.92) than in the lowest tertile. Analysis of the secondary outcome revealed similar findings (HR 3.18; 95% CI, 1.73–5.85). Conclusions: In our cohort, the pre-operational TyG index is significantly associated with VAs and major cardiovascular events for patients with high risk of SCD. [ABSTRACT FROM AUTHOR]

Background: Antiarrhythmic therapy for recurrent ventricular arrhythmias (VAs) in patients having undergone catheter ablation and in whom amiodarone and/or beta-blockers were ineffective or contraindicated is a controversial issue. Purpose: The present study sought to compare the efficacy and tolerability of oral procainamide and mexiletine in patients with recurrent ventricular arrhythmias when the standard therapy strategy failed. Methods: All patients with an implantable cardioverter defibrillator (ICD) treated with oral procainamide or mexiletine for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) in two cardiology divisions between January 2010 and January 2020 were enrolled. Patients were divided into group A (oral procainamide) and group B (mexiletine) and the two groups were compared to each other. The primary endpoint was the efficacy of therapy; the secondary endpoint was the discontinuation of therapy. All events that occurred during procainamide or mexiletine treatment were compared with a matched duration period before the initiation of the therapy. Antiarrhythmic therapy was considered effective when a ≥80% reduction of the sustained ventricular arrhythmias burden recorded by the ICD was achieved. Results: A total of 68 consecutive patients (61 males, 89.7%; mean age 74 ± 10 years) were included in this retrospective analysis. After a median follow-up of 19 months, 38 (56%) patients had a significant reduction in the VA burden. After multivariable adjustment, therapy with procainamide was independently associated with an almost 3-fold higher efficacy on VA suppression compared to mexiletine (HR 2.54, 95% CI 1.06–6.14, p = 0.03). Only three patients (9%) treated with procainamide presented severe side effects (dyspnea or hypotension) requiring discontinuation of therapy compared with six patients (18%) treated with mexiletine who interrupted therapy because of severe side effects (p = 0.47). Conclusions: Compared to mexiletine, oral procainamide had a higher efficacy for the treatment of recurrent and refractory VAs, and showed a good profile of tolerability. [ABSTRACT FROM AUTHOR]

Purpose of Review: Ventricular arrhythmias (VAs) affect many patients with heart failure and underlying structural heart disease and are associated with significant morbidity and mortality. Antiarrhythmic drugs are often the initial treatment, but medication alone often fails to sufficiently suppress VAs. While catheter ablation (CA) remains the gold standard for treatment of VAs, CA is an invasive procedure and can be associated with periprocedural complications including acute clinical decompensation. Thus, there is an important need for alternative therapies. Recent Findings: Recent advances in risk stratification and the development of new ablation technologies may reduce some of the periprocedural complications and limitations of CA. In addition, less invasive therapies for VAs may provide an alternative treatment strategy for patients in both the acute and chronic setting. Summary: For patients acutely admitted with ventricular tachycardia electrical storm (VT-ES) or recurrent VT and cardiogenic shock, risk stratification tools have been developed to identify patients at high risk of acute hemodynamic decompensation during CA. These patients require a multidisciplinary approach and might need mechanical circulatory support (MCS) if CA is selected as the treatment strategy. Alternatively, less invasive therapies targeting the autonomic nervous system may be reasonable. In the chronic setting, developments in medical therapy have reduced the risk of sudden cardiac death in heart failure patients and stereotactic whole-body radiation (SBRT) has evolved as a potential, non-invasive therapy. Further research is needed to personalize VA therapy for individual patients. [ABSTRACT FROM AUTHOR]

Patients presenting with or alerting emergency networks due to acute heart failure (AHF) form a diverse group with a plethora of symptoms, risks, comorbidities, and aetiologies. During AHF, there is an increased risk of destabilizing the functional substrate and modulatory adding to the risk of ventricular arrhythmias (VAs) already created by the structural substrate. New VAs during AHF have previously identified patients with higher intra-hospital and 60-day morbidity and mortality. Risk stratification and criteria/best time point for coronary intervention and implantable cardioverter defibrillator implantation, however, are still controversial topics in this difficult clinical setting. The characteristics and logistics of pre-hospital emergency medicine, as well as the density of centres capable of treating AHF and VAs, differ massively throughout Europe. Scientific guidelines provide clear recommendations for the management of arrhythmias in patients with chronic heart failure. However, the incidence, significance, and management of arrhythmias in patients with AHF have been less studied. This consensus paper aimed to address the identification and treatment of VAs that complicate the course of patients who have AHF, including cardiogenic shock. [ABSTRACT FROM AUTHOR]

Background: The use of intravenous (IV) sotalol loading following recent U.S. Food and Drug Administration (FDA) approval of a 1-day loading protocol has reduced the obligatory 3-day hospital stay for sotalol initiation when given orally. Several studies have recently demonstrated the safety and feasibility of IV loading for patients with atrial arrhythmias. However, there is a paucity of data on the feasibility and safety of IV sotalol loading for patients with ventricular arrhythmias. This study aims to assess the safety, feasibility, and length of stay (LOS) outcomes of IV sotalol loading for the prevention of ventricular arrhythmias. Methods: A retrospective analysis was performed of all patients undergoing IV sotalol loading and oral sotalol initiation for ventricular arrhythmias, or IV sotalol loading for atrial arrhythmias between August 2021 and December 2023 at Northwestern University. Baseline characteristics, success of sotalol initiation/loading, changes in heart rate (HR) and QT/QTc, safety, and LOS were compared between patients undergoing sotalol loading/initiation for ventricular arrhythmias (IV vs. PO) and between patients undergoing IV sotalol loading for ventricular arrhythmias vs. for atrial arrhythmias. Results: A total of 28 patients underwent sotalol loading/initiation for ventricular arrhythmias (N = 15 IV and N = 13 PO) and 41 patients underwent IV sotalol loading for atrial arrhythmias. Baseline characteristics of congestive heart failure history and left ventricular ejection fraction were worse in the ventricular arrhythmias group. There was no significant difference in the successful completion of IV sotalol loading for ventricular arrhythmias compared to oral sotalol initiation for ventricular arrhythmias or IV sotalol loading for atrial arrhythmias (86.7% vs. 92.3% vs. 90.2%, p = 0.88). There was a significant increase in ΔQTc following IV sotalol infusion for ventricular arrhythmias compared to following PO sotalol initiation for ventricular arrhythmias (46.4 ± 29.2 ms vs. 8.9 ± 32.6 ms, p = 0.004) and following IV sotalol infusion for atrial arrhythmias (46.4 ± 29.2 ms vs. 24.0 ± 25.1 ms, p = 0.018). ΔHR following IV sotalol infusion for ventricular arrhythmias was similar to ΔHR following PO sotalol initiation for ventricular arrhythmias and ΔHR following IV sotalol infusion for atrial arrhythmias (− 7.5 ± 8.7 bpm vs. − 8.5 ± 13.9 bpm vs. − 8.3 ± 13.2 bpm, p = 0.87). There were no significant differences in discontinuation for QTc prolongation (6.7% vs. 1.7% vs. 2.4%, p = 0.64) and bradycardia (13.3% vs. 7.7% vs. 9.8%, p = 0.88) between IV sotalol loading for ventricular arrhythmias, PO sotalol initiation for ventricular arrhythmias, and IV sotalol loading for atrial arrhythmias. There were no instances of hypotension, life-threatening ventricular arrhythmias, heart failure, or death. Length of stay was significantly shorter for IV sotalol loading compared to PO sotalol initiation for ventricular arrhythmias (1.1 ± 0.36 days vs. 4.2 ± 1.0 days, p < 0.0001). Conclusion: IV sotalol loading appears feasible and safe for use in ventricular arrhythmias and results in a decreased length of stay. Despite increased comorbidities and greater increase in QTc interval following IV sotalol infusion in the ventricular arrhythmias group, there were no significant differences in successful completion of loading or adverse outcomes when compared to PO sotalol initiation for ventricular arrhythmias and IV loading for atrial arrhythmias. [ABSTRACT FROM AUTHOR]

Background: There have been limited data examining the temporal relationship between device-derived daily activity and ventricular arrhythmias (VAs). Objective: We aimed to assess whether activity predicted VAs or VAs predicted changes in activity. Methods: The CERTITUDE registry includes over 55,000 implanted devices active on Home Monitoring. Daily data on activity are captured by a 1-axis accelerometer. Temporal changes in activity during treated VAs were analyzed using the first event and 7-day activity windows (baseline, pre-event, and postevent). Baseline period was defined as 31 to 38 days prior to VA. VAs were categorized by heart rate (≤200 beats/min, >200 beats/min) and treatment (shock or antitachycardia pacing). Differences were assessed using the binomial proportion test and case-crossover analysis. Results: A total of 5631 devices (3688 implantable cardioverter-defibrillators, 1943 cardiac resynchronization therapy defibrillators) were analyzed with a cumulative follow-up duration of 18,354 years (5.6 million days). Patients with VA events >200 beats/min with shock (n = 593) had a significant decline in activity post-VA with a median –8.7% reduction (interquartile range –24.6% to 7.3%, P < 0.001). However, there was no reduction in activity before VA events >200 beats/min (P = .690) or before or after VA events >200 beats/min with antitachycardia pacing. However, VA events ≤200 beats/min with shock had reductions in activity following the event (–5.8%, interquartile range –29.5% to 12.3%, P = .003). Case-crossover analyses confirmed lower activity rates following for VA events >200 beats/min with shock. Conclusion: In the CERTITUDE registry, we have shown a temporal decline in device-derived activity following VA events >200 beats/min and for VA events

Abstract This case report presents a notable instance of subcutaneous implantable cardioverter defibrillator (S-ICD) implantation in a 9-year-old patient diagnosed with Timothy syndrome (TS), which is a rare condition characterized by mutations in the CACNA1c gene. Conventional therapies often have limited efficacy in managing TS. This case is significant, as it represents the youngest age for S-ICD implantation recorded in mainland China. While the absence of ventricular arrhythmias during hospitalization and follow-up is encouraging, it is not sufficient to conclusively establish the safety and feasibility of this intervention in young TS patients. Further research is needed to evaluate the long-term outcomes and to consider S-ICD as a potential standard treatment option for TS. Additionally, there is a need for a more detailed exploration of the molecular mechanisms underlying gene therapy and personalized interventions.

Abstract Background The association between the triglyceride-glucose (TyG) index and ventricular arrhythmias (VAs) is unclear. This study aimed to investigate the relationship between the TyG index, VAs, and major cardiovascular events in patients at high risk of sudden cardiac death (SCD). Methods We enrolled 1046 patients at high risk of SCD with an indication for implantable cardioverter-defibrillator (ICD) implantation at the Chinese National Center for Cardiovascular Diseases. The primary outcome was VAs, defined as sustained ventricular tachycardia and ventricular fibrillation documented by the ICD. The secondary outcomes were cardiac mortality, heart transplantation, and rehospitalization for heart failure. Results The mean (± SD) age was 59.6 ± 14.0 years old, and 25.7% were female. During the mean follow-up of 36.1 months, 342 (32.7%) patients had VAs, and 185 (17.7%) patients had major cardiovascular events. The mean fasting glucose and triglyceride levels were 111.9 ± 42.7 mg/dL and 140.0 ± 95.4 mg/L, respectively, with a TyG index range of 6.96–11.8. In the Fine-Gray subdistribution hazard model analysis, an increase in the TyG index was associated with a significant increase in the VAs (per 1 TyG index, hazard ratio [HR] 2.95; 95% confidence interval [CI], 2.29–3.80) and secondary outcome (HR 2.84; 95% CI 1.86–4.34). When stratified into tertiles, the risk of VAs was significantly higher in the highest tertile (HR 4.08; 95% CI, 2.81–5.92) than in the lowest tertile. Analysis of the secondary outcome revealed similar findings (HR 3.18; 95% CI, 1.73–5.85). Conclusions In our cohort, the pre-operational TyG index is significantly associated with VAs and major cardiovascular events for patients with high risk of SCD.

Reperfusion therapy in myocardial infarction patients with acute ST-segment elevation significantly reduced the frequency of ventricular tachycardia and ventricular fibrillation, however, such arrhythmias still occur in 6-8% of patients, posing a threat to their lives.The aim of the study was to determine the nature of ventricular arrhythmias occurring in myocardial infarction patients with acute ST-segment elevation within the first 24 hours after primary percutaneous coronary intervention, and their prognostic value regarding the development of complications during the inpatient treatment phase. The study involved 82 individuals (mean age: 62,4±10,2 years; male: 69,23 (58,6-78,92)%, female: 30,77 (21,08-41,4)%). Within 24 hours after the infarct-related artery stenting, all patients underwent a 24-hour Holter ECG monitoring. The course of the disease was analyzed based on the presence of risk factors such as hypertension, diabetes mellitus, past COVID-19, and obesity. Ventricular rhythm disturbances were represented mainly by premature contractions. They occurred significantly more frequently in patients with arterial hypertension (883,71 (96,0; 986.0); p=0,02; p=0,03; p=0,02, compared to patients with a history of COVID-19, diabetes, and obesity, respectively) and in those with past COVID-19 (711,3 (125,0; 846,5); p=0,01; p=0,04, compared to indi­viduals with diabetes and obesity, respectively). Isolated premature ventricular complexes, pairs, triplets were recorded, and in individuals with arterial hypertension and past COVID-19 “runs” of ventricular extrasystoles and episodes of nonsustained monomorphic and even polymorphic ventricular tachycardia, such as Torsades de Pointes, (under the condition of combined risk factors) were noted; predominantly in these patients during the hospital phase such сom­plications as ventricular fibrillation and asystole,with sudden cardiac arrest developed. The obtained results is an evidence of electrical myocardial instability and indicate that myocardial infarction patients with acute ST-segment elevation, in addition to myocardial revascularization, require optimization of pharmacological treatment. The use of intravenous beta-blockers as part of complex treatment prevented the occurrence of life-threatening ventricular arrhythmias during the inpatient treatment phase.

Background: Myotonic dystrophy type 1 (DM1) is associated with progressive conduction disease. Furthermore, DM1 patients are at risk ventricular arrhythmias (VAs), although prediction remains difficult. The 2022 Heart Rhythm Expert Consensus Statement gives a IIb recommendation to the use of electrophysiology study (EPS) to risk-stratify patients for VAs. The utility of EPS in predicting the development of VAs, however, has not been explored in this patient population. Objective: The study sought to examine the natural history of DM1 patients with positive and negative ventricular stimulation (v-stim) during EPS. Methods: Patients with a history of DM1 undergoing EPS with associated v-stim from 2008 to present were retrospectively identified. Results: From 2008 to 2022, 26 consecutive DM1 patients presented for EPS with v-stim. Four v-stim protocols were positive for sustained or hemodynamically significant ventricular tachycardia (VT), one of which was induced with 600 doubles, the others with triple extrastimuli. A total of 22 of 26 subjects received a device implant, with 18 receiving permanent pacemakers and 4 implantable cardioverter-defibrillators. All 4 of the patients with positive v-stims underwent ICD implantation. After a mean of 5.7 years of follow-up, 7 patients had sustained VT, 6 of whom had negative v-stims. Of the 4 patients with positive v-stims, only 1 developed sustained VT in follow-up. Other than baseline QT interval at time of EPS, no baseline characteristics were significantly different between patients with and without subsequent VT. Conclusion: In this single center, v-stim in DM1 patients did not predict clinical VAs, as a vast majority of DM1 patients who developed VAs had negative v-stims.

Background: Several reports exist of an acquired exercise-induced arrhythmogenic cardiomyopathy. Little is known about myocardial disease progression and arrhythmia prediction in this population. Objective: The study sought to explore the evolution of myocardial function and structure and its relation to incident life-threatening ventricular arrhythmias (VA), to identify markers of impending events. Methods: We included athletes (individuals with exercise doses >24 metabolic equivalent of task hours per week, >6 consecutive years, participating in organized and competitive sports) who had VA, absence of family history and known genetic variants associated with cardiac disease, and no other identified etiology, in a tertiary referral single-center, longitudinal cohort study of patients with exercise-induced arrhythmogenic cardiomyopathy (EiAC). Evolution of myocardial function and structure was assessed by repeated echocardiographic examinations during long-term follow-up. Life-threatening VA were assessed at baseline and during long-term follow-up. Results: Forty-one EiAC patients (15% women, age 45 ± 13 years) were followed for 80 (interquartile range 48–115) months. There were no changes in myocardial function or structure in the overall population during follow-up. We observed high incidence rate and high recurrence rate of life-threatening VA in EiAC patients. Subtle deterioration of right ventricular function was strongly associated with subsequent first-time VA (odds ratio 1.12, 95% confidence interval 1.01–1.25, P = .031, per 1% deterioration of right ventricular free wall longitudinal strain). Conclusion: There were no clear changes in myocardial function or structure during follow-up in the overall population, but there was a high incidence rate and high recurrence rate of life-threatening VA. Subtle right ventricular deterioration by free wall longitudinal strain was a strong predictor of impending first-time life-threatening VA during follow-up.

BACKGROUND: In severely affected patients with catecholaminergic polymorphic ventricular tachycardia, beta-blockers are often insufficiently protective. The purpose of this study was to evaluate whether flecainide is associated with a lower incidence of arrhythmic events (AEs) when added to beta-blockers in a large cohort of patients with catecholaminergic polymorphic ventricular tachycardia. METHODS: From 2 international registries, this multicenter case cross-over study included patients with a clinical or genetic diagnosis of catecholaminergic polymorphic ventricular tachycardia in whom flecainide was added to beta-blocker therapy. The study period was defined as the period in which background therapy (ie, beta-blocker type [beta1-selective or nonselective]), left cardiac sympathetic denervation, and implantable cardioverter defibrillator treatment status, remained unchanged within individual patients and was divided into pre-flecainide and on-flecainide periods. The primary end point was AEs, defined as sudden cardiac death, sudden cardiac arrest, appropriate implantable cardioverter defibrillator shock, and arrhythmic syncope. The association of flecainide with AE rates was assessed using a generalized linear mixed model assuming negative binomial distribution and random effects for patients. RESULTS: A total of 247 patients (123 [50%] females; median age at start of flecainide, 18 years [interquartile range, 14-29]; median flecainide dose, 2.2 mg/kg per day [interquartile range, 1.7-3.1]) were included. At baseline, all patients used a beta-blocker, 70 (28%) had an implantable cardioverter defibrillator, and 21 (9%) had a left cardiac sympathetic denervation. During a median pre-flecainide follow-up of 2.1 years (interquartile range, 0.4-7.2), 41 patients (17%) experienced 58 AEs (annual event rate, 5.6%). During a median on-flecainide follow-up of 2.9 years (interquartile range, 1.0-6.0), 23 patients (9%) experienced 38 AEs (annual event rate, 4.0%). There were significantly fewer AEs after initiation of flecainide (incidence rate ratio, 0.55 [95% CI, 0.38-0.83]; P=0.007). Among patients who were symptomatic before diagnosis or during the pre-flecainide period (n=167), flecainide was associated with significantly fewer AEs (incidence rate ratio, 0.49 [95% CI, 0.31-0.77]; P=0.002). Among patients with ≥1 AE on beta-blocker therapy (n=41), adding flecainide was also associated with significantly fewer AEs (incidence rate ratio, 0.25 [95% CI, 0.14-0.45]; P

Objectives: Elective electrical cardioversion (ECV) is frequently used for supraventricular tachycardia therapy. However, the success rate of this approach varies, and ventricular arrhythmias may develop as a consequence. We aimed to determine whether the timing of pre-ECV potassium serum testing affects patient outcomes. Materials and Methods: This retrospective cohort study analyzed 65 patients who underwent elective ECV in 2023. Patients were divided into two groups (short-interval vs long-interval) based on the median time (in days) between the potassium test and ECV. The primary outcome measure was the incidence of ventricular arrhythmias, whereas the secondary outcome measure was immediate restoration of sinus rhythm. Results: The median time between the potassium test and ECV was 57 (interquartile range 135) days. No ventricular arrhythmias were observed. There was no statistically significant difference in success rates between the two groups (84.8% versus 84.4%; p=0.958; χ2 test). Predetermined risk factors for potassium disturbances did not influence success rates. Conclusion: Our study suggests that the timing of potassium serum testing does not influence the occurrence of ventricular arrhythmias following elective ECV. In addition, the timing of serum potassium testing did not influence the success rate. Therefore, potassium testing shortly before cardioversion may not be necessary.

Background: Long QT syndrome (LQTS) is a rare cardiac disorder characterized by prolonged ventricular repolarization and increased risk of ventricular arrhythmias. This review summarizes current knowledge of LQTS pathogenesis and treatment strategies. Objectives: The purpose of this study was to provide an in-depth understanding of LQTS genetic and molecular mechanisms, discuss clinical presentation and diagnosis, evaluate treatment options, and highlight future research directions. Methods: A systematic search of PubMed, Embase, and Cochrane Library databases was conducted to identify relevant studies published up to April 2024. Results: LQTS involves mutations in ion channel–related genes encoding cardiac ion channels, regulatory proteins, and other associated factors, leading to altered cellular electrophysiology. Acquired causes can also contribute. Diagnosis relies on clinical history, electrocardiographic findings, and genetic testing. Treatment strategies include lifestyle modifications, β-blockers, potassium channel openers, device therapy, and surgical interventions. Conclusion: Advances in understanding LQTS have improved diagnosis and personalized treatment approaches. Challenges remain in risk stratification and management of certain patient subgroups. Future research should focus on developing novel pharmacological agents, refining device technologies, and conducting large-scale clinical trials. Increased awareness and education are crucial for early detection and appropriate management of LQTS.

Abstract Background Idiopathic ventricular arrhythmias (IVAs) arising from different portions of the communicating vein of the left ventricular summit (summit-CV) are not a rare phenomenon. Whereas its electrocardiographic (ECG) and electrophysiological characteristics are not fully investigated. Objective This study aimed to identify distinct ECG and electrophysiological features of IVAs originating from different portions of summit-CV. Methods Nineteen patients confirmed arising from summit-CV were included in this study. Results The 19 patients were divided into proximal and distal portion groups based on their target sites in summit-CV. In the proximal portion group, 100% (11/11) VAs showed dominant negative (rs or QS) waves in lead I, while in the distal portion group, 87.5% (7/8) showed dominant positive waves (R, Rs or r) (p 4mV, SI3.5mV, RI/SI>0.83, and RV1/SV1< 2.6 indicated a distal portion of summit-CV with the predictive value of 0.909, 1.000, 0.653, 0.972, 0.903, 0.966, respectively. A more positive wave in lead I and a more negative wave in lead V1 indicated more distal origin in summit-CV. Target sites in proximal and distal summit-CV groups showed similar electrophysiological characteristics during mapping. Conclusions There were significant differences in ECG characteristics of VAs at different portions of summit-CV, which could aid pre-procedure planning and facilitate radiofrequency catheter ablation (RFCA) procedures.

Background: The aim of this study is to report on the genetic composition of Brugada syndrome (BrS) patients undergoing genetic testing in Hong Kong. Methods: Patients with suspected BrS who presented to the Hospital Authority of Hong Kong between 1997 and 2019, and underwent genetic testing, were analyzed retrospectively. Results: A total of 65 subjects were included (n = 65, 88% male, median presenting age 42 [30-54] years old, 58% type 1 pattern). Twenty-two subjects (34%) showed abnormal genetic test results, identifying the following six novel, pathogenic or likely pathogenic mutations in SCN5A: c.674G > A, c.2024-11T > A, c.2042A > C, c.4279G > T, c.5689C > T, c.429del. Twenty subjects (31%) in the cohort suffered from spontaneous ventricular tachycardia/ventricular fibrillation (VT/VF) and 18 (28%) had incident VT/VF over a median follow-up of 83 [Q1-Q3: 52-112] months. Univariate Cox regression demonstrated that syncope (hazard ratio [HR]: 4.27 [0.95-19.30]; P = 0.059), prior VT/VF (HR: 21.34 [5.74-79.31; P < 0.0001) and T-wave axis (HR: 0.970 [0.944-0.998]; P = 0.036) achieved P < 0.10 for predicting incident VT/VF. After multivariate adjustment, only prior VT/VF remained a significant predictor (HR: 12.39 [2.97-51.67], P = 0.001). Conclusion: This study identified novel mutations in SCN5A in a Chinese cohort of BrS patients. [ABSTRACT FROM AUTHOR]

Young (<18 years of age) patients with Brugada syndrome (BrS) are often under-represented in BrS studies and their management, especially related to syncopal episodes, remains unclear. This study sought to describe the arrhythmia prevalence among young patients with BrS undergoing continuous rhythm monitoring by implantable loop recorder (ILR) and to assess the etiology behind syncope of undetermined origin. A total of 147 patients with BrS with ILR were enrolled in 12 international centers and divided into pediatric (age <12 years; n = 77, 52%) and adolescents (age 13-18 years; n = 70, 48%). Mean age was 11.3 years, 53 patients (36.1%) were female, and 31 (21.1%) had spontaneous type 1 electrocardiograms. Over a median follow-up of 3.6 years (Q1-Q3: 1.6-4.8 years), an arrhythmic event was recorded in 33 patients (22.4%), mainly of nonventricular origin: 15 atrial (10.2%) and 16 bradyarrhythmic events (10.9%). Ventricular arrhythmias occurred in 4 patients, all with spontaneous BrS, and were fever-related in one-half. Among all patients with recurrence of syncope during follow-up, true arrhythmic syncope was documented in 5 (17.8%), and it was due to bradyarrhythmias or atrial arrhythmias in 3 cases (60%). Continuous rhythm monitoring with ILRs in young patients with BrS detects a broad range of arrhythmias. Ventricular arrhythmias occur predominantly in patients with spontaneous type 1 electrocardiograms and during fever. Despite the young age, bradyarrhythmias and atrial arrhythmias are frequent and represent the cause of arrhythmic syncope in 60% of patients. Young patients with BrS with syncope of undetermined origin may benefit from ILR implant. [ABSTRACT FROM AUTHOR]

AIM: To examine how the variation of the β1-adrenergic receptor gene affects the occurrence of ventricular arrhythmias and the prognosis over a 6-month period in individuals suffering from acute ST-segment elevation myocardial infarction (STEMI). METHODS: A study was conducted retrospectively, where patients diagnosed STEMI and treated at Yunfu City People's Hospital between January 2021 and February 2023 were included based on predefined criteria. The patients were then divided into three groups according to their genotypes of the β1-adrenergic receptor Arg389Gly gene polymorphism: CC group (Arg389Arg), CG group (Arg389Gly), and GG group (Gly389Gly). Discrepancies in initial clinical data upon admission [such as Killip classification, heart rate, systolic and diastolic blood pressure, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter (LVDD), and serum tumor necrosis factor alpha (TNF-α), N-terminal pro-B-type natriuretic peptide (NT-proBNP), creatine kinase MB (CK-MB) and high-sensitivity C-reactive protein (hs-CRP) ], and outcomes gathered during a 6-month follow-up via telephone after discharge (heart rate, NT-proBNP, CK-MB, LVEF, LVDD, and occurrences of major adverse cardiac events) were compared across the three groups. RESULTS: The study enrolled a total of 178 STEMI patients with ventricular arrhythmias, comprising 87 cases in CC group (48. 9%), 73 cases in CG group (41. 0%), and 18 cases in GG group (10. 1%). There were no notable variances in demographic characteristics such as age, sex, weight, BMI, smoking history, alcohol consumption history, comorbidities, blood pressure, heart rate, Killip classification (III amd IV), TNF-α, NT-proBNP, CK-MB, hs-CRP, LVEF and LVDD across the three groups (P>0. 05). Following a 6-month monitoring period, the cardiac function parameters in CG and GG groups exhibited significant improvement compared to those in CC group (P<0. 05), with noteworthy lower levels of NT-proBNP and CK-MB in GG group in contrast to CG group (P<0. 05). Notably, there were significant discrepancies in the incidence of major adverse cardiac events during the follow-up period among the study groups, with 17 cases in CC group (19. 5%), 5 cases in CG group (6. 9%), and 1 case in GG group (5. 6%) (χ²=6. 887, P<0. 05). CONCLUSION: There is no correlation between the severity of STEMI accompanied by ventricular arrhythmias and the β1-adrenergic receptor Arg389Gly gene polymorphism. However, this gene variant is connected with enhancements in cardiac function and short-term prognosis post-treatment. [ABSTRACT FROM AUTHOR]

Ranolazine is an anti-anginal medication that has demonstrated antiarrhythmic properties by inhibiting both late sodium and potassium currents. Studies have shown promising results for ranolazine in treating both atrial fibrillation and ventricular arrhythmias, particularly when used in combination with other medications. This review explores ranolazine's mechanisms of action and its potential role in cardiac arrhythmias treatment in light of previous clinical studies. [ABSTRACT FROM AUTHOR]

Historically, patients with myocarditis were considered for implantable cardioverter defibrillator (ICD) utilization only in the chronic phase of the disease following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease, challenging the long-standing perception that this disease process was largely reversible. Given this changing environment of information, the latest US and European guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. Additionally, several studies with small subgroups of patients have demonstrated a possible benefit of wearable cardioverter defibrillators (WCDs) in this patient demographic. Assuming that larger studies confirm their utility, it is possible that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation, while providing temporary protection for a small percentage of patients before the development of a major arrhythmic event. This review ultimately serves as a comprehensive review of the most recent guidelines for defibrillator use in acute and chronic myocarditis. The latest US and European guidelines support ICD use for myocarditis patients following the development of persistent cardiomyopathy refractory to medical therapy or occurrence of a major ventricular arrhythmic event. Previously, patients in the acute phase were excluded from ICD utilization even after experiencing malignant ventricular tachycardia or ventricular fibrillation due to the long-standing perception that this disease process was largely reversible. However, recent literature has indicated that ventricular arrhythmias are frequently reported even in the acute phase of the disease. Additionally, we found that the myocardial damage that is inflicted persists many years after the initial episode. Given this changing environment of information, guidelines were recently updated in 2022 to now consider ICD implantation during the acute phase which has significantly increased the number of individuals eligible for these devices. We support possible ICD utilization for secondary prevention during the acute phase of myocarditis given the elevated risk of arrhythmia recurrence and the fact that any ventricular arrhythmia can induce sudden cardiac death. Future prospective studies are needed to assess which patients may benefit most from early ICD implantation. WCDs have improved survival in patient populations at high-risk for sudden cardiac death who are not candidates for ICD implantation. After analyzing several recent studies with small subgroups of patients, WCDs appear to demonstrate similar efficacy for myocarditis patients as well. Assuming that larger studies confirm their utility, we believe that WCDs can assist in detection of ventricular arrhythmias and selection of high-risk candidates for ICD implantation. Furthermore, WCDs have the additional benefit of acting as primary prevention by providing temporary protection for a small percentage of myocarditis patients before they develop a major arrhythmic event. [Display omitted] • Myocarditis can lead to ventricular arrhythmias including sudden cardiac death. • Currently, implantable cardioverter defibrillators (ICDs) are indicated for primary prevention in select myocarditis patients. • ICD indications expanded as secondary prevention in acute and chronic myocarditis. • Wearable cardioverter defibrillators can bridge patients to an ICD to protect against life-threatening arrhythmias. [ABSTRACT FROM AUTHOR]

Background: Catheter ablation (CA) is a well-established treatment in patients with ventricular tachycardia and appropriate implantable cardioverter defibrillator (ICD) therapies. Methods: We enrolled 57 consecutive carriers of ICD undergoing CA for electrical storm (ES). Our aim was to investigate differences in clinical, device-related, and electroanatomic features among patients who had history of appropriate ICD interventions before the ES compared to those who had not. The primary endpoint was a composite of death from any cause and recurrences of sustained VT, ventricular fibrillation, appropriate ICD therapy, or ES. Results: During a median follow up of 39 months, 28 patients (49%) met the primary endpoint. Those with previous ICD interventions had a higher prevalence of late potentials and a greater unipolar low-voltage area at electroanatomic mapping. Patients who met the primary endpoint had a higher prevalence of ATP/shock episodes preceding the ES event. At Cox regression analysis, non-ischemic dilated cardiomyopathy (NIDCM), QRS duration, and previous ATP and/or shock before the ES were associated with arrhythmic recurrences and/or death. At multivariate analysis, NIDCM and previous shock were associated with arrhythmic recurrences and/or death. Conclusions: A history of recurrent ICD therapies predicts worse outcomes when CA is needed because of ES. Although more studies are needed to definitively address this question, our data speak in support of an early referral for CA of ES. [ABSTRACT FROM AUTHOR]

Background: Idiopathic ventricular arrhythmias (IVAs) arising from different portions of the communicating vein of the left ventricular summit (summit-CV) are not a rare phenomenon. Whereas its electrocardiographic (ECG) and electrophysiological characteristics are not fully investigated. Objective: This study aimed to identify distinct ECG and electrophysiological features of IVAs originating from different portions of summit-CV. Methods: Nineteen patients confirmed arising from summit-CV were included in this study. Results: The 19 patients were divided into proximal and distal portion groups based on their target sites in summit-CV. In the proximal portion group, 100% (11/11) VAs showed dominant negative (rs or QS) waves in lead I, while in the distal portion group, 87.5% (7/8) showed dominant positive waves (R, Rs or r) (p < 0.000). In lead V1, 100% (11/11) of the proximal portion group showed dominant positive waves (R or Rs), while 62.50% (5/8) of the distal portion group showed positive and negative bidirectional or negative waves (RS or rS) (p < 0.005). RI>4mV, SI<3.5mV, RV1<13mV, SV1>3.5mV, RI/SI>0.83, and RV1/SV1< 2.6 indicated a distal portion of summit-CV with the predictive value of 0.909, 1.000, 0.653, 0.972, 0.903, 0.966, respectively. A more positive wave in lead I and a more negative wave in lead V1 indicated more distal origin in summit-CV. Target sites in proximal and distal summit-CV groups showed similar electrophysiological characteristics during mapping. Conclusions: There were significant differences in ECG characteristics of VAs at different portions of summit-CV, which could aid pre-procedure planning and facilitate radiofrequency catheter ablation (RFCA) procedures. [ABSTRACT FROM AUTHOR]

Aim: Arrhythmic complications in patients with acute coronary syndromes during hospitalization are not uncommon in cardiology practice. In our retrospective study, we investigated the effect of primary ventricular arrhythmias occurring within the first 48 hours from the time of hospitalization on cardiovascular mortality and resuscitated cardiopulmonary arrest in patients with ST-segment elevation myocardial infarction. Introduction: Although the rate of myocardial infarction has decreased over the years, it is responsible for hundreds of thousands of deaths worldwide. Arrhythmic complications take an essential place for morbidity and mortality in the course of myocardial infarction. Ventricular arrhythmias play a pivotal role in terms of mortality in acute terms of myocardial infarction. Material and Method: In our single center and retrospective study, 18-year-old and older patients who presented to Sağlik Bilimleri University Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital emergency department with ischemic symptoms and were admitted to hospital with the diagnose of ST-segment elevation myocardial infarction were enrolled. The primary endpoint was in-hospital mortality and resuscitated cardiopulmonary arrest. Results: 1,137 patients were included in the study. Primary VT/VF which occurred within the first 48 hours from the time of hospitalization was observed in 8.2% of patients (n: 93). Previous MI history (3.47 OR, 95% CI 1.41–8.55 p=0.0068, LASSO: 0.388), KILLIP class at the time of admission (1.52 OR, 95% CI 0.94–2.45 p=0.0813, LASSO: 0.627), Primary VT/VF (4.02 OR, 95% CI 1.44–11.21 p=0.0077, LASSO: 0.440), left ventricle ejection fraction calculated by transthoracic echocardiography (0.88 OR, 95% CI 0.78–0.99 p=0.0444, LASSO: -0.032) and serum CRP level (1.81 OR, 95% CI 0.22–14.53 p=0.57, LASSO: 0.036) were independent predictors of MACE including in-hospital mortality and resuscitated cardiopulmonary arrest. Conclusion: Primary VT and VF are independent predictors of in-hospital mortality and resuscitated cardiopulmonary arrest events in patients with ST-segment elevation acute MI. [ABSTRACT FROM AUTHOR]

Mitral valve prolapse is a common valve disorder that usually has a benign prognosis unless there is significant regurgitation or LV impairment. However, a subset of patients are at an increased risk of ventricular arrhythmias and sudden cardiac death, which has led to the recognition of "arrhythmic mitral valve prolapse" as a clinical entity. Emerging risk factors include mitral annular disjunction and myocardial fibrosis. While echocardiography remains the primary method of evaluation, cardiac magnetic resonance has become crucial in managing this condition. Cine magnetic resonance sequences provide accurate characterization of prolapse and annular disjunction, assessment of ventricular volumes and function, identification of early dysfunction and remodeling, and quantitative assessment of mitral regurgitation when integrated with flow imaging. However, the unique strength of magnetic resonance lies in its ability to identify tissue changes. T1 mapping sequences identify diffuse fibrosis, in turn related to early ventricular dysfunction and remodeling. Late gadolinium enhancement sequences detect replacement fibrosis, an independent risk factor for ventricular arrhythmias and sudden cardiac death. There are consensus documents and reviews on the use of cardiac magnetic resonance specifically in arrhythmic mitral valve prolapse. However, in this article, we propose an algorithm for the broader use of cardiac magnetic resonance in managing this condition in various scenarios. Future advancements may involve implementing techniques for tissue characterization and flow analysis, such as 4D flow imaging, to identify patients with ventricular dysfunction and remodeling, increased arrhythmic risk, and more accurate grading of mitral regurgitation, ultimately benefiting patient selection for surgical therapy. [ABSTRACT FROM AUTHOR]

Obesity is a chronic disease that is rapidly increasing in prevalence and affects more than 600 million adults worldwide, and this figure is estimated to increase by at least double by 2030. In the United States, more than one-third of the adult population is either overweight or obese. The global obesity epidemic is a major risk factor for the development of life-threatening arrhythmias occurring in patients with long QT, particularly in conditions where multiple heart-rate-corrected QT-interval-prolonging mechanisms are simultaneously present. In obesity, excess dietary fat in adipose tissue stimulates the release of immunomodulatory cytokines such as interleukin (IL)-6, leading to a state of chronic inflammation in patients. Over the last decade, increasing evidence has been found to support IL-6 signaling as a powerful predictor of the severity of heart diseases and increased risk for ventricular arrhythmias. IL-6′s pro-inflammatory effects are mediated via trans-signaling and may represent a novel arrhythmogenic risk factor in obese hearts. The first selective inhibitor of IL-6 trans-signaling, olamkicept, has shown encouraging results in phase II clinical studies for inflammatory bowel disease. Nevertheless, the connection between IL-6 trans-signaling and obesity-linked ventricular arrhythmias remains unexplored. Therefore, understanding how IL-6 trans-signaling elicits a cellular pro-arrhythmic phenotype and its use as an anti-arrhythmic target in a model of obesity remain unmet clinical needs. [ABSTRACT FROM AUTHOR]

Many patients with mildly to moderately reduced left ventricular ejection fraction (LVEF) who require permanent pacemaker (PPM) implantation do not have a concurrent indication for implantable cardioverter-defibrillator (ICD) therapy. However, the risk of ventricular tachycardia/ventricular fibrillation (VT/VF) in this population is unknown. The aim of this study was to describe the risk of VT/VF after PPM implantation in patients with mildly to moderately reduced LVEF. Retrospective analysis was performed of 243 patients with LVEF between 35% and 49% who underwent PPM placement and did not meet indications for an ICD. The primary end point was occurrence of sustained VT/VF. Competing risks regression was performed to calculate subhazard ratios for the primary end point. Median follow-up was 27 months; 73% of patients were male, average age was 79 ± 10 years, average LVEF was 42% ± 4%, and 70% were New York Heart Association class II or above. Most PPMs were implanted for sick sinus syndrome (34%) or atrioventricular block (50%). Of 243 total patients, 11 (4.5%) met the primary end point of VT/VF. Multivessel coronary artery disease (CAD) was associated with significantly higher rates of VT/VF, with a subhazard ratio of 5.4 (95% CI, 1.5–20.1; P =.01). Of patients with multivessel CAD, 8 of 82 (9.8%) patients met the primary end point for an annualized risk of 4.3% per year. Patients with mildly to moderately reduced LVEF and multivessel CAD undergoing PPM implantation are at increased risk for the development of malignant ventricular arrhythmias. Patients in this population may benefit from additional risk stratification for VT/VF and consideration for upfront ICD implantation. [ABSTRACT FROM AUTHOR]

Aims Patients undergoing catheter ablation (CA) of ventricular arrhythmias (VAs) are generally observed overnight in the hospital given the concern for complications. To evaluate the efficacy and safety of same-day discharge (SDD) of patients undergoing elective CA of premature ventricular complexes (PVCs). Methods and results A retrospective evaluation of all patients undergoing elective VA ablation at Ascension St Vincent Hospital from 1 January 2018 to 31 December 2019 was undertaken. Of those, the patients undergoing PVC ablation were divided into SDD and non-SDD. Patients underwent SDD at the discretion of the operator. The primary safety outcome was the 30-day incidence of complications and death. The primary efficacy outcome was procedural success. Among 188 patients who underwent VA ablation, 98 (52.1%) were PVC ablations, and of those, 55 (56.1%) were SDD. There was no difference in age, gender, comorbidities, or ejection fraction between the two groups. Patients that were non-SDD were more likely to be on chronic anticoagulation (P = 0.03), have ablation in the LV (P = 0.04), have retrograde access (P = 0.03), and receive heparin during the procedure (P = 0.01). There were no complications in the SDD group compared with one (2.3%) in the non-SDD group. There was no difference in primary efficacy between the two groups with a 90.9% acute success in the SDD and 88.4% in the non-SDD (P = 0.68). Conclusion Same-day discharge for CA of PVCs is feasible and could lower healthcare resource utilization without compromising outcomes in this unique population. [ABSTRACT FROM AUTHOR]

Background and Aims Risk scores are proposed for genetic arrhythmias. Having proposed in 2010 one such score (M-FACT) for the long QT syndrome (LQTS), this study aims to test whether adherence to its suggestions would be appropriate. Methods LQT1/2/3 and genotype-negative patients without aborted cardiac arrest (ACA) before diagnosis or cardiac events (CEs) below age 1 were included in the study, focusing on an M-FACT score ≥2 (intermediate/high risk), either at presentation (static) or during follow-up (dynamic), previously associated with 40% risk of implantable cardioverter defibrillator (ICD) shocks within 4 years. Results Overall, 946 patients (26 ± 19 years at diagnosis, 51% female) were included. Beta-blocker (βB) therapy in 94% of them reduced the rate of those with a QTc ≥500 ms from 18% to 12% (P <.001). During 7 ± 6 years of follow-up, none died; 4% had CEs, including 0.4% with ACA. A static M-FACT ≥2 was present in 110 patients, of whom 106 received βBs. In 49/106 patients with persistent dynamic M-FACT ≥2, further therapeutic optimization (left cardiac sympathetic denervation in 55%, mexiletine in 31%, and ICD at 27%) resulted in just 7 (14%) patients with CEs (no ACA), with no CEs in the remaining 57. Additionally, 32 patients developed a dynamic M-FACT ≥2 but, after therapeutic optimization, only 3 (9%) had C Es. According to an M-FACT score ≥2, a total of 142 patients should have received an ICD, but only 22/142 (15%) were implanted, with shocks reported in 3. Conclusions Beta-blockers often shorten QTc, thus changing risk scores and ICD indications for primary prevention. Yearly risk reassessment with therapy optimization leads to fewer ICD implants (3%) without increasing life-threatening events. [ABSTRACT FROM AUTHOR]

Introduction: Ventricular unloading during prolonged bed rest, mechanical circulatory support or microgravity has repeatedly been linked to potentially life-threatening arrhythmias. It is unresolved, whether this arrhythmic phenotype is caused by the reduction in cardiac workload or rather by underlying diseases or external stimuli. We hypothesized that the reduction in cardiac workload alone is sufficient to impair ventricular repolarization and to induce arrhythmias in hearts. Methods: Rat hearts were unloaded using the heterotopic heart transplantation. The ECG of unloaded and of control hearts were telemetrically recorded over 56 days resulting in >5x106 cardiac cycles in each heart. Long-term electrical remodeling was analyzed using a novel semi-automatic arrhythmia detection algorithm. Results: 56 days of unloading reduced left ventricular weight by approximately 50%. While unloading did not affect average HRs, it markedly prolonged the QT interval by approximately 66% and induced a median tenfold increase in the incidence of ventricular arrhythmias in comparison to control hearts. Conclusion: The current study provides direct evidence that the previously reported hypertrophic phenotype of repolarization during cardiac unloading translates into an impaired ventricular repolarization and ventricular arrhythmias in vivo. This supports the concept that the reduction in cardiac workload is a causal driver of the development of arrhythmias during ventricular unloading. [ABSTRACT FROM AUTHOR]

Reperfusion therapy in myocardial infarction patients with acute ST-segment elevation significantly reduced the frequency of ventricular tachycardia and ventricular fibrillation, however, such arrhythmias still occur in 6-8% of patients, posing a threat to their lives. The aim of the study was to determine the nature of ventricular arrhythmias occurring in myocardial infarction patients with acute ST-segment elevation within the first 24 hours after primary percutaneous coronary intervention, and their prognostic value regarding the development of complications during the inpatient treatment phase. The study involved 82 individuals (mean age: 62,4±10,2 years; male: 69,23 (58,6-78,92)%, female: 30,77 (21,08-41,4)%). Within 24 hours after the infarct-related artery stenting, all patients underwent a 24-hour Holter ECG monitoring. The course of the disease was analyzed based on the presence of risk factors such as hypertension, diabetes mellitus, past COVID-19, and obesity. Ventricular rhythm disturbances were represented mainly by premature contractions. They occurred significantly more frequently in patients with arterial hypertension (883,71 (96,0; 986.0); p=0,02; p=0,03; p=0,02, compared to patients with a history of COVID-19, diabetes, and obesity, respectively) and in those with past COVID-19 (711,3 (125,0; 846,5); p=0,01; p=0,04, compared to individuals with diabetes and obesity, respectively). Isolated premature ventricular complexes, pairs, triplets were recorded, and in individuals with arterial hypertension and past COVID-19 “runs” of ventricular extrasystoles and episodes of nonsustained monomorphic and even polymorphic ventricular tachycardia, such as Torsades de Pointes, (under the condition of combined risk factors) were noted; predominantly in these patients during the hospital phase such сomplications as ventricular fibrillation and asystole,with sudden cardiac arrest developed. The obtained results is an evidence of electrical myocardial instability and indicate that myocardial infarction patients with acute ST-segment elevation, in addition to myocardial revascularization, require optimization of pharmacological treatment. The use of intravenous beta-blockers as part of complex treatment prevented the occurrence of life-threatening ventricular arrhythmias during the inpatient treatment phase. [ABSTRACT FROM AUTHOR]

Objectives Elective electrical cardioversion (ECV) is frequently used for supraventricular tachycardia therapy. However, the success rate of this approach varies, and ventricular arrhythmias may develop as a consequence. We aimed to determine whether the timing of pre-ECV potassium serum testing affects patient outcomes. Materials and Methods This retrospective cohort study analyzed 65 patients who underwent elective ECV in 2023. Patients were divided into two groups (short-interval vs long-interval) based on the median time (in days) between the potassium test and ECV. The primary outcome measure was the incidence of ventricular arrhythmias, whereas the secondary outcome measure was immediate restoration of sinus rhythm. Results The median time between the potassium test and ECV was 57 (interquartile range 135) days. No ventricular arrhythmias were observed. There was no statistically significant difference in success rates between the two groups (84.8% versus 84.4%; p=0.958; χ2 test). Predetermined risk factors for potassium disturbances did not influence success rates. Conclusion Our study suggests that the timing of potassium serum testing does not influence the occurrence of ventricular arrhythmias following elective ECV. In addition, the timing of serum potassium testing did not influence the success rate. Therefore, potassium testing shortly before cardioversion may not be necessary. Keywords:Electrical cardioversion, potassium, ventricular arrhythmias, serum testing: [ABSTRACT FROM AUTHOR]

Background Some patients affected by mitral valve (MV) prolapse (MVP) are at higher risk of ventricular arrhythmias (VAs), but the underlying pathogenesis, as well as the effects of surgery on VA, remain not fully understood. Mitral valve repair, however, represents a privileged point of view to deepen the understanding of arrhythmogenesis in this context. Hence, we report an interesting case of MV re-repair. Case summary A 52-year-old man was referred to our institution for severe mitral regurgitation (MR) due to P2 prolapse in the context of myxomatous MV degeneration. Pre-operative imaging showed systolic mitral annular disjunction, left ventricular (LV) wall curling, Pickelhaube's sign, and a prolapsing tricuspid valve (TV) with only mild regurgitation. Twenty-four-hour electrocardiogram (ECG) Holter revealed a significant burden of premature ventricular contractions (PVCs), most of them originating from anterior papillary muscle (APM), posterior papillary muscle (PPM), and mitral annulus (MA). Quadrangular resection of P2 and mitral annuloplasty were performed. One year later, relapse of severe MR due to a residual P2M1 prolapse occurred. Twenty-four-hour ECG Holter showed no PVCs from PPM and MA, while those from APM persisted. A central edge-to-edge repair was effectively used to fix the residual prolapse. After 1 year from REDO surgery, a third ECG Holter confirmed the absence of any remaining LV PVCs, but still few ectopic beats originating from TV were recorded. Discussion Here, we report a case of VA resolution after specific, anatomical triggers addressing surgical gestures. Our experience confirms that MV surgery may have a role in MVP patients' arrhythmias correction. [ABSTRACT FROM AUTHOR]

BackgroundCardioneuroablation (CNA) is an attractive treatment for vasovagal syncope. Its long-term efficacy and safety remain unknown. ObjectiveTo develop a chronic porcine model of CNA to examine ventricular tachyarrhythmia (VT/VF) susceptibility and cardiac autonomic function after CNA.MethodsA percutaneous CNA model was developed by ablation of left- and right-sided ganglionated plexi (GP)(n=5), confirmed by histology. Reproducible bilateral vagal denervation was confirmed following CNA by extracardiac vagal nerve stimulation (ECVNS) and histology. Chronic studies included 16 pigs randomized to CNA (n=8) and sham ablation (n=8). After 6 weeks, animals underwent hemodynamic studies, assessment of cardiac sympathetic and parasympathetic function using sympathetic chain stimulation (SCS) and direct VNS respectively, and proarrhythmic potential following left anterior descending coronary artery (LAD) ligation.ResultsAfter CNA, ECVNS responses remained abolished for 6 weeks despite ganglia remaining in ablated GPs. In the CNA group, direct VNS resulted in paradoxical increases in blood pressure, but not in sham animals (CNA group vs. sham: 8.36±7.0% vs. -4.83±8.7%, respectively, p=0.009). Left SCS (8Hz) induced significant QTc prolongation in the CNA group vs. sham (11.23±4.0% vs. 1.49±4.0%, respectively, p

PurposeCardiac autonomic dysfunction is one of the main pillars of cardiovascular pathophysiology. The purpose of this review is to provide an overview of the current state of the art on the pathological remodeling that occurs within the autonomic nervous system with cardiac injury and available neuromodulatory therapies for autonomic dysfunction in heart failure.MethodsData from peer-reviewed publications on autonomic function in health and after cardiac injury are reviewed. The role of and evidence behind various neuromodulatory therapies both in preclinical investigation and in-use in clinical practice are summarized.ResultsA harmonic interplay between the heart and the autonomic nervous system exists at multiple levels of the neuraxis. This interplay becomes disrupted in the setting of cardiovascular disease, resulting in pathological changes at multiple levels, from subcellular cardiac signaling of neurotransmitters to extra-cardiac, extra-thoracic remodeling. The subsequent detrimental cycle of sympathovagal imbalance, characterized by sympathoexcitation and parasympathetic withdrawal, predisposes to ventricular arrhythmias, progression of heart failure, and cardiac mortality. Knowledge on the etiology and pathophysiology of this condition has increased exponentially over the past few decades, resulting in a number of different neuromodulatory approaches. However, significant knowledge gaps in both sympathetic and parasympathetic interactions and causal factors that mediate progressive sympathoexcitation and parasympathetic dysfunction remain.ConclusionsAlthough our understanding of autonomic imbalance in cardiovascular diseases has significantly increased, specific, pivotal mediators of this imbalance and the recognition and implementation of available autonomic parameters and neuromodulatory therapies are still lagging.

IntroductionCardiac sarcoidosis (CS) is an increasingly recognized cause of cardiac disease. Because the clinical presentation of CS is non-specific, the diagnosis is often delayed. Early detection is essential to initiate treatments that reduce the risk of heart failure (HF) and arrhythmic death. We therefore aimed to describe the features of CS hospitalizations during which the initial diagnosis of CS is made.MethodsWe performed a retrospective analysis of hospitalizations from 2016 to 2019 in the Nationwide Readmission Database (NRD). Hospitalizations with a primary diagnosis suggestive of CS (HF/cardiomyopathy, cardiac arrest, arrhythmias, or heart block) were categorized into cases with and without CS as a secondary diagnosis (CS+ and CS−, respectively). One-to-one propensity score matching (PSM) was performed.ResultsThe CS+ cohort comprised 1,146 hospitalizations and the CS− cohort 3,250,696 hospitalizations. The CS+ cohort included patients who were younger and more often male. PSM resulted in highly matched cohorts (absolute standardized mean difference

BackgroundElectrocardiographic markers differentiating between death caused by ventricular arrhythmias and non-arrhythmic death could improve the selection of patients for implantable cardioverter-defibrillator (ICD) implantation. QRS fragmentation (fQRS) is a parameter of interest, but subject to debate. We investigated the association of an automatically quantified probability of fragmentation with the outcome in ICD patients.MethodsFrom a single-center retrospective registry, all patients implanted with an ICD between January 1996 and December 2018 were eligible for inclusion. Patients with active pacing were excluded. From the electronical medical record, clinical characteristics at implantation were collected and a 12-lead ECG was exported and analyzed by a previously validated machine-learning algorithm to quantify the probability of fQRS. To compare fQRS(+) and fQRS(−) patients, dichotomization was performed using the Youden index. Patients with a high probability of fragmentation in any region (anterior, inferior or lateral), were labeled fQRS(+). The impact of this fQRS probability on outcomes was investigated using Cox regression.ResultsA total of 1,242 patients with a mean age of 62.6 ± 11.5 years and a reduced left ventricular ejection fraction of 31 ± 12% were included of which 227 (18.3%) were female. The vast majority suffered from ischemic heart disease (64.3%) and were implanted in primary prevention (63.8%). 538 (43.3%) had a high probability of fragmentation in any region. Patients with a high probability of fragmentation had more frequently dilated cardiomyopathy (39.4% vs. 33.0%, p = 0.019), left bundle branch block (40.8% vs. 32.5%, p = 0.006) and a higher use of cardiac resynchronization therapy with defibrillator (CRT-D) devices (33.9% vs. 26.3%, p = 0.004). After adjustment in a multivariable Cox model, there was no significant association between the probability of global or regional fQRS and appropriate ICD therapy, inappropriate shock and short- or long-term mortality.ConclusionThere was no association between the automatically quantified probability of the presence of fQRS and outcome. This lack of predictive value might be due to the algorithm used, which identifies only the presence but not the severity of fragmentation.

BackgroundDexmedetomidine (DEX) and propofol are popular anesthetics, but it remains unknown whether DEX reduces the incidence of arrhythmias compared with propofol after cardiac surgery.MethodsWe performed a comprehensive search for RCTs (Randomized Controlled Trials) that compared the incidence of arrhythmias between DEX and propofol in adults who had undergone cardiac surgery across three databases (PubMed, Embase, the Cochrane Library), and ClinicalTrials.gov up to October 3, 2023. The primary outcome was ventricular arrhythmias, the secondary outcomes were bradycardia and atrial fibrillation (AF).ResultsOur analysis included 7 RCTs with 1,004 patients (mean age: 64.37, male: 71.11%) undergoing cardiac surgery, and the incidence of in-hospital arrhythmia was 22.01% (ventricular arrhythmias 2.75%, bradycardia 3.33%, AF 18.63%). Perioperative or postoperative use of DEX reduced the incidence of in-hospital ventricular arrhythmias [Odds Ratio (OR) 0.14, 95% Confidence Interval (CI) 0.03–0.66], but increased the risk of in-hospital bradycardia (OR 2.88, 95% CI 1.02–8.17) compared with propofol. The trial sequence analysis verified the adequacy of sample size and robustness of the ventricular arrhythmias and bradycardia. There was no significant reduced incidence of the use of DEX in the incidence of AF (OR 0.69, 95% CI 0.36–1.29). The GRADE assessment indicated a high certainty for ventricular arrhythmias and bradycardia and a moderate certainty for AF.ConclusionsOur findings suggested the use of DEX reduces in-hospital ventricular arrhythmias but increases bradycardia incidence compared to propofol in adult patients undergoing cardiac surgery. Further studies are needed to assess the impact of dexmedetomidine on atrial fibrillation compared to propofol.Systematic Review Registrationhttp://www.crd.york.ac.uk/prospero/ PROSPERO, identifier (CRD42023482193).

Abstract Background The incidence of myocardial infarction (MI) and sudden cardiac death (SCD) is significantly higher in individuals with Type 2 Diabetes Mellitus (T2DM) than in the general population. Strategies for the prevention of fatal arrhythmias are often insufficient, highlighting the need for additional non-invasive diagnostic tools. The T-wave heterogeneity (TWH) index measures variations in ventricular repolarization and has emerged as a promising predictor for severe ventricular arrhythmias. Although the EMPA-REG trial reported reduced cardiovascular mortality with empagliflozin, the underlying mechanisms remain unclear. This study investigates the potential of empagliflozin in mitigating cardiac electrical instability in patients with T2DM and coronary heart disease (CHD) by examining changes in TWH. Methods Participants were adult outpatients with T2DM and CHD who exhibited TWH > 80 µV at baseline. They received a 25 mg daily dose of empagliflozin and were evaluated clinically including electrocardiogram (ECG) measurements at baseline and after 4 weeks. TWH was computed from leads V4, V5, and V6 using a validated technique. The primary study outcome was a significant (p

Abstract Background Ubiquitin-specific protease 38 (USP38), belonging to the USP family, is recognized for its role in controlling protein degradation and diverse biological processes. Ventricular arrhythmias (VAs) following heart failure (HF) are closely linked to ventricular electrical remodeling, yet the specific mechanisms underlying VAs in HF remain inadequately explored. In this study, we examined the impact of USP38 on VAs in pressure overload-induced HF. Methods Cardiac-specific USP38 knockout mice, cardiac-specific USP38 transgenic mice and their matched control littermates developed HF induced by aortic banding (AB) surgery. After subjecting the mice to AB surgery for a duration of four weeks, comprehensive investigations were conducted, including pathological analysis and electrophysiological assessments, along with molecular analyses. Results We observed increased USP38 expression in the left ventricle of mice with HF. Electrocardiogram showed that the USP38 knockout shortened the QRS interval and QTc, while USP38 overexpression prolonged these parameters. USP38 knockout decreased the susceptibility of VAs by shortening action potential duration (APD) and prolonging effective refractory period (ERP). In addition, USP38 knockout increased ion channel and Cx43 expression in ventricle. On the contrary, the increased susceptibility of VAs and the decreased expression of ventricular ion channels and Cx43 were observed with USP38 overexpression. In both in vivo and in vitro experiments, USP38 knockout inhibited TBK1/AKT/CAMKII signaling, whereas USP38 overexpression activated this pathway. Conclusion Our data indicates that USP38 increases susceptibility to VAs after HF through TBK1/AKT/CAMKII signaling pathway, Consequently, USP38 may emerge as a promising therapeutic target for managing VAs following HF.

Abstract Background Implantable cardioverter‐defibrillator (ICD) offers an opportunity to study inducibility of ventricular tachycardia (VT) or ventricular fibrillation (VF) by performing noninvasive programmed ventricular stimulation (NIPS). Whether NIPS can predict future arrhythmic events or mortality in patients with primary prevention ICD, has not yet been examined. Methods From the NIPS‐ICD study (ClinicalTrials ID: NCT02373306) 41 consecutive patients (34 males, age 64 ± 11 years, 76% ischemic cardiomyopathy [ICM]) had ICD for primary prevention indication. Patients underwent NIPS using a standardized protocol of up to three premature extrastimuli at 600, 500 and 400 ms drive cycle lengths. NIPS was classified as positive if sustained VT or VF was induced. The study endpoint was occurrence of sustained VT/VF during the follow‐up. Results At baseline NIPS, VT/VF was induced in 8 (20%) ICM patients. During the 5‐year follow‐up, the VT/VF occurred in 7 (17%) patients, all with ICM. The difference between NIPS‐inducible versus NIPS‐noninducible patients regarding VT/VF occurrence did not meet statistical significance (38% vs. 12%, log rank test p = .11). After a 5‐year follow‐up, the mortality rate was significantly higher in patients who had VT/VF induced at NIPS versus no VT/VF at NIPS (38% vs. 12%, p = .043). The occurrence of a composite endpoint consisting of VT/VF recurrence or death in patients with ICM was also most frequent in the NIPS‐inducible group (75% vs. 35%, p = .037). Conclusions Inducibility of VT/VF during NIPS in ICM patients with primary prevention ICD is associated with higher mortality and higher incidence of composite endpoint consisting of death or VT/VF during a long‐term observation.

Non-syndromic mitral valve prolapse (MVP) is a common disease. In most cases, its benign course is noted, however, a connection between MVP and ventricular arrhythmias is reported, as well as sudden cardiac death. Clinical signs (chest pain, syncope/lipotymia, mid-systolic click), results of instrumental studies (electrocardiographic, echocardiographic, magnetic resonance imaging) allow us to identify known ("old") risk factors and new phenomena encountered in rhythm and conduction disturbances during MVP. Signs of "arrhythmic" MVP, often detected in young women, include prolapse of thickened both mitral valve leaflets, T wave inversion in the inferior basal leads on the electrocardiogram, annulus fibrosus disjunction, fibrosis of the papillary muscles and myocardium in the inferior basal wall of the left ventricle, determined by magnetic resonance imaging. resonance tomography and myocardial biopsies. In 2022, the European Heart Rhythm Association Expert Consensus presented risk stratification and treatment principles for patients with arrhythmic MVP, identifying low, intermediate and high-risk groups, and in 2024, the first meta-analysis of studies was performed to identify prognostic risk factors of arrhythmic MVP. The most significant predictors of arrhythmias included late gadolinium enhancement on magnetic resonance imaging, T-wave inversion on the electrocardiogram, prolapse of both mitral valve leaflets, and mitral annulus disjunction. When choosing treatment for patients with arrhythmic MVP, clinical characteristics are taken into account and a personalized approach is used to prevent sudden cardiac death and severe ventricular arrhythmias. As a rule, to prevent sudden cardiac death in patients with arrhythmic MVP, four treatment options are considered: medications (beta-blockers or non-dihydropyridine slow calcium channel blockers, a combination of a beta-blocker and flecainide, or amiodarone), radiofrequency ablation, surgical treatment of the mitral valve, implantable cardioverter — defibrillator (for primary or secondary prevention of sudden cardiac death).The rationale for surgical, electrophysiological, and/or therapeutic treatments depends on the specific rhythm disorder.