Pulsed field ablation: A promising approach for ventricular tachycardia ablation

Radiofrequency ablation (RFA) has been a central therapeutic strategy for ventricular tachycardia (VT). However, concerns about its long-term effectiveness and complications have arisen. Pulsed field ablation (PFA), characterized by its nonthermal, highly tissue-selective ablation technique, has emerged as a promising alternative. This comprehensive review delves into the potential advantages and opportunities presented by PFA in the realm of VT, drawing insights from both animal experimentation and clinical case studies. PFA shows promise in generating superior lesions within scarred myocardial tissue, and its inherent repetition dependency holds the potential to enhance therapeutic outcomes. Clinical cases underscore the promise of PFA for VT ablation. Despite its promising applications, challenges such as catheter maneuverability and proarrhythmic effects require further investigation. Large-scale, long-term studies are essential to establish the suitability of PFA for VT treatment.

Predictive value of the PRAETORIAN score for defibrillation test success in patients with subcutaneous ICD: A subanalysis of the PRAETORIAN-DFT trial

BACKGROUND

The PRAETORIAN score estimates the risk of failure of subcutaneous implantable cardioverter-defibrillator (S-ICD) therapy by using generator and lead positioning on bidirectional chest radiographs. The PRospective randomized compArative trial of subcutanEous implanTable cardiOverter-defibrillatoR ImplANtation with and without DeFibrillation Testing (PRAETORIAN-DFT) investigates whether PRAETORIAN score calculation is noninferior to defibrillation testing (DFT) with regard to first shock efficacy in spontaneous events.

OBJECTIVE

This prespecified subanalysis assessed the predictive value of the PRAETORIAN score for defibrillation success in induced ventricular arrhythmias.

METHODS

This multicenter investigator-initiated trial randomized 965 patients between DFT and PRAETORIAN score calculation after de novo S-ICD implantation. Successful DFT was defined as conversion of induced ventricular arrhythmia in <5 seconds from shock delivery within 2 attempts. Bidirectional chest radiographs were obtained after implantation. The predictive value of the PRAETORIAN score for DFT success was calculated for patients in the DFT arm.

RESULTS

In total, 482 patients were randomized to undergo DFT. Of these patients, 457 (95%) underwent DFT according to protocol, of whom 445 (97%) had successful DFT and 12 (3%) had failed DFT. A PRAETORIAN score of ≥90 had a positive predictive value of 25% for failed DFT, and a PRAETORIAN score of <90 had a negative predictive value of 99% for successful DFT. A PRAETORIAN score of ≥90 was the strongest independent predictor for failed DFT (odds ratio 33.77; confidence interval 6.13-279.95; P < .001).

CONCLUSION

A PRAETORIAN score of <90 serves as a reliable indicator for DFT success in patients with S-ICD, and a PRAETORIAN score of ≥90 is a strong predictor for DFT failure.

Catheter ablation versus antiarrhythmic drug therapy for sustained ventricular tachycardia in patients with hypertrophic cardiomyopathy

BACKGROUND

Ventricular tachycardia (VT) is the primary cause of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, the strategy for VT treatment in HCM patients remains unclear. This study is aimed to compare the effectiveness of catheter ablation versus antiarrhythmic drug (AAD) therapy for sustained VT in patients with HCM.

METHODS

A total of 28 HCM patients with sustained VT at 4 different centers between December 2012 and December 2021 were enrolled. Twelve underwent catheter ablation (ablation group) and sixteen received AAD therapy (AAD group). The primary outcome was VT recurrence during follow-up.

RESULTS

Baseline characteristics were comparable between two groups. After a mean follow-up of 31.4 ± 17.5 months, the primary outcome occurred in 35.7% of the ablation group and 90.6% of the AAD group (hazard ratio [HR], 0.29 [95%CI, 0.10-0.89]; P = 0.021). No differences in hospital admission due to cardiovascular cause (25.0% vs. 71.0%; P = 0.138) and cardiovascular cause-related mortality/heart transplantation (9.1% vs. 50.6%; P = 0.551) were observed. However, there was a significant reduction in the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation in ablation group as compared to that of AAD group (42.9% vs. 93.7%; HR, 0.34 [95% CI, 0.12-0.95]; P = 0.029).

CONCLUSIONS

In HCM patients with sustained VT, catheter ablation reduced the VT recurrence, and the composite endpoint of VT recurrence, hospital admission due to cardiovascular cause, cardiovascular cause-related mortality, or heart transplantation as compared to AAD.

Bleeding and Thrombosis in Patients With Out-of-Hospital Ventricular Tachycardia/Ventricular Fibrillation Arrest Treated With Extracorporeal Cardiopulmonary Resuscitation

BACKGROUND

Extracorporeal cardiopulmonary resuscitation improves outcomes after out-of-hospital cardiac arrest. However, bleeding and thrombosis are common complications. We aimed to describe the incidence and predictors of bleeding and thrombosis and their association with in-hospital mortality.

METHODS AND RESULTS

Consecutive patients presenting with refractory ventricular tachycardia/ventricular fibrillation out-of-hospital cardiac arrest between December 2015 and March 2022 who met the criteria for extracorporeal cardiopulmonary resuscitation initiation at our center were included. Major bleeding was defined by the Extracorporeal Life Support Organization's criteria. Adjusted analyses were done to seek out risk factors for bleeding and thrombosis and evaluate their association with mortality. Major bleeding occurred in 135 of 200 patients (67.5%), with traumatic bleeding from cardiopulmonary resuscitation in 73 (36.5%). Baseline demographics and arrest characteristics were similar between groups. In multivariable analysis, decreasing levels of fibrinogen were independently associated with bleeding (adjusted hazard ratio [aHR], 0.98 per every 10 mg/dL rise [95% CI, 0.96-0.99]). Patients who died had a higher rate of bleeds per day (0.21 versus 0.03, P<0.001) though bleeding was not significantly associated with in-hospital death (aHR, 0.81 [95% CI. 0.55-1.19]). A thrombotic event occurred in 23.5% (47/200) of patients. Venous thromboembolism occurred in 11% (22/200) and arterial thrombi in 15.5% (31/200). Clinical characteristics were comparable between groups. In adjusted analyses, no risk factors for thrombosis were identified. Thrombosis was not associated with in-hospital death (aHR, 0.65 [95% CI, 0.42-1.03]).

CONCLUSIONS

Bleeding is a frequent complication of extracorporeal cardiopulmonary resuscitation that is associated with decreased fibrinogen levels on admission whereas thrombosis is less common. Neither bleeding nor thrombosis was significantly associated with in-hospital mortality.

Takotsubo cardiomyopathy following pacemaker insertion complicated with polymorphic ventricular tachycardia: a case report

BACKGROUND

Takotsubo cardiomyopathy is a novel form of rapidly reversible heart failure occurring secondary to a stressor that mimics an acute coronary event. The underlying etiology of the stressor is highly variable and can include medical procedures. Pacemaker insertion is an infrequent cause of Takotsubo cardiomyopathy.

CASE PRESENTATION

An 86-year-old Caucasian woman underwent an uncomplicated pacemaker insertion for symptomatic complete heart block in the background of slow atrial fibrillation. A transient episode of polymorphic ventricular tachycardia was noted on day 1 following the procedure; however, her pacemaker was checked and, as she remained stable, she was discharged home. She presented again 5 days later with symptomatic heart failure. Chest X-ray confirmed pulmonary edema. Echocardiography confirmed new onset severe left ventricle dysfunction. Pacemaker checks were normal and lead placement was confirmed. Though her troponin I was elevated, her coronary angiogram was normal. Contrast enhanced echocardiography suggested apical ballooning favoring Takotsubo cardiomyopathy. She was treated for heart failure and made a good recovery. Her follow-up echocardiography a month later showed significant improvement in left ventricle function.

CONCLUSIONS

Takotsubo cardiomyopathy is mediated by a neuro-cardiogenic mechanism due to hypothalamic-pituitary-adrenal axis activation. It generally has a good prognosis. Complications though uncommon, can occur and include arrhythmias. Pacemaker insertion as a precipitant stressor is an infrequent cause of Takotsubo cardiomyopathy. As pacemaker insertions are more frequent in the elderly age group, this phenomenon should be recognized as a potential complication.

Impact of preventive substrate catheter ablation on implantable cardioverter-defibrillator interventions in patients with ischaemic cardiomyopathy and infarct-related coronary chronic total occlusion

AIMS

Primary prevention patients with ischaemic cardiomyopathy and chronic total occlusion of an infarct-related coronary artery (CTO) are at a particularly high risk of implantable cardioverter-defibrillator (ICD) therapy occurrence. The trial was designed to evaluate the efficacy of preventive CTO-related substrate ablation strategy in ischaemic cardiomyopathy patients undergoing primary prevention ICD implantation.

METHODS AND RESULTS

The PREVENTIVE VT study was a prospective, multicentre, randomized trial including ischaemic patients with ejection fraction ≤40%, no documented ventricular arrhythmias (VAs), and evidence of scar related to the coronary CTO. Patients were randomly assigned 1:1 to a preventive substrate ablation before ICD implantation or standard therapy with ICD implantation only. The primary outcome was a composite of appropriate ICD therapy or unplanned hospitalization for VAs. Secondary outcomes included the primary outcome's components, the incidence of appropriate ICD therapies, cardiac hospitalization, electrical storm, and cardiovascular (CV) mortality. Sixty patients were included in the study. During the mean follow-up of 44.7 ± 20.7 months, the primary outcome occurred in 5 (16.7%) patients undergoing preventive substrate ablation and in 13 (43.3%) patients receiving only ICD [hazard ratio (HR): 0.33; 95% confidence interval (CI): 0.12-0.94; P = 0.037]. Patients in the preventive ablation group also had fewer appropriate ICD therapies (P = 0.039) and the electrical storms (Log-rank: P = 0.01). While preventive ablation also reduced cardiac hospitalizations (P = 0.006), it had no significant impact on CV mortality (P = 0.151).

CONCLUSION

Preventive ablation of the coronary CTO-related substrate in patients undergoing primary ICD implantation is associated with the reduced risk of appropriate ICD therapy or unplanned hospitalization due to VAs.

Neuroimmune modulation mediated by IL-6: A potential target for the treatment of ischemia-induced ventricular arrhythmias

BACKGROUND

Neural remodeling in the left stellate ganglion (LSG), as mediated by neuroimmune reactions, promotes cardiac sympathetic nerve activity (SNA) and thus increases the incidence of ventricular arrhythmias (VAs). Interleukin-6 (IL-6) is an important factor of the neuroimmune interaction.

OBJECTIVE

The present study explored the effects of IL-6 on LSG hyperactivity and the incidence of VAs.

METHODS

Eighteen beagles were randomly allocated to a control group (saline with myocardial infarction [MI], n  =  6), adeno-associated virus (AAV) group (AAV with MI, n  =  6), and IL-6 group (overexpression of IL-6 via AAV vector with MI, n  =  6). Ambulatory electrocardiography was performed before and 30 days after AAV microinjection into the LSG. LSG function and ventricular electrophysiology were assessed at 31 days after surgery, and a canine MI model was established. Samples of the LSG were collected for immunofluorescence staining and molecular biological evaluation. Blood samples and 24-hour Holter data were obtained from 24 patients with acute MI on the day after they underwent percutaneous coronary intervention to assess the correlation between IL-6 levels and SNA.

RESULTS

IL-6 overexpression increased cardiac SNA and worsened postinfarction VAs. Furthermore, sustained IL-6 overexpression enhanced LSG function, promoted expression of nerve growth factor, c-fos, and fos B in the LSG, and activated the signal transducer and activator of transcription 3/regulator of G protein signalling 4 signaling pathway. Clinical sample analysis revealed a correlation between serum IL-6 levels and heart rate variability frequency domain index as well as T-wave alternans.

CONCLUSION

IL-6 levels are correlated with cardiac SNA. Chronic overexpression of IL-6 mediates LSG neural remodeling through the signal transducer and activator of transcription 3/regulator of G protein signalling 4 signaling pathway, elevating the risk of VA after MI.

The Beneficial Role of Telemedicine for Arrhythmic Risk Stratification in Asymptomatic Brugada Syndrome: An Exemplary Case Report

Telemedicine and remote monitoring devices, including implantable loop recorders (ILR), are increasingly adopted in the cardiologic setting. These are valuable tools in the arrhythmic stratification of patients at risk of sudden cardiac death, providing a tailored therapeutic management to prevent lethal arrhythmias. We report a case of an asymptomatic 18-year-old boy with a family history of syncope and cardiac arrest, who had a diagnosis of Brugada syndrome with an inducible type 1 pattern and carrier of a missense mutation of the SCN5A gene. In light of the risk factors, although not recommended by current guidelines, we decided to proceed with the implantation of an ILR with remote monitoring service. A few months later, an episode of asymptomatic sustained polymorphic ventricular tachycardia was promptly observed by the remote monitoring, leading to a timely implantation of a subcutaneous cardiac implantable defibrillator.

Ventricular Arrhythmias After Primary Percutaneous Coronary Intervention for STEMI

Importance

Currently, mortality risk for patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) with an uncomplicated postprocedure course is low. Less is known regarding the risk of in-hospital ventricular tachycardia (VT) and ventricular fibrillation (VF).

Objective

To evaluate the risk of late VT and VF after primary PCI for STEMI.

Design, Setting, and Participants

This cohort study included adults aged 18 years or older with STEMI treated with primary PCI between January 1, 2015, and December 31, 2018, identified in the US National Cardiovascular Data Registry Chest Pain-MI Registry. Data were analyzed from April to December 2020.

Main Outcomes and Measures

Multivariable logistic regression was used to evaluate the risk of late VT (≥7 beat run of VT during STEMI hospitalization ≥1 day after PCI) or VF (any episode of VF≥1 day after PCI) associated with cardiac arrest and associations between late VT or VF and in-hospital mortality in the overall cohort and a cohort with uncomplicated STEMI without prior myocardial infarction or heart failure, systolic blood pressure less than 90 mm Hg, cardiogenic shock, cardiac arrest, reinfarction, or left ventricular ejection fraction (LVEF) less than 40%.

Results

A total of 174 126 eligible patients with STEMI were treated with primary PCI at 814 sites in the study; 15 460 (8.9%) had VT or VF after primary PCI, and 4156 (2.4%) had late VT or VF. Among the eligible patients, 99 905 (57.4%) at 807 sites had uncomplicated STEMI. The median age for patients with late VT or VF overall was 63 years (IQR, 55-73 years), and 75.5% were men; the median age for patients with late VT or VF with uncomplicated STEMI was 60 years (IQR, 53-69 years), and 77.7% were men. The median length of stay was 3 days (IQR, 2-7 days) for the overall cohort with late VT or VF and 3 days (IQR, 2-4 days) for the cohort with uncomplicated STEMI with late VT or VF. The risk of late VT or VF was 2.4% (overall) and 1.7% (uncomplicated STEMI). Late VT or VF with cardiac arrest occurred in 674 patients overall (0.4%) and in 117 with uncomplicated STEMI (0.1%). LVEF was the most significant factor associated with late VT or VF with cardiac arrest (adjusted odds ratio [AOR] for every 5-unit decrease ≤40%: 1.67; 95% CI, 1.54-1.85). Late VT or VF events were associated with increased odds of in-hospital mortality in the overall cohort (AOR, 6.40; 95% CI, 5.63-7.29) and the cohort with uncomplicated STEMI (AOR, 8.74; 95% CI, 6.53-11.70).

Conclusions and Relevance

In this study, a small proportion of patients with STEMI treated with primary PCI had late VT or VF. However, late VT or VF with cardiac arrest was rare, particularly in the cohort with uncomplicated STEMI. This information may be useful when determining the optimal timing for hospital discharge after STEMI.

Association between survival and number of shocks for pulseless ventricular arrhythmias during pediatric in-hospital cardiac arrest in a national registry

BACKGROUND

Annually 15,200 children suffer an in-hospital cardiac arrest (IHCA) in the US. Ventricular fibrillation or pulseless ventricular tachycardia (VF/pVT) is the initial rhythm in 10-15% of these arrests. We sought to evaluate the association of number of shocks and early dose escalation with survival for initial VF/pVT in pediatric IHCA.

METHODS

Using 2000-2020 data from the American Heart Association's (AHA) Get with the Guidelines®-Resuscitation (GWTG-R) registry, we identified children >48 hours of life and ≤18 years who had an IHCA from initial VF/pVT and received defibrillation.

RESULTS

There were 251 subjects (37.7%) who received a single shock and 415 subjects (62.3%) who received multiple shocks. Baseline and cardiac arrest characteristics did not differ between those who received a single shock versus multiple shocks except for duration of arrest and calendar year. The median first shock dose was consistent with AHA dosing recommendations and not different between those who received a single shock versus multiple shocks. Survival was improved for those who received a single shock compared to multiple shocks. However, no difference in survival was noted between those who received 2, 3, or ≥4 shocks. Of those receiving multiple shocks, no difference was observed with early dose escalation.

CONCLUSIONS

In pediatric IHCA, most patients with initial VF/pVT require more than one shock. No distinctions in patient or pre-arrest characteristics were identified between those who received a single shock versus multiple shocks. Subjects who received a single shock were more likely to survive to hospital discharge even after adjusting for duration of resuscitation.

Ventricular Tachycardia Ablation Endpoints: Moving Beyond Noninducibility

In patients with structural heart disease and ventricular tachycardia (VT) undergoing catheter ablation, the response to programmed electrical stimulation (PES) at the end of the procedure has been traditionally used to evaluate the acute success and predict long-term outcomes. Although noninducibility at PES has been extensively investigated and validated in clinical trials and large multicenter registries, its performance in predicting long-term freedom from VT is suboptimal. In addition, PES has inherent limitations related to the influence of background antiarrhythmic drug therapy, periprocedural use of anesthesia, and the heterogeneity in PES protocols. The increased utilization of substrate-based ablation approaches that focus on ablation of abnormal electrograms identified with mapping in sinus or paced rhythm has been paralleled by a need for additional procedural endpoints beyond VT noninducibility at PES. This article critically appraises the relative merits and limitations of different procedural endpoints according to different ablation techniques for catheter ablation of scar-related VT.

Predictors of 30-day survival after emergent percutaneous coronary intervention following ventricular tachyarrhythmias complicating acute myocardial infarction

BACKGROUND

Little has been reported on the predictors of 30-day survival after emergent percutaneous coronary intervention (PCI) following life-threatening ventricular tachyarrhythmias associated with acute myocardial infarction (AMI).

METHODS

We analyzed 55 consecutive patients who underwent an emergent PCI after ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT) complicating AMI between September 2014 and March 2023 in our hospital. These patients were categorized into two groups: survival group (S group) who survived >30 days after the emergent PCI and death group (D group) who died by 30 days after the emergent PCI. We compared the patient characteristics, coronary angiographic findings, and PCI procedures between the two groups.

RESULTS

S group consisted of 40 patients. In the univariate analysis, absence of diabetes mellitus, presence of immediate cardiopulmonary resuscitation (CPR), low arterial lactate, and single-vessel coronary artery disease (CAD) were associated with 30-day survival after the emergent PCI (P = 0.048, P < 0.001, P = 0.009, and P = 0.003, respectively). In the multivariate analysis, presence of immediate CPR and single-vessel CAD were independently associated with 30-day survival after the emergent PCI (P = 0.023 and P = 0.032, respectively).

CONCLUSIONS

Immediate CPR and single-vessel CAD were significant predictors of 30-day survival after the emergent PCI following VF or pulseless VT complicating AMI. Absence of diabetes mellitus and low arterial lactate were associated with 30-day survival in the univariate analysis.

Safety and Efficacy of Ultrasound-Guided Sympathetic Blockade by Proximal Intercostal Block in Electrical Storm Patients

BACKGROUND

Electrical storm (ES) patients who fail standard therapies have a high mortality rate. Previous studies report effective management of ES with bedside, ultrasound-guided percutaneous stellate ganglion block (SGB). We report our experience with sympathetic blockade administered via a novel alternative approach: proximal intercostal block (PICB). Compared with SGB, this technique targets an area typically free of other catheters and support devices, and may pose less strict requirements for anticoagulation interruption, along with lower risk of focal neurological side effects.

OBJECTIVES

The authors sought to describe the safety and efficacy of PICB in patients with refractory ES.

METHODS

We reviewed our institutional data on ES patients who underwent PICB between January 2018 and February 2023 to analyze procedural safety and short- and long-term outcomes.

RESULTS

A total of 15 consecutive patients with ES underwent PICB during this period. Of those, 11 patients (73.3%) were maintained on PICB alone, and 4 patients (26.6%) were maintained on combined block with SGB and PICB. Overall, 72.7% patients who were maintained on PICB alone and 77.8% patients who were maintained on bilateral PICB had excellent arrhythmia suppression. After PICB, implantable cardioverter-defibrillator therapies were significantly reduced (P < 0.05), with 93.3% of patients receiving PICB having no implantable cardioverter-defibrillator shock until discharge or heart transplant. Anticoagulation was continued in all patients and there were no procedure-related complications. Apart from mild transient neurological symptoms seen in 3 patients, no significant neurological or hemodynamic sequelae were observed.

CONCLUSIONS

In patients with refractory ES, continuous PICB provided safe and effective sympathetic block (77.8% ventricular arrhythmia suppression), achievable without interruption of anticoagulation, and without significant side effects.

Comparison of novel intrinsic versus conventional antitachycardia pacing for ventricular tachycardia among implantable cardioverter-defibrillator recipients

INTRODUCTION

Intrinsic antitachycardia pacing (iATP) is a novel automated antitachycardia pacing (ATP) that provides individual treatment to terminate ventricular tachycardia (VT). However, the clinical efficacy of iATP in comparison with conventional ATP is unknown. We aim to compare the termination rate of VT between iATP and conventional ATP in patients with implantable cardioverter-defibrillators using a unique setting of different sequential orders of both ATP algorisms.

METHODS

Patients with the iATP algorithm were assigned to iATP-first and conventional ATP-first groups sequentially. In the iATP-first group, a maximum of seven iATP sequences were delivered, followed by conventional burst and ramp pacing. In contrast, in the conventional ATP-first group, two bursts and ramp pacing were initially programmed, followed by iATP sequences. We compared the success rates of VT termination in the first and secondary programmed ATP zones between the two groups.

RESULTS

Fifty-eight and 56 patients were enrolled in the iATP-first and conventional ATP-first groups, and 67 and 44 VTs were analyzed in each group, respectively. At the first single ATP therapy, success rates were 64% and 70% in the iATP and conventional groups, respectively. At the end of the first iATP treatment zone, the success rate increased from 64% to 85%. Moreover, secondary iATP therapy following the failure of conventional ATPs increased the success rate from 80% to 93%. There was a significant benefit of alternative iATP for VT termination compared to secondary conventional ATP (100% vs. 33%, p = .028).

CONCLUSIONS

iATP may be beneficial as a secondary therapy after failure of conventional ATP to terminate VT.

A Multicenter Study of Stellate Ganglion Block as a Temporizing Treatment for Refractory Ventricular Arrhythmias

BACKGROUND

Ventricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry.

OBJECTIVES

This study examined the efficacy of SGB for treatment/temporization of refractory VT/VF.

METHODS

The authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB.

RESULTS

In total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001).

CONCLUSIONS

In the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy.

A rare case of upper septal fascicular ventricular tachycardia presented in a case report

CASE SUMMARY

A 71-year-old presented at the outpatient clinic with palpitations and NYHA II functional class. 12-lead ECG exhibited Upper septal idiopathic left ventricular tachycardia (US-ILVT). Ventricular tachycardia (VT) was interrupted with Verapamil administration, no further recurrences were documented after beta-blockers therapy was started. No coronary artery stenosis were detected. The US-ILVT was successfully treated by ablating the proximal site of the left anterior fascicle (LAF), where diastolic potential (P1) and pre-systolic potential (P2) with inverted sequence were detected during the electrophysiology study (EP) study. Cardiac magnetic resonance imaging (CMR) was performed with demonstration of intramyocardial late gadolinium enhancement (LGE) at the level of middle-basal portions of interventricular septum and basal portion of infero-lateral wall and no edema detection. A single catheter implantable cardioverter defibrillator (ICD) was implanted as secondary prevention. VT has never recurred during 3 months of follow-up with remote control of ICD.

DISCUSSION

To the best of our knowledge, this is the first report in which US-ILVT was associated with ventricular septal LGE, suggestive of previous myocarditis, as substrate of re-entrant circuit. Scar-related ventricular tachycardia circuit is also suggested by the evidence of a premature ventricular complex (PVC) as trigger of recurrent VT in our case.

Evaluation of patients with implantable cardioverter-defibrillator in a Latin American tertiary center

INTRODUCTION

Despite advancements in implantable cardioverter-defibrillator (ICD) technology, sudden cardiac death (SCD) remains a persistent public health concern. Chagas disease (ChD), prevalent in Brazil, is associated with increased ventricular tachycardia (VT) and ventricular fibrillation (VF) events and SCD compared to other cardiomyopathies.

METHODS

This retrospective observational study included patients who received ICDs between October 2007 and December 2018. The study aims to assess whether mortality and VT/VF events decreased in patients who received ICDs during different time periods (2007-2010, 2011-2014, and 2015-2018). Additionally, it seeks to compare the prognosis of ChD patients with non-ChD patients. Time periods were chosen based on the establishment of the Arrhythmia Service in 2011. The primary outcome was overall mortality, assessed across the entire sample and the three periods. Secondary outcomes included VT/VF events and the combined outcome of death or VT/VF.

RESULTS

Of the 885 patients included, 31% had ChD. Among them, 28% died, 14% had VT/VF events, and 37% experienced death and/or VT/VF. Analysis revealed that period 3 (2015-2018) was associated with better death-free survival (p = .007). ChD was the only variable associated with a higher rate of VT/VF events (p < .001) and the combined outcome (p = .009).

CONCLUSION

Mortality and combined outcome rates decreased gradually for ICD patients during the periods 2011-2014 and 2015-2018 compared to the initial period (2007-2010). ChD was associated with higher VT/VF events in ICD patients, only in the first two periods.

[Rhythm management in patients with heart failure]

INTRODUCTION

Arrhythmias manifest frequently in individuals with heart failure, posing a notable threat of mortality and morbidity. While the prevention of sudden cardiac death through ICD therapy remains pivotal, accurate risk stratification remains a challenging task even in 2024. Recent data underscore the early consideration of catheter ablation for ventricular tachycardias. Although antiarrhythmic drug therapy serves as an ancillary measure for symptomatic patients, it does not confer prognostic advantages. The holistic management of arrhythmias in heart failure necessitates a systematic, multidimensional approach that initiates with evidence-based medical therapy for heart failure and integrates device-based and interventional therapies. Noteworthy clinical studies have illustrated the positive prognostic impact of early rhythm control strategies, particularly catheter ablation, in individuals managing heart failure and atrial fibrillation.

Management of patients with an electrical storm or clustered ventricular arrhythmias: a clinical consensus statement of the European Heart Rhythm Association of the ESC-endorsed by the Asia-Pacific Heart Rhythm Society, Heart Rhythm Society, and Latin-American Heart Rhythm Society

Electrical storm (ES) is a state of electrical instability, manifesting as recurrent ventricular arrhythmias (VAs) over a short period of time (three or more episodes of sustained VA within 24 h, separated by at least 5 min, requiring termination by an intervention). The clinical presentation can vary, but ES is usually a cardiac emergency. Electrical storm mainly affects patients with structural or primary electrical heart disease, often with an implantable cardioverter-defibrillator (ICD). Management of ES requires a multi-faceted approach and the involvement of multi-disciplinary teams, but despite advanced treatment and often invasive procedures, it is associated with high morbidity and mortality. With an ageing population, longer survival of heart failure patients, and an increasing number of patients with ICD, the incidence of ES is expected to increase. This European Heart Rhythm Association clinical consensus statement focuses on pathophysiology, clinical presentation, diagnostic evaluation, and acute and long-term management of patients presenting with ES or clustered VA.

Acute myocardial infarction revealed by recurrent ventricular tachyarrhythmias detected by remote monitoring

Remote monitoring (RM) of cardiac implantable electronic devices (CIED) represented a major improvement in clinical practice and has been used with multiple indications. Many parameters monitored on a daily basis by current CIED can indeed assist in clinical practice (eg, decompensated heart failure) by providing the patient with optimal timing for anticipated outpatient visit or urgent medical care. Recognition of acute myocardial infarction (AMI) is not usually considered among the capabilities of RM. We present the case of an AMI occurring without any ischaemic symptoms but associated with recurrent ventricular tachyarrhythmias effectively treated by multiple interventions of the implantable cardioverter defibrillator and promptly detected by RM personnel, who recommended the patient to quickly access to the emergency department where diagnosis and revascularization of an otherwise untreated myocardial infarction was performed.