2017 AHA/ACC/HRS Guideline for Management of Patients With Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death: Executive Summary: A Report of the American College of Cardiology/American Heart Association Task Force on Clinical Practice Guidelines and the Heart Rhythm Society

Performance and Safety of the Extravascular Implantable Cardioverter Defibrillator Through Long-Term Follow-Up: Final Results From the Pivotal Study

BACKGROUND

Substernal lead placement of the extravascular implantable cardioverter defibrillator (EV ICD) permits both defibrillation at thresholds similar to those seen with transvenous implantable cardioverter defibrillators and effective anti-tachycardia pacing (ATP) while avoiding the vasculature and associated complications. The global Pivotal study has shown the EV ICD system to be safe and effective through 6 months, but long-term experience has yet to be published. Our aim was to report the performance and safety of the EV ICD system throughout the study.

METHODS

The EV ICD Pivotal study was a prospective, global, single-arm, premarket clinical study. Individuals with a Class I or IIa indication for a single-chamber implantable cardioverter defibrillator per guidelines were enrolled. Freedom from major system- or procedure-related complications and appropriate and inappropriate therapy rates were assessed through 3 years with the Kaplan-Meier method. ATP success was calculated from simple proportions.

RESULTS

An implantation was attempted in 316 patients (25.3% female; 53.8±13.1 years of age; 81.6% primary prevention; left ventricular ejection fraction, 38.9±15.4%). Of 299 patients with a successful implantation, 24 experienced 82 spontaneous arrhythmic episodes that were appropriately treated with ATP only (38, 46.3%), shock only (34, 41.5%), or both (10, 12.2%) for a Kaplan-Meier-estimated rate of first any appropriate therapy of 9.2% at 3 years. ATP was successful in 77.1% (37/48) of episodes, and ATP use significantly increased from discharge to last follow-up visit (P<0.0001). Shock therapy was successful in 100% (27/27) of discrete, spontaneous ventricular arrhythmias. The inappropriate shock rates at 1 and 3 years were 9.8% and 17.5%, respectively, with P-wave oversensing the predominant cause. No major intraprocedural complications were reported, and the estimated freedom from system- or procedure-related major complications was 91.9% at 1 year and 89.0% at 3 years. The most common major complications were lead dislodgement (10 events; n=9 patients, 2.8%), postoperative wound or device pocket infection (n=8, 2.5%), and device inappropriate shock delivery (n=4, 1.3%). Twenty-four system revisions were performed as a result of major complications related to the EV ICD system or procedure.

CONCLUSIONS

From implantation to study completion, the EV ICD Pivotal study demonstrated that a single integrated system with an extravascular lead placed in the substernal space maintains high ATP success, effective defibrillation, and a consistent safety profile.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04060680.

Contemporary Insights into LMNA Cardiomyopathy

PURPOSE OF REVIEW

This review aims to explore how a diagnosis of LMNA-related cardiomyopathy (LMNA-CM) informs clinical management, focusing on the prevention and management of its complications, through practical clinical strategies.

RECENT FINDINGS

Longitudinal studies have enhanced our understanding of the natural history of LMNA-CM including its arrhythmic and non-arrhythmic complications. A LMNA specific ventricular arrhythmia risk prediction strategy has been integrated into clinical practice guidelines. Although less robust, observational studies are shaping gene-specific strategies for mitigating other complications including atrioventricular block, atrial fibrillation and cardiomyopathy, while novel therapies have been evaluated in clinical trials. LMNA-CM follows an aggressive yet generally stereotyped course. Early recognition of anticipated complications allows for more effective prevention and management in both symptomatic and asymptomatic patients.

Temporal trends in population characteristics and type of device among primary prevention implantable cardioverter defibrillator recipients: The DAI-PP programme

BACKGROUND

Patient characteristics, technology and clinical practice surrounding primary prevention implantable cardioverter defibrillators have evolved continuously over time.

AIM

To explore the temporal changes in patient characteristics, pharmacological therapy and device types among implantable cardioverter defibrillator recipients implanted for the primary prevention of sudden cardiac death over the last two decades in France.

METHODS

Characteristics of participants and type of device from the retrospective DAI-PP Pilot Study (2002-2012) were compared with those from the ongoing prospective DAI-PP Consortium (2018 onwards).

RESULTS

This study included 9588 participants overall (DAI-PP Pilot Study, n=5539; DAI-PP Consortium, n=4049). Compared with the DAI-PP Pilot Study, the DAI-PP Consortium subjects were older at implantation (62.5 vs 65.2 years; P=0.001) and had a higher proportion of women (15.1% vs 20.6%; P<0.001), a similar proportion of ischaemic heart disease (60.2% vs 60.2%; P=0.98), a higher left ventricular ejection fraction (27±7% vs 30±8%; P<0.001) and more patients with narrow QRS complexes (30.5% vs 46.0%; P<0.001). The proportion of patients treated with heart failure drugs increased significantly (70.1% vs 83.1%; P<0.001), whereas the use of amiodarone became much less frequent (22.7% vs 14.7%; P<0.001). Finally, the proportions of cardiac resynchronization therapy defibrillators (53.8% vs 46.4%; P<0.001) and dual-chamber defibrillators (23.3% vs 17.3%; P<0.001) decreased, whereas subcutaneous implantable cardioverter defibrillators now account for a sizeable proportion of implants (14.6%).

CONCLUSIONS

Over a 20-year period, the primary prevention implantable cardioverter defibrillator population has evolved significantly, with an older age and a higher proportion of women. The type of device has changed, with fewer cardiac resynchronization therapy defibrillators and more subcutaneous implantable cardioverter defibrillators.

Cardioneuroablation in the Management of Vagally Mediated Bradyarrhythmias-A Comprehensive Review of Ongoing Randomized Controlled Trials

Cardioneuroablation is a rapidly developing procedure for the treatment of vagally mediated bradyarrhythmias. However, the lack of multicenter, randomized trials prevents it from being included in bradyarrhythmia treatment guidelines. So far, only one small, randomized study has been published assessing the effectiveness of this method in the treatment of reflex syncope. This is a brief review of ongoing randomized trials evaluating the effectiveness and safety of cardioneuroablation for the treatment of functional bradyarrhythmias.

Age and Clinically Actionable Events in Patients With Implantable Loop Recorders: Analysis of Multicenter Loop Recorder Registry

INTRODUCTION

Little is known about age and clinical intervention after implantable loop recorder (ILR) insertion. This study investigated the association between age and clinical intervention after ILR implantation.

METHODS AND RESULTS

Data were obtained from a multicenter registry of ILR in Korea (2017-2020, n = 795). ILRs were inserted with indications of unexplained syncope, recurrent palpitation, or cryptogenic stroke. The primary outcome was clinically actionable event that was a composite of the newly detected atrial fibrillation (AF), pacemaker or implantable cardioverter defibrillator (ICD) implantation, catheter ablation, and anticoagulation initiation. The mean age was 64.3 years, and the mean follow-up duration was 20.6 months. Clinically actionable events were observed in 322 (40.5%) patients. Compared to younger age (< 50 years), older age (≥ 50 years) showed higher prevalence of newly detected AF (3.7% vs. 15.8%; p = 0.001), pacemaker implantation (11.2% vs. 21.2%; p = 0.022), and initiation of anticoagulation (3.7% vs. 18.6%; p < 0.001). No significant differences were found in ICD implantation (1.9% vs. 1.3%; p = 0.996) or catheter ablation (3.8% vs. 6.0%; p = 0.512). The older age group more frequently experienced clinically actionable events compared to the younger age group (hazard ratio 2.52, 95% confidence interval: 1.86-3.41; p < 0.001). A significant association was found in the increase of age (per 1-year) and the risk of clinically actionable events (adjusted hazard ratio 1.03, 95% confidence interval 1.02-1.04; p < 0.001).

CONCLUSION

Advanced age is a significant risk factor for clinical intervention after ILR insertion. ILR should be considered more actively in older patients requiring prolonged rhythm monitoring.

Sudden Death in Obesity: Mechanisms and Management

In recent decades, the prevalence of obesity has increased significantly, leading to an epidemic at the global level. Obesity is associated with various metabolic alterations and increases the risk of cardiovascular disease. The most devastating manifestation of cardiovascular disease is sudden cardiac death (SCD), leading to substantial years of potential life lost worldwide. Obesity-related SCD is an increasingly important public health problem and warrants a specific investigative focus on improved risk stratification and prevention. In this review, we summarize the current evidence regarding management of SCD in obesity and discuss knowledge gaps as well as future directions in this field.

Catheter Ablation for Ventricular Tachycardia in Patients With Biopsy-Proven Myocarditis

Background

Catheter ablation (CA) is increasingly recognized as an effective treatment for ventricular tachycardia (VT) in myocarditis patients, although current evidence is based on less robust data.

Objectives

The purpose of this study was to confirm CA's efficacy in reducing VT recurrence and to identify arrhythmic risk factors in biopsy-proven myocarditis patients.

Methods

In this dual-center, retrospective study, we included 50 patients with biopsy-proven myocarditis and VT. They were divided into 2 groups: CA (n = 23) and non-CA (n = 27), with the primary endpoint being VT recurrence at 1-year follow-up.

Results

The average age of participants was 40.8 ± 14.9 years; 48% were men. Over a median 371-day follow-up, 28 (56%) experienced VT recurrence, with 8 patients (35%) in the CA group and 20 patients (74%) in the non-CA group. Kaplan-Meier analysis showed that the rate of VT recurrence in the CA group was significantly lower than in the non-CA group (log-rank P = 0.009). However, this difference was not found in patients with acute myocarditis. Multivariable analysis revealed a significant correlation between the acute stage of myocarditis and VT recurrence in both the general cohort (HR: 3.02; 95% CI: 1.11-8.21; P = 0.031) and the subset undergoing CA (HR: 11.4; 95% CI: 1.02-127.5; P = 0.048).

Conclusions

CA is significantly associated with reduced VT recurrence in biopsy-proven myocarditis, albeit this association is not observed in cases of acute myocarditis. The acute stage of myocarditis is independently associated with an increased risk of VT recurrence.

Electrical storm after acute myocardial infarction treated with radiofrequency ablation under the Escort of ICD

The occurrence of ventricular tachycardia (VT) in patients with acute myocardial infarction (AMI) is associated with poor prognosis. Drug therapy and implantable cardioverter-defibrillators (ICDs) are effective methods to prevent sudden death. Radiofrequency (RF) catheter ablation can map the matrix and mechanism of VT, thereby effectively reducing the occurrence of ICD discharge. This paper reports on the case of a middle-aged man who underwent emergency percutaneous coronary intervention for AMI and developed VT and ventricular fibrillation on day 7 after reperfusion. An ICD was implanted. On day 19, he received catheter ablation because of refractory monomorphic ventricular tachycardia and frequent discharge of the ICD. After three months, the patient had not experienced any further ventricular tachycardia attacks. The conclusion is that RF catheter ablation can resolve the ES after myocardial infarction and significantly reduce the occurrence of ICD discharges.

Drowning incidents precipitated by unusual causes (DIPUCs): A narrative review of their diagnoses, evaluation and management

Drowning is a cause of significant morbidity and mortality worldwide. In most circumstances, the proximate cause is attributable to human factors, such as inexperience, fatigue, intoxication, or hazardous water conditions. The phenomenon of drowning incidents precipitated by unusual circumstances (DIPUCs) - either fatal or nonfatal - involving otherwise healthy individuals under generally safe conditions has not been comprehensively addressed in the medical and drowning literature to date. In this review, we discuss etiologies of DIPUCs, diagnostic clues, suggested workup, suggested postmortem testing, and implications for surviving patients and families. Identifying the cause of a drowning incident can be extremely challenging for the initially treating physician, relying perforce on historical context, environmental clues, physical exam, medical history, eyewitness accounts or video recordings. If no clear explanation for a drowning incident emerges despite a thorough investigation, clinicians should consider some of the less common diagnoses we describe in this paper, and, when appropriate, refer for an autopsy with postmortem molecular genetic testing. While time-consuming, these efforts can prove life-saving for some non-fatal drowning victims and the families of all victims of DIPUCs.

Apical or Septal Right Ventricular Location in Patients Receiving Defibrillation Leads: A Systematic Review and Meta-Analysis

This study reviews the published data comparing the efficacy and safety of apical and septal right ventricle defibrillator lead positioning at 1-year follow-up. Systemic research on Medline (PubMed), ClinicalTrials.gov , and Embase was performed using the keywords "septal defibrillation," "apical defibrillation," "site defibrillation," and "defibrillation lead placement," including implantable cardioverter-defibrillator and cardiac resynchronization therapy devices. Comparisons between apical and septal position were performed regarding R-wave amplitude, pacing threshold at a pulse width of 0.5 ms, pacing and shock lead impedance, suboptimal lead performance, left ventricular ejection fraction (LVEF), left ventricular end-diastolic diameter, readmissions due to heart failure and mortality rates. A total of 5 studies comprising 1438 patients were included in the analysis. Mean age was 64.5 years, 76.9% were male, with a median LVEF of 27.8%, ischemic etiology in 51.1%, and a mean follow-up period of 26.5 months. The apical lead placement was performed in 743 patients and septal lead placement in 690 patients. Comparing the 2 placement sites, no significant differences were found regarding R-wave amplitude, lead impedance, suboptimal lead performance, LVEF, left ventricular end-diastolic diameter, and mortality rate at 1-year follow-up. Pacing threshold values favored septal defibrillator lead placement ( P = 0.003), as well as shock impedance ( P = 0.009) and readmissions due to heart failure ( P = 0.02). Among patients receiving a defibrillator lead, only pacing threshold, shock lead impedance, and readmission due to heart failure showed results favoring septal lead placement. Therefore, generally, the right ventricle lead placement does not appear to be of major importance.

Myocardial work in idiopathic premature ventricular contractions: Assessing left ventricular function and prognosis

BACKGROUND

Premature ventricular contractions (PVCs) can lead to impairment of left ventricular function. The noninvasive myocardial work technique, which incorporates left ventricular afterload, represents a new method for assessing left ventricular functional.

AIM

The aim of this study is to explore the value of noninvasive myocardial work technique in assessing left ventricular systolic function in patients with PVCs.

METHODS

Compare the clinical data, two-dimensional echocardiography parameters, and myocardial work parameters of 66 patients with PVCs and 35 healthy volunteers and explore the relevant risk factors for postoperative recurrence in patients with PVCs.

RESULTS

In patients with PVCs compared to the control group, they exhibit enlargement of left atrial diameter (LAD) and left ventricular internal dimension in diastole (LVIDd), as well as thickening of the left ventricular wall. The global work waste (GWW) increases, while the global work efficiency (GWE) decreases. There is a significant negative correlation between the PVC burden and GWE (r = -0.70, p <0.01), and a significant positive correlation between the PVC burden and GWW (r = 0.58, p <0.01). GWE is a sensitive indicator for predicting the recurrence of PVCs after radiofrequency ablation. Patients with GWE <91.5%, global longitudinal strain (GLS) <15.5%, and ejection fraction (EF) <62.5% have a higher postoperative recurrence rate.

CONCLUSION

PVCs can cause impairment of left ventricular systolic function. GWE is the most sensitive indicator for predicting postoperative recurrence in patients with PVCs. Patients with GWE <91.5%, GLS <15.5%, and EF <62.5% have a higher postoperative recurrence rate.

MRI Assessment of Myocardial Deformation for Risk Stratification of Major Arrhythmic Events in Patients With Non-Ischemic Cardiomyopathy Eligible for Primary Prevention Implantable Cardioverter Defibrillators

BACKGROUND

Implantable cardioverter-defibrillator (ICD) intervention is an established prophylactic measure. Identifying high-benefit patients poses challenges.

PURPOSE

To assess the prognostic value of cardiac magnetic resonance imaging (MRI) parameters including myocardial deformation for risk stratification of ICD intervention in non-ischemic cardiomyopathy (NICM) while accounting for competing mortality risk.

STUDY TYPE

Retrospective and prospective.

POPULATION

One hundred and fifty-nine NICM patients eligible for primary ICD (117 male, 54 ± 13 years) and 49 control subjects (38 male, 53 ± 5 years).

FIELD STRENGTH/SEQUENCE

Balanced steady state free precession (bSSFP) and three-dimensional phase-sensitive inversion-recovery late gadolinium enhancement (LGE) sequences at 1.5 T or 3 T.

ASSESSMENT

Patients underwent MRI before ICD implantation and were followed up. Functional parameters, left ventricular global radial, circumferential and longitudinal strain, right ventricular free wall longitudinal strain (RV FWLS) and left atrial strain were measured (Circle, cvi42). LGE presence was assessed visually. The primary endpoint was appropriate ICD intervention. Models were developed to determine outcome, with and without accounting for competing risk (non-sudden cardiac death), and compared to a baseline model including LGE and clinical features.

STATISTICAL TESTS

Wilcoxon non-parametric test, Cox's proportional hazards regression, Fine-Gray competing risk model, and cumulative incidence functions. Harrell's c statistic was used for model selection. A P value <0.05 was considered statistically significant.

RESULTS

Follow-up duration was 1176 ± 960 days (median: 896). Twenty-six patients (16%) met the primary endpoint. RV FWLS demonstrated a significant difference between patients with and without events (-12.5% ± 5 vs. -16.4% ± 5.5). Univariable analyses showed LGE and RV FWLS were significantly associated with outcome (LGE: hazard ratio [HR] = 3.69, 95% CI = 1.28-10.62; RV FWLS: HR = 2.04, 95% CI = 1.30-3.22). RV FWLS significantly improved the prognostic value of baseline model and remained significant in multivariable analysis, accounting for competing risk (HR = 1.73, 95% CI = 1.12-2.66).

DATA CONCLUSIONS

In NICM, RV FWLS may provide additional predictive value for predicting appropriate ICD intervention.

LEVEL OF EVIDENCE

2 TECHNICAL EFFICACY: Stage 5.

Safety, efficacy, and reliability evaluation ofa novel small-diameter defibrillation lead: Global LEADR pivotal trial results

BACKGROUND

Implantable cardioverter-defibrillators last longer, and interest in reliable leads with targeted lead placement is growing. The OmniaSecure defibrillation lead is a novel, small-diameter, catheter-delivered lead designed for targeted placement, based on the established SelectSecure SureScan MRI Model 3830 lumenless pacing lead platform.

OBJECTIVE

This trial assessed safety and efficacy of the OmniaSecure defibrillation lead.

METHODS

The worldwide LEADR pivotal clinical trial enrolled patients indicated for de novo implantation of a primary or secondary prevention implantable cardioverter-defibrillator or cardiac resynchronization therapy defibrillator, all of whom received the study lead. The primary efficacy end point was successful defibrillation at implantation per protocol. The primary safety end point was freedom from study lead-related major complications at 6 months. The primary efficacy and safety objectives were met if the lower bound of the 2-sided 95% credible interval was >88% and >90%, respectively.

RESULTS

In total, 643 patients successfully received the study lead, and 505 patients have completed 12-month follow-up. The lead was placed in the desired right ventricular location in 99.5% of patients. Defibrillation testing at implantation was completed in 119 patients, with success in 97.5%. The Kaplan-Meier estimated freedom from study lead-related major complications was 97.1% at 6 and 12 months. The trial exceeded the primary efficacy and safety objective thresholds. There were zero study lead fractures and electrical performance was stable throughout the mean follow-up of 12.7 ± 4.8 months (mean ± SD).

CONCLUSION

The OmniaSecure lead exceeded prespecified primary end point performance goals for safety and efficacy, demonstrating high defibrillation success and a low occurrence of lead-related major complications with zero lead fractures.

Association of fatty liver index with sudden cardiac arrest in young adults

BACKGROUND

Metabolic dysfunction-associated steatotic liver disease (MASLD) contributes to cardiovascular events. Therefore, we aimed to identify the association of MASLD, as indicated by the fatty liver index (FLI), on sudden cardiac arrest (SCA) in young adults.

METHODS

We analyzed data from adults aged 20-39 years, who underwent health examinations between 2009 and 2012, sourced from the Korean National Health Insurance Service database. The presence of MASLD was determined using the FLI, which was calculated based on an individual's body mass index, waist circumference, gamma-glutamyl transferase and triglyceride levels. The primary outcome was the occurrence of SCA during the follow-up period, until December 2020.

RESULTS

Of the total 5,398,082 individuals analyzed, 4,021,056 (74.5 %) had a normal FLI (FLI <30), 837,943 (15.5 %) were within the intermediate range (30-60), and 539,083 (10.0 %) demonstrated a high FLI (≥60). Individuals with a high FLI were older, and comprised a higher proportion of men with hypertension, diabetes mellitus, dyslipidemia, heart failure, and myocardial infarction. During follow-up, SCA occurred in 4255 individuals (0.08 %). The group with a high FLI exhibited an increased incidence (incidence rate, 0.19) and elevated risk of SCA (hazard ratio, 3.04). Adjustment of covariates revealed a 55 % increased risk of SCA in the high FLI group (adjusted hazard ratio 1.55, 95 % confidence interval 1.41-1.70, p < 0.001). Moreover, the influence of a high FLI on SCA risk was more pronounced in women compared to men. Additionally, an increase in relevant cardiometabolic conditions was associated with an elevated risk of SCA.

CONCLUSIONS

Among young adults, a high risk of MASLD, as indicated by the FLI, revealed an increased risk of SCA. Furthermore, the association of FLI with the risk of SCA varied by sex and cardiometabolic conditions.

Prognostic value of non-invasive programmed ventricular stimulation after VT ablation to predict VT recurrences

BACKGROUND

The prognostic value of (non)-invasive programmed ventricular stimulation (NIPS) to predict recurrences of ventricular tachycardia (VT) is under discussion. Optimal endpoints of VT ablation are not well defined, and optimal timepoint of NIPS is unknown. The goal of this study was to evaluate the ability of programmed ventricular stimulation at the end of the VT ablation procedure (PVS) and NIPS after VT ablation to identify patients at high risk for VT recurrence.

METHODS

Between January 2016 and February 2022, consecutive patients with VT and structural heart disease undergoing first VT ablation and consecutive NIPS were included. In total, 138 patients were included. All patients underwent NIPS through their implanted ICDs after a median of 3 (1-5) days after ablation (at least 2 drive cycle lengths (500 and 400 ms) and up to four right ventricular extrastimuli until refractoriness). Clinical VT was defined by comparison with 12-lead electrocardiograms and stored ICD electrograms from spontaneous VT episodes. Patients were followed for a median of 37 (13-61) months.

RESULTS

Of the 138 patients, 104 were non-inducible (75%), 27 were inducible for non-clinical VTs (20%), and 7 for clinical VT (5%). In 107 patients (78%), concordant results of PVS and NIPS were observed. After 37 ± 20 months, the recurrence rate for any ventricular arrhythmia was 40% (normal NIPS 29% vs. inducible VT during NIPS 66%; log-rank p = 0.001) and for clinical VT was 3% (normal NIPS 1% vs. inducible VT during NIPS 9%; log-rank p = 0.045). Positive predictive value (PPV) and negative predictive value (NPV) of NIPS were higher compared to PVS (PPV: 65% vs. 46% and NPV: 68% vs. 61%). NIPS revealed the highest NPV among patients with ICM and LVEF > 35%. Patients with inducible VT during NIPS had the highest VT recurrences and overall mortality. Patients with both negative PVS and NIPS had the lowest any VT recurrence rates with 32%. Early re-ablation of patients with recurrent VTs during index hospitalization was feasible but did not reveal better long-term VT-free survival.

CONCLUSIONS

In patients after VT ablation and structural heart disease, NIPS is superior to post-ablation PVS to stratify the risk of VT recurrences. The PPV and NPV of NIPS at day 3 were superior compared to PVS at the end of the procedure to predict recurrent VT, especially in patients with ICM.

Outcome of Patients With Systolic Heart Failure Who Underwent Sympathectomy for Ventricular Arrhythmia

Cardiac sympathetic denervation (CSD) is a surgical procedure increasingly used for managing ventricular arrhythmia refractory to conventional medical therapy. Long-term outcomes of CSD in patients with systolic heart failure has not been well studied. This observational study aimed to evaluate the medical co-morbidities and outcomes of patients with systolic heart failure who underwent CSD performed as treatment for ventricular arrhythmia refractory to conventional therapy. A retrospective analysis in adult patients with ventricular arrhythmia and systolic heart failure who underwent unilateral or bilateral CSD at a single center was performed. Unadjusted Kaplan-Meier survival curves were constructed to evaluate survival after CSD. Between June 1, 2011 and March 31, 2021, 32 adult patients (age 62 ± 11.6 years, 88% male, left ventricular ejection fraction 22% ± 8.2%) with systolic heart failure underwent unilateral left (n = 4), unilateral right (n = 1), or bilateral CSD (n = 27). Mean survival after CSD was 613 ± 745 days, and the mean time from CSD to death was 291 ± 447 days. The cumulative probability of survival 1 year after CSD was 61.4%. In this single-center observational study, CSD performed for refractory ventricular arrhythmia showed favorable survival in patients with systolic heart failure. In conclusion, this study lays the groundwork for a more in-depth analysis of the potential survival benefits of CSD in this patient group.

Simultaneous prognostic score validation in patients with out-of-hospital cardiac arrest by a post-hoc analysis based on national multicenter registry

Using a nationwide multicenter prospective registry in Japan's data, we calculated prognostic and predictive scores, including the Out-of-Hospital Cardiac Arrest (OHCA); Cardiac Arrest Hospital Prognosis (CAHP); Nonshockable rhythm, Unwitnessed arrest, Long no-flow or Long low-flow period, blood PH < 7.2, Lactate > 7.0 mmol/L, End-stage chronic kidney disease on dialysis, Age ≥ 85 years, Still resuscitation, and Extracardiac cause (NULL-PLEASE); revised post-Cardiac Arrest Syndrome for Therapeutic hypothermia (rCAST); and MIRACLE2 scores, for adult patients with cardiac arrest. The MIRACLE2 score was validated with the modified MIRACLE2 score, which excludes information of pupillary reflexes. Each score was calculated only for the cases with no missing data for the variables used. These scores' accuracies were compared using neurological outcomes 30 days after out-of-hospital cardiac arrest (OOHCA). Patients with a cerebral performance category scale of 1 or 2 were designated as having favorable neurological outcomes. Each score's discrimination ability was evaluated by the receiver operating characteristic curve's area under the curve (AUC). To assess in detail in areas of high specificity and high sensitivity, which are areas of interest to clinicians, partial AUCs were also used. The analysis included 11,924 hospitalized adult patients. The AUCs of the OHCA, MIRACLE2, CAHP, rCAST, and NULL-PLEASE scores for favorable neurological outcomes were 0.713, 0.727, 0.785, 0.761, and 0.831, respectively. The CAHP and NULL-PLEASE scores were significantly more accurate than the rest. Accuracies did not differ significantly between the CAHP and NULL-PLEASE scores. The NULL-PLEASE score was significantly better at discriminating favorable neurological prognoses at 30 days in patients with OOHCA compared to other scoring systems.

Therapy duration and improvement of ventricular function in de novo heart failure: the Heart Failure Optimization study

BACKGROUND AND AIMS

In patients with de novo heart failure with reduced ejection fraction (HFrEF), improvement of left ventricular ejection fraction (LVEF) is expected to occur when started on guideline-recommended medical therapy. However, improvement may not be completed within 90 days.

METHODS

Patients with HFrEF and LVEF ≤ 35% prescribed a wearable cardioverter-defibrillator between 2017 and 2022 from 68 sites were enrolled, starting with a registry phase for 3 months and followed by a study phase up to 1 year. The primary endpoints were LVEF improvement > 35% between Days 90 and 180 following guideline-recommended medical therapy initiation and the percentage of target dose reached at Days 90 and 180.

RESULTS

A total of 598 patients with de novo HFrEF [59 years (interquartile range 51-68), 27% female] entered the study phase. During the first 180 days, a significant increase in dosage of beta-blockers, renin-angiotensin system inhibitors, and mineralocorticoid receptor antagonists was observed (P < .001). At Day 90, 46% [95% confidence interval (CI) 41%-50%] of study phase patients had LVEF improvement > 35%; 46% (95% CI 40%-52%) of those with persistently low LVEF at Day 90 had LVEF improvement > 35% by Day 180, increasing the total rate of improvement > 35% to 68% (95% CI 63%-72%). In 392 patients followed for 360 days, improvement > 35% was observed in 77% (95% CI 72%-81%) of the patients. Until Day 90, sustained ventricular tachyarrhythmias were observed in 24 wearable cardioverter-defibrillator carriers (1.8%). After 90 days, no sustained ventricular tachyarrhythmia occurred in wearable cardioverter-defibrillator carriers.

CONCLUSIONS

Continuous optimization of guideline-recommended medical therapy for at least 180 days in HFrEF is associated with additional LVEF improvement > 35%, allowing for better decision-making regarding preventive implantable cardioverter-defibrillator therapy.

Celastrol exerts antiarrhythmic effects in chronic heart failure via NLRP3/Caspase-1/IL-1β signaling pathway

OBJECTIVES

Celastrol has widespread therapeutic applications in various pathological conditions, including chronic inflammation. Previous studies have demonstrated the potent cardioprotective effects of celastrol. Nevertheless, limited attention has been given to its potential in reducing ventricular arrhythmias (VAs) following myocardial infarction (MI). Hence, this study aimed to elucidate the potential mechanisms underlying the regulatory effects of celastrol on VAs and cardiac electrophysiological parameters in rats after MI.

METHODS

Sprague-Dawley rats were divided at random: the sham, MI, and MI + celastrol groups. The left coronary artery was occluded in the MI and MI + Cel groups. Electrocardiogram, heart rate variability (HRV), ventricular electrophysiological parameters analysis, histology staining of ventricles, Enzyme-linked immunosorbent assay (ELISA), western blotting and Quantitative real-time polymerase chain reaction (qRT-PCR) were performed to elucidate the underlying mechanism of celastrol. Besides, H9c2 cells were subjected to hypoxic conditions to create an in vitro model of MI and then treated with celastrol for 24 hours. Nigericin was used to activate the NLRP3 inflammasome.

RESULTS

Compared with that MI group, cardiac electrophysiology instability was significantly alleviated in the MI + celastrol group. Additionally, celastrol improved HRV, upregulated the levels of Cx43, Kv.4.2, Kv4.3 and Cav1.2, mitigated myocardial fibrosis, and inhibited the NLRP3 inflammasome pathway. In vitro conditions also supported the regulatory effects of celastrol on the NLRP3 inflammasome pathway.

CONCLUSIONS

Celastrol could alleviate the adverse effects of VAs after MI partially by promoting autonomic nerve remodeling, ventricular electrical reconstruction and ion channel remodeling, and alleviating ventricular fibrosis and inflammatory responses partly by through inhibiting the NLRP3/Caspase-1/IL-1β pathway.

Development, validation and long-term evaluation of a liquid chromatography-tandem mass spectrometry method for simultaneous quantification of amiodarone, desethylamiodarone and mexiletine in human plasma and serum

Amiodarone and mexiletine are used for ventricular arrhythmias, for which a combination therapy of both anti-arrhythmic drugs (AADs) is not uncommon. Therapeutic drug monitoring (TDM) can be beneficial for clinical guidance of therapy, especially to correctly identify adverse events. Desethylamiodarone, the active metabolite of amiodarone, accumulates over time and is associated with serious adverse events. Therefore, simultaneous TDM for amiodarone, desethylamiodarone and mexiletine is advantageous in clinical practice. The presented LC-MS/MS method was validated for selectivity, matrix effect, linearity, accuracy, precision, carry-over and stability. The method was continuously evaluated during eight months of clinical use. The method was shown to be linear within the measured range of 0.1 to 10 mg/L for each component. The matrix effect was considered negligible. No interfering responses were found for amiodarone, desethylamiodarone and the isotopic-labeled internal standards. A constant and reproducible within-run contribution of 45.3 %, originating from the system, was identified for mexiletine. The systemic contribution to the peak area of the lowest quantifiable concentration of mexiletine affected the selectivity and carry-over effect measurements. Multiple measurements showed that regression adjusted concentrations were accurate and reproducible, indicating calibration correction was applicable. Sample stability was found to be within limits for all storage conditions and freeze-thaw cycles. Furthermore, long-term method evaluation with external controls resulted in stable measurements with a percentage coefficient of variance between 1.3 % and 6.3 %. The presented practical and reliable method is applicable for clinical TDM and will allow clinical practitioners to guide drug therapy of amiodarone and mexiletine.

Incidence, Predictors, and Outcome Associated With Ventricular Tachycardia or Fibrillation in Patients Undergoing Primary Percutaneous Coronary Intervention for Acute Myocardial Infarction

BACKGROUND

The characteristics and clinical outcomes associated with sustained ventricular tachycardia and fibrillation (VT/VF) in Japanese acute myocardial infarction (AMI) patients remain unknown.

METHODS AND RESULTS

Consecutive AMI patients (n=1,941) transferred to the Hirosaki University Hospital and treated with primary percutaneous coronary intervention (PCI) within 12 h of onset were retrospectively studied. The incidence of VT/VF during hospitalization was 8.3%, and 75% of cases occurred by the end of PCI. Independent predictors associated with VT/VF occurrence by the end of PCI and after PCI, respectively, were identified. Additionally, the differences between patients with VT and VF were examined, which revealed that the characteristics of patients and predictors for VT and VF were clearly different. Additionally, the QRS duration during VT was measured, which demonstrated the possible involvement of Purkinje fibers for VT in the acute phase of AMI. Of the patients with VT/VF, 12% required ECMO support due to refractory VT/VF despite intravenous antiarrhythmic agents such as β-blockers, amiodarone, and nifekalant. Among the patients discharged alive, 1,690 were followed up for a mean of 3.7 years. VT/VF occurrence during hospitalization did not affect the mid-term clinical outcomes even in patients with VT.

CONCLUSIONS

The results clearly indicated that VT/VF is still a serious complications of AMI. We need to identify patients at high risk of developing VT/VF for careful observation and appropriate intervention.

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.

Programmed Ventricular Stimulation: Risk Stratification and Guiding Antiarrhythmic Therapies

Electrophysiologic testing with programmed ventricular stimulation (PVS) has been utilized to induce ventricular tachycardia (VT), thereby improving risk stratification for patients with ischemic and nonischemic cardiomyopathies and determining the effectiveness of antiarrhythmic therapies, especially catheter ablation. A variety of procedural aspects can be modified during PVS in order to alter the sensitivity and specificity of the test including the addition of multiple baseline pacing cycle lengths, extrastimuli, and pacing locations. The definition of a positive result is also critically important, which has varied from exclusively sustained monomorphic VT (>30 seconds) to any ventricular arrhythmia regardless of morphology. In this review, we discuss the history of PVS and evaluate its role in sudden cardiac death risk stratification in a variety of patient populations. We propose an approach to future investigations that will capitalize on the unique ability to vary the sensitivity and specificity of this test. We then discuss the application of PVS during and following catheter ablation. The strategies that have been utilized to improve the efficacy of intraprocedural PVS are highlighted during a discussion of the limitations of this probabilistic strategy. The role of noninvasive programmed stimulation is also reviewed in predicting recurrent VT and informing management decisions including repeat ablations, modifications in antiarrhythmic drugs, and implantable cardioverter-defibrillator programming. Based on the available evidence and guidelines, we propose an approach to future investigations that will allow clinicians to optimize the use of PVS for risk stratification and assessment of therapeutic efficacy.

Cease the storm - Successful stellate ganglion block in terminating refractory electrical storm

An electrical storm also known as a ventricular tachycardia storm (VT storm) tends to recur and form a vicious cycle, eventually leading to a refractory electrical storm, refractory to electrical and pharmacological cardioversion. The treatment of refractory VT storm is challenging. Here we discuss the case of a middle-aged gentleman who presented to our emergency department 6 months apart with a refractory VT storm. When all the anti-arrhythmic agents and multiple cardioversion attempts failed in terminating the storm, we attempted ultrasound-guided stellate ganglion block. On both occasions, it successfully terminated the storm. Hence emergency physicians need to be aware of the right technique and timing of stellate ganglion block and ultrasound-guided needle tracking, as it can be a final rescue technique in treating refractory electrical storm in the emergency department.

Risk factors for mortality in post-myocardial infarction patients: insights from the improve SCA bridge study

BACKGROUND

Underutilization of implantable cardioverter defibrillators (ICD) to prevent sudden cardiac death (SCD) in post-myocardial infarction (MI) patients remains an issue across several geographies. A better understanding of risk factors for SCD in post-MI patients from regions with low ICD adoption rates will help identify those who will benefit from an ICD. This analysis assessed risk factors for all-cause and cardiovascular-related mortality in post-MI patients from the Improve Sudden Cardiac Arrest (SCA) Bridge Trial.

RESULTS

For the entire cohort, the overall 1-year mortality rate was 5.9% (88/1491) and 3.4% (51/1491) for all-cause and cardiovascular mortality, respectively, with 76.5% of all cardiac deaths being from SCD. A multivariate model determined increased age, reduced left ventricular ejection fraction (LVEF), increased time from myocardial infarction to hospital admission, being female, being from Southeast Asia (SEA), and having coronary artery disease to be significant risk factors for all-cause mortality. The risk factors for cardiovascular-related mortality revealed increased age, reduced LVEF, and being from SEA as significant risk factors.

CONCLUSIONS

We show several characteristics as being predictors of cardiovascular-related mortality in post-MI patients from the Improve SCA Bridge study. Patients who experience an MI and present with these characteristics would benefit from a referral to an electrophysiologist for further SCD risk stratification and management and possible subsequent ICD implantation to reduce unnecessary death.

Head-to-Head Comparison and Temporal Trends of Cardiac MRI Recommendations in ESC versus ACC/AHA Guidelines: A Systematic Review and Meta-Analysis

Purpose To provide a comprehensive head-to-head comparison and temporal analysis of cardiac MRI indications between the European Society of Cardiology (ESC) and American College of Cardiology/American Heart Association (ACC/AHA) guidelines to identify areas of consensus and divergence. Materials and Methods A systematic review and meta-analysis was conducted. ESC and ACC/AHA guidelines published until May 2023 were systematically screened for recommendations related to cardiac MRI. The class of recommendation (COR) and level of evidence (LOE) for cardiac MRI recommendations were compared between the two guidelines and between newer versus older versions of each guideline using χ2 or Fisher exact tests. Results ESC guidelines included 109 recommendations regarding cardiac MRI, and ACC/AHA guidelines included 90 recommendations. The proportion of COR I and LOE B was higher in ACC/AHA versus ESC guidelines (60% [54 of 90] vs 46.8% [51 of 109]; P = .06 and 53% [48 of 90] vs 35.8% [39 of 109], respectively; P = .01). The increase in the number of cardiac MRI recommendations over time was significantly higher in ESC guidelines (from 63 to 109 for ESC vs from 65 to 90 for ACC/AHA; P = .03). The main areas of consensus were found in heart failure and hypertrophic cardiomyopathy, while the main divergences were in valvular heart disease, arrhythmias, and aortic disease. Conclusion ESC guidelines included more recommendations related to cardiac MRI use, whereas the ACC/AHA recommendations had higher COR and LOE. The number of cardiac MRI recommendations increased significantly over time in both guidelines, indicating the increasing role of cardiac MRI evaluation and management of cardiovascular disease. Keywords: Cardiovascular Magnetic Resonance, Guideline, European Society of Cardiology, ESC, American College of Cardiology/American Heart Association, ACC/AHA Supplemental material is available for this article. © RSNA, 2024.

Increasing Knowledge about Implantable Cardioverter Defibrillators at the End of Life, an Effective Approach for Hospice Workers to Improve Patient Care

BACKGROUND

Implantable cardioverter defibrillators (ICDs) decrease mortality in high-risk patients but can also cause distressing shocks near death. Patients who lack knowledge about their ICDs are more likely to have an active device at the end of life. Many hospice workers lack sufficient knowledge to educate patients about ICDs.

MEASURES

An ICD educational video created for use in a diverse, underserved patient population was shown to hospice workers from two large community hospices and attendees of a regional conference. A validated 10 question survey was given to participants before and after the video.

OUTCOMES

Significant improvement in ICD knowledge scores was seen in all participants (W = 3119.5, P < 0.0001). While doctors and nurses showed higher pretest knowledge, post-test knowledge scores equalized across all participants.

CONCLUSIONS/LESSONS LEARNED

An ICD patient educational video designed for a diverse, underserved patient population effectively improved ICD knowledge to a uniform excellent level for a broad range of hospice workers.

Targeting NLRP3 signaling reduces myocarditis-induced arrhythmogenesis and cardiac remodeling

BACKGROUND

Myocarditis substantially increases the risk of ventricular arrhythmia. Approximately 30% of all ventricular arrhythmia cases in patients with myocarditis originate from the right ventricular outflow tract (RVOT). However, the role of NLRP3 signaling in RVOT arrhythmogenesis remains unclear.

METHODS

Rats with myosin peptide-induced myocarditis (experimental group) were treated with an NLRP3 inhibitor (MCC950; 10 mg/kg, daily for 14 days) or left untreated. Then, they were subjected to electrocardiography and echocardiography. Ventricular tissue samples were collected from each rat's RVOT, right ventricular apex (RVA), and left ventricle (LV) and examined through conventional microelectrode and histopathologic analyses. In addition, whole-cell patch-clamp recording, confocal fluorescence microscopy, and Western blotting were performed to evaluate ionic currents, intracellular Ca2+ transients, and Ca2+-modulated protein expression in individual myocytes isolated from the RVOTs.

RESULTS

The LV ejection fraction was lower and premature ventricular contraction frequency was higher in the experimental group than in the control group (rats not exposed to myosin peptide). Myocarditis increased the infiltration of inflammatory cells into cardiac tissue and upregulated the expression of NLRP3; these observations were more prominent in the RVOT and RVA than in the LV. Furthermore, experimental rats treated with MCC950 (treatment group) improved their LV ejection fraction and reduced the frequency of premature ventricular contraction. Histopathological analysis revealed higher incidence of abnormal automaticity and pacing-induced ventricular tachycardia in the RVOTs of the experimental group than in those of the control and treatment groups. However, the incidences of these conditions in the RVA and LV were similar across the groups. The RVOT myocytes of the experimental group exhibited lower Ca2+ levels in the sarcoplasmic reticulum, smaller intracellular Ca2+ transients, lower L-type Ca2+ currents, larger late Na+ currents, larger Na+-Ca2+ exchanger currents, higher reactive oxygen species levels, and higher Ca2+/calmodulin-dependent protein kinase II levels than did those of the control and treatment groups.

CONCLUSION

Myocarditis may increase the rate of RVOT arrhythmogenesis, possibly through electrical and structural remodeling. These changes may be mitigated by inhibiting NLRP3 signaling.

Ablation of epicardial ventricular focus through coronary sinus using pulsed-field ablation. A case report

INTRODUCTION

With the entry of pulsed-field ablation (PFA) into electrophysiology, new possibilities for ablation of different substrates such as epicardial foci of premature ventricular contractions (PVCs) from coronary venous system (CVS) have been opened.

METHODS

This article focuses on a case of a 27-year-old patient with frequent monomorphic PVCs of epicardial origin, treated by radiofrequency ablation, followed by PFA.

RESULTS

After unsuccessful focus ablation through CVS with RFA, successful ablations from the same region with PFA were achieved.

CONCLUSION

This is the first described case of successful ablation of epicardial PVCs using PFA, which we hope will help in defining indications for this novel technology and enhance quality of treatment for patients with different arrhythmias.

Thirty-day readmission after catheter ablation for ventricular tachycardia: associated factors and outcomes

BACKGROUND

Patients with ventricular tachycardia (VT) who require VT ablation are at high risk for readmission. This study aimed to identify the causes and outcomes of 30-day readmission after VT ablation and to analyze the predictors of recurrent VT that required rehospitalization.

METHODS

Using the Nationwide Readmission Database, our study included patients aged ≥ 18 years who underwent VT catheter ablation between 2017 and 2020. Based on the International Classification of Diseases, Tenth Revision, Clinical Modification (ICD-10-CM), we identified the causes of 30-day readmission by organ systems and analyzed their outcomes. Additional analysis was performed to determine the independent predictors of 30-day readmission for recurrent VT.

RESULTS

Of the 4228 patients who underwent VT ablation, 14.2% were readmitted within 30 days of the procedure. The most common cause of readmission was cardiac events (73.6%). Among the cardiac-related readmissions, recurrent VT (47.7%) and congestive heart failure (CHF) (12.9%) were the most common etiologies. Among the readmissions, patients readmitted for CHF had the highest rate of readmission mortality (9.2%). Of the patients readmitted within 30 days of the procedure, 278 patients (6.8%) were readmitted for recurrent VT. Via multivariable analysis, CHF (OR: 1.97; 95% CI: 1.12-3.47; P = 0.02) and non-elective index admissions (OR: 1.63; 95% CI: 1.04-2.55; P = 0.03) were identified as the independent predictors predictive of 30-day readmissions for recurrent VT.

CONCLUSIONS

Recurrent VT was the most common cause of readmission after the VT ablation procedure, and CHF and non-elective index admissions were the significant predictors of these early readmissions. Readmission due to CHF had the highest mortality rate during readmission.

New Guidelines of Pediatric Cardiac Implantable Electronic Devices: What Is Changing in Clinical Practice?

Guidelines are important tools to guide the diagnosis and treatment of patients to improve the decision-making process of health professionals. They are periodically updated according to new evidence. Four new Guidelines in 2021, 2022 and 2023 referred to pediatric pacing and defibrillation. There are some relevant changes in permanent pacing. In patients with atrioventricular block, the heart rate limit in which pacemaker implantation is recommended was decreased to reduce too-early device implantation. However, it was underlined that the heart rate criterion is not absolute, as signs or symptoms of hemodynamically not tolerated bradycardia may even occur at higher rates. In sinus node dysfunction, symptomatic bradycardia is the most relevant recommendation for pacing. Physiological pacing is increasingly used and recommended when the amount of ventricular pacing is presumed to be high. New recommendations suggest that loop recorders may guide the management of inherited arrhythmia syndromes and may be useful for severe but not frequent palpitations. Regarding defibrillator implantation, the main changes are in primary prevention recommendations. In hypertrophic cardiomyopathy, pediatric risk calculators have been included in the Guidelines. In dilated cardiomyopathy, due to the rarity of sudden cardiac death in pediatric age, low ejection fraction criteria were demoted to class II. In long QT syndrome, new criteria included severely prolonged QTc with different limits according to genotype, and some specific mutations. In arrhythmogenic cardiomyopathy, hemodynamically tolerated ventricular tachycardia and arrhythmic syncope were downgraded to class II recommendation. In conclusion, these new Guidelines aim to assess all aspects of cardiac implantable electronic devices and improve treatment strategies.

A wearable telehealth system for the monitoring of parameters related to heart failure

Heart failure is a cardiovascular disease in which heart fails to pump sufficient blood required by the body. Significant signs of worsening heart failure include decreased thoracic impedance, increased heart rate, irregular electrocardiogram (ECG), and lack of motion activity of the patient. Heart failure can be better managed if monitored continuously and in real-time. The existing solutions for continuous monitoring of these parameters are invasive and hence are not only expensive but can also cause serious health risks. This paper discusses the development of a telehealth system that consists of an Internet of Things including a wearable device connected to a cloud-based database and a mobile application using Wi-Fi. The wearable device is a noninvasive monitor that consists of different sensors embedded with a microcontroller and can be a potential solution for better management of heart failure. It continuously monitors the above-mentioned parameters and sends data to the mobile application using a cloud-based system. The mobile application has separate portals for patients and doctors where doctor can monitor a specific patient enrolled under his profile. The performance of the developed device is validated in 10 healthy individuals.

Expanded application of wearable cardioverter defibrillators beyond current guidelines: proposal for a European register explained through single clinical scenarios

The wearable cardioverter defibrillator (WCD) is becoming a more and more widely used instrument for the prevention of sudden cardiac death of patients either with a secondary prevention implantable cardioverter defibrillator indication or with a transient high risk of sudden cardiac death. Although clinical practice has demonstrated a benefit of protecting patients for a period as long as 3-6 months with such devices, the current European guidelines concerning ventricular arrhythmias and sudden cardiac death are still extremely restrictive in the patient selection in part because of the costs derived from such a prevention device, in part because of the lack of robust randomised trials.To illustrate expanded use cases for the WCD, four real-life clinical cases are presented where patients received the device slightly outside the established guidelines. These cases demonstrate the broader utility of WCDs in situations involving acute myocarditis, thyrotoxicosis, pre-excited atrial fibrillation and awaiting staging/prognosis of a lung tumour. The findings prompt expansion of the existing guidelines for WCD use to efficiently protect more patients whose risk of arrhythmic cardiac death is transient or uncertain. This could be achieved by establishing a European register of the patients who receive a WCD for further analysis.

Torsade de pointes secondary to long QT syndrome after intragastric balloon placement. A rare but severe complication

The obesity pandemic is becoming one of the most prevalent diseases nowadays. There is a wide spectrum of treatment, ranging from hygienic-dietary measures to bariatric surgery. Endoscopic intragastric balloon placement is becoming increasingly more frequent, due to its technical simplicity, safety and short-term success(1). Although complications are rare some can be severe, so pre-endoscopic evaluation must be carried out carefully. A 43-year-old woman with a history of grade I obesity (BMI 32.7) had an Orbera® intragastric balloon implanted successfully. After the procedure she presented frequent nausea and vomiting, partially controlled with antiemetics. She attended the Emergency Department(ED) with a persistent emetic syndrome - oral intolerance and short-term loss of consciousness(syncope), for which she was admitted. Lab tests showed metabolic alkalosis with severe hypokalemia(K+ 1.8mmol/L), so fluid therapy was initiated for hydroelectrolytic replacement. During the patient's stay in the ED, two episodes of polymorphic ventricular tachychardia "Torsades de Pointes" (PVT-TDP) occurred, leading to cardiac arrest and requiring electrical cardioversion to restore sinus rhythm, in addition to a temporary pacemaker placement. Telemetry showed a corrected QT interval of >500ms, compatible with Long QT Syndrome(LQTS). Once the patient was hemodynamically stabilized a gastroscopy was performed. The intragastric balloon located in the fundus was removed using an extraction kit, puncturing and aspirating 500ml of saline solution, and extracting the collapsed balloon without any complications. The patient achieved an adequate oral intake afterwards, and no recurrence of emetic episodes were noticed. Previous ECGs revealed a prolonged QT interval and a genetic study confirmed a congenital type 1 LQTS. Treatment was initiated with beta-blockers and a bicameral automatic defibrillator was implanted in order to prevent recurrences. Intragastric balloon placement is generally a safe procedure, serious complications present in 0.70% of cases(2). It is essential to have a proper pre-endoscopic evaluation, including patient's medical history and comorbidities. Episodes of PVT-TDP may present precipitated by certain medications (eg. metoclopramide) or hydroelectrolytic imbalances (eg, hypokalemia)(3). A standardized evaluation of ECG before intragastric balloon placement may be useful to prevent these rare but serious complications.

Metabolomics Profiling Predicts Ventricular Arrhythmia in Patients with an Implantable Cardioverter Defibrillator

Implantable cardioverter defibrillators (ICDs) reduce sudden cardiac death (SCD) when patients experience life-threatening ventricular arrhythmias (LTVA). However, current strategies determining ICD patient selection and risk stratification are inefficient. We used metabolomics to assess whether dysregulated metabolites are associated with LTVA and identify potential biomarkers. Baseline plasma samples were collected from 72 patients receiving ICDs. Over a median follow-up of 524.0 days (range 239.0-705.5), LTVA occurred in 23 (31.9%) patients (22 effective ICD treatments and 1 SCD). After confounding risk factors adjustment for age, smoking, secondary prevention, and creatine kinase MB, 23 metabolites were significantly associated with LTVA. Pathway analysis revealed LTVA associations with disrupted metabolism of glycine, serine, threonine, and branched chain amino acids. Pathway enrichment analysis identified a panel of 6 metabolites that potentially predicted LTVA, with an area under the receiver operating characteristic curve of 0.8. Future studies are necessary on biological mechanisms and potential clinical use.

Low-intensity pulsed ultrasound treatment mitigates ventricular arrhythmias via inhibiting microglia-mediated neuroinflammation in heart failure rat model

BACKGROUND

Sympathetic overactivation plays an important role in heart failure (HF)-induced ventricular arrhythmias (VAs). Microglia-mediated neuroinflammation could contribute to sympathetic overactivation. A previous study demonstrated that low-intensity pulsed ultrasound (LIPUS) could inhibit neuroinflammation. However, whether LIPUS could attenuate HF-induced VAs via inhibiting microglia-mediated neuroinflammation remains largely unknown.

METHODS

Forth Sprague-Dawley male rats were averagely randomized into four groups: CTL (control) group, CTL + LIPUS group, HF group and HF + LIPUS. Surgical ligation of the coronary artery was used for induction of HF. In vivo electrophysiological study was performed to check VAs susceptibility. Left stellate ganglion (LSG) neural activity and heart rate variability (HRV) were used to test sympathetic nerve activity.

RESULTS

Compared to the HF group, LIPUS treatment significantly ameliorated HF-induced cardiac hypertrophy, fibrosis, and dysfunction. In addition, LIPUS treatment markedly inhibited HF-induced VAs susceptibility and reversed gap junction remodeling. LIPUS treatment obviously inhibited microglial activation and neuroinflammation in PVN, sympathetic hyperactivity in the LSG and proinflammatory cytokines releases in the ventricle. P2X7/NLRP3 signaling pathway may be involved in the anti-arrhythmic effect of LIPUS treatment following HF.

CONCLUSIONS

Our data demonstrated that LIPUS treatment protected against HF-induced VAs via alleviating microglia-mediated neuroinflammation, sympathetic overactivation and proinflammatory cytokines releases through inhibiting P2X7/NLRP3 signaling. This study provides novel insight into the therapeutic potential of LIPUS.

Cardiac stereotactic radiation therapy for refractory ventricular arrhythmias in patients with left ventricular assist devices

Left ventricular assist device (LVAD) implantation is an established treatment for patients with advanced heart failure refractory to medical therapy. However, the incidence of ventricular arrhythmias (VAs) is high in this population, both in the acute and delayed phases after implantation. About one-third of patients implanted with an LVAD will experience sustained VAs, predisposing these patients to worse outcomes and complicating patient management. The combination of pre-existing myocardial substrate and complex electrical remodeling after LVAD implantation account for the high incidence of VAs observed in this population. LVAD patients presenting VAs refractory to antiarrhythmic therapy and catheter ablation procedures are not rare. In such patients, treatment options are extremely limited. Stereotactic body radiation therapy (SBRT) is a technique that delivers precise and high doses of radiation to highly defined targets, reducing exposure to adjacent normal tissue. Cardiac SBRT has recently emerged as a promising alternative with a growing number of case series reporting the effectiveness of the technique in reducing the VA burden in patients with arrhythmias refractory to conventional therapies. The safety profile of cardiac SBRT also appears favorable, even though the current clinical experience remains limited. The use of cardiac SBRT for the treatment of refractory VAs in patients implanted with an LVAD are even more scarce. This review summarizes the clinical experience of cardiac SBRT in LVAD patients and describes technical considerations related to the implementation of the SBRT procedure in the presence of an LVAD.

Reversed Septal Curvature Is Associated With Nonsustained Ventricular Tachycardia in Hypertrophic Cardiomyopathy

Sudden cardiac death (SCD) is associated with nonsustained ventricular tachycardia (NSVT) in patients with hypertrophic cardiomyopathy (HCM). Recently, differences regarding septal morphology have been reported, with an increased probability of sudden death in patients with HCM who had reverse septal curvature (RSC). This study aimed to examine the relation between RSC and NSVT in HCM. A total of 138 patients with HCM were enrolled. Of 138 patients, 47 (34.1%) were diagnosed with RSC and 42 patients (30.4%) had NSVT. Compared with the non-RSC group, those with RSC were much younger and had an increased incidence of NSVT, thicker septal thickness, larger mass, and a higher proportion of HCM or SCD family history. Furthermore, patients with RSC had a higher risk of SCD according to the European Society of Cardiology calculator (2.5 [1.6 to 4.6] vs 1.6 [1.1 to 2.3] [%/5 years], p <0.001). The multivariate analysis showed that RSC was a strong and independent risk factor for NSVT (odds ratio 2.756, 95% confidence interval 1.164 to 6.525, p = 0.021). In conclusion, the presence of RSC in patients with HCM is independently associated with NSVT. Further studies are needed to evaluate the role of RSC as a risk factor for SCD in this population.

Safety and Performance of the Subcutaneous Implantable Cardioverter Defibrillator Detection Algorithm INSIGHTTM in Pacemaker Patients

BACKGROUND

The use of the S-ICD is limited by its inability to provide backup pacing. Combined use of the S-ICD with a pacemaker may be a good choice in certain situations, yet current experience concerning the compatibility is limited. The goal of this study was to determine the safety and efficacy of the S-ICD in patients with a pacemaker.

METHODS

A total of 74 consecutive patients with a bipolar pacemaker were prospectively enrolled. First, surface rhythm strips were recorded in all possible pacemaker stimulation modes, to screen for T-wave oversensing (TWOS). Second, a S-ICD functional dummy was placed epicutaneously on the patient in the typical implant position. The same standardized pacing protocol was used as mentioned above, and every stimulation mode was recorded via S-ECG in all vectors.

RESULTS

In 16 patients (21.6%), programmed stimulation would have led to VT/VF detection. Triggered episodes were due to counting of the pacing spike(s), QRS complex, premature ventricular contractions, and/or additional TWOS. Three cases triggered in the bipolar stimulation mode. Oversensing was associated with lung emphysema and a reduced QRS amplitude in the S-ECG.

CONCLUSION

The combination of an S-ICD and a pacemaker may lead to inadequate shock delivery due to oversensing, even under programmed bipolar stimulation. Oversensing cannot be sufficiently predicted by the screening tool in pacemaker patients. Testing with an epicutaneous S-ICD dummy in all vectors and stimulation settings is recommended in patients with pre-existing pacemakers.

Clinical and Genetic Features of Korean Inherited Arrhythmia Probands

BACKGROUND AND OBJECTIVES

Inherited arrhythmia (IA) is a more common cause of sudden cardiac death in Asian population, but little is known about the genetic background of Asian IA probands. We aimed to investigate the clinical characteristics and analyze the genetic underpinnings of IA in a Korean cohort.

METHODS

This study was conducted in a multicenter cohort of the Korean IA Registry from 2014 to 2017. Genetic testing was performed using a next-generation sequencing panel including 174 causative genes of cardiovascular disease.

RESULTS

Among the 265 IA probands, idiopathic ventricular fibrillation (IVF) and Brugada Syndrome (BrS) was the most prevalent diseases (96 and 95 cases respectively), followed by long QT syndrome (LQTS, n=54). Two-hundred-sixteen probands underwent genetic testing, and 69 probands (31.9%) were detected with genetic variant, with yield of pathogenic or likely pathogenic variant as 6.4%. Left ventricular ejection fraction was significantly lower in genotype positive probands (54.7±11.3 vs. 59.3±9.2%, p=0.005). IVF probands showed highest yield of positive genotype (54.0%), followed by LQTS (23.8%), and BrS (19.5%).

CONCLUSIONS

There were significant differences in clinical characteristics and genetic yields among BrS, LQTS, and IVF. Genetic testing did not provide better yield for BrS and LQTS. On the other hand, in IVF, genetic testing using multiple gene panel might enable the molecular diagnosis of concealed genotype, which may alter future clinical diagnosis and management strategies.

From organ at risk to target organ: Dosimetric comparison of myocardial stereotactic ablative body radiotherapy between helical tomotherapy and volumetric arc therapy for refractory ventricular tachycardia

Ventricular tachycardia (VT) is an important type of arrhythmia with a risk of sudden death. Although implanted cardiac defibrillation and radiofrequency ablation are used together with medical treatments for VT, the treatment options are limited in cases that do not respond to them. Stereotactic ablative body radiotherapy (SABR) applied to VT substrates in resistant cases is an emerging treatment with positive results. Such clinical results have increased the interest in this subject. However, the ideal treatment device and method have not yet been described for this therapy, which is generally applied at a single fraction using various devices and methods. Herein, treatment planning was conducted for a total of 8 patients (11 VT substrates) using the Varian TrueBeam EDGE and TomoTherapy Radixact devices at a single center, and the results were compared dosimetrically. The Wilcoxon-signed rank test was used for the statistical analysis, and mean values were expressed as medians and interquartile ranges (IQRs). In the volumetric modulated arc therapy (VMAT) and helical tomotherapy (HT) plans, the plan coverages and conformity indexes were similar; meanwhile, the homogeneity indexes were 0.10 (IQR = 0.05) and 0.07 (IQR = 0.05), respectively, and were significantly better in the HT plan (p = 0.02). The gradient indexes were 3.18 (IQR = 0.8) and 5.33 (IQR = 3.68) in the VMAT and HT plans, respectively, and were significantly better in the VMAT plan. For the organs at risk, similar doses were observed. The maximum doses for the stomach and esophagus and the mean doses for the left lung and both lungs were significantly lower in the VMAT plan. Similarly, the maximum and mean doses for the cardiac substructures and great vessels were significantly lower in the VMAT plan. More homogeneous plans were obtained in HT, while a faster dose reduction and lower critical organ dose were observed in VMAT. Reasonable myocardial SABR plans could be obtained with both techniques. The effects of the dosimetric differences on the clinical outcomes should be evaluated in prospective clinical studies.

Ischemic or Coronary Evaluations in Patients With Monomorphic VT Electrical Storm Undergoing VT Ablation

BACKGROUND

Monomorphic ventricular tachycardia (VT) electrical storm (ES) in patients with coronary artery disease is dependent on scarred myocardium. The role of routine ischemic or coronary evaluations before ablation in patients presenting with monomorphic VT storm, without acute coronary syndrome (ACS), remains unknown.

OBJECTIVES

This study sought to assess the impact of ischemic or coronary evaluations on procedural outcomes and post-ablation mortality in monomorphic VT storm patients.

METHODS

All patients undergoing VT ablation at the Cleveland Clinic from 2014 to 2020 after presenting with monomorphic VT storm were enrolled in a prospectively maintained registry. The associations among ischemic or coronary evaluations and short-term procedural efficacy, acute outcomes, and mortality during follow-up were assessed.

RESULTS

A total of 97 consecutive patients with monomorphic VT storm in the absence of ACS underwent VT ablations. This cohort was characterized by severe LV systolic dysfunction (mean left ventricular ejection fraction 30.3%, 67% with known ischemic cardiomyopathy) with moderately severe heart failure (median NYHA functional class II); 45% of patients underwent ischemic or coronary evaluations via coronary angiography (10%), noninvasive myocardial perfusion (26%), or both (9%). The yield of these evaluations was low: No acute coronary occlusions were identified. There was no association between ischemic evaluation and acute ablation outcomes or mortality during follow-up. Similarly, in a secondary analysis, the yield of ischemic or coronary evaluations in patients with monomorphic VT storm and known coronary disease (regardless of ablation status) was found to be low.

CONCLUSIONS

Ischemic evaluations in patients with monomorphic VT storm without ACS may not improve procedural outcomes or mortality after ablation.

Catecholaminergic Polymorphic Ventricular Tachycardia: A Review of Therapeutic Strategies

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by bidirectional or polymorphic ventricular arrhythmia provoked by exercise or emotion. Most cases are caused by pathogenic variants in the gene encoding the cardiac ryanodine receptor (RYR2). The options for treating patients with CPVT have increased during the years, and evidence suggests that these have led to lower arrhythmic event rates. In addition, numerous potential new therapies are being investigated. In this review, we summarize the state of knowledge on both established and potential future treatment strategies for patients with CPVT and describe our approach to their management.

Alternatives to transvenous lead placement in a patient undergoing surgical tricuspid valve repair

Tricuspid regurgitation is a widely recognised phenomenon in patients with transvenous cardiac rhythm management (CRM) devices. If tricuspid valve repair or replacement is to be considered, what to do with the existing CRM system requires scrutiny with multidisciplinary input. We present a case of multifactorial tricuspid regurgitation in a 48-year-old female with giant cell myocarditis and a transvenous implantable cardioverter-defibrillator (ICD). Key considerations in management and alternative CRM options are discussed.

Prognostic impact of morphology and duration of premature ventricular contractions in a population without structural heart disease

BACKGROUND

Premature ventricular contractions (PVCs) are a common form of arrhythmia associated with an unfavorable prognosis in patients with structural heart disease. It is unclear whether PVCs site of origin and QRS-width has a prognostic significance in patients without structural heart disease. The aim of this study was to assess the prognostic importance of PVCs morphology and duration in this patient group.

METHODS

We included 511 consecutive patients without a history of previous heart disease. They were examined with echocardiography and exercise test with normal findings. We categorized the PVCs from a 12 lead ECG according to morphology and width of the QRS-complex and analyzed the outcome in terms of a composite endpoint of total mortality and cardiovascular morbidity.

RESULTS

During a median follow-up time of 5.3 years, 19 patients (3.5%) died and 61 (11.3%) met the composite outcome. Patients with PVCs originating from the outflow tracts had a significantly lower risk for the composite outcome compared to patients with non-OT-PVCs. Similarly, patients with PVC originating from the right ventricle had a better outcome than patients with left ventricular PCVs. No difference in outcome depending on QRS-width during PVCs was noticed.

CONCLUSION

In our cohort of consecutively included PVC patients without structural heart disease PVCs from the outflow tracts were associated with a better prognostic outcome than non-OT PVCs; the same was true for right ventricular PVCs when compared to left ventricular ones. The classification of the origin of the PVCs was based on 12-lead ECG morphology. QRS-width during PVC did not seem to have prognostic significance.

The Rare Condition of Left Ventricular Non-Compaction and Reverse Remodeling

Left ventricular non-compaction (LVNC) is a rare disease defined by morphological criteria, consisting of a two-layered ventricular wall, a thin compacted epicardial layer, and a thick hyper-trabeculated myocardium layer with deep recesses. Controversies still exist regarding whether it is a distinct cardiomyopathy (CM) or a morphological trait of different conditions. This review analyzes data from the literature regarding diagnosis, treatment, and prognosis in LVNC and the current knowledge regarding reverse remodeling in this form of CM. Furthermore, for clear exemplification, we report a case of a 41-year-old male who presented symptoms of heart failure (HF). LVNC CM was suspected at the time of transthoracic echocardiography and was subsequently confirmed upon cardiac magnetic resonance imaging. A favorable remodeling and clinical outcome were registered after including an angiotensin receptor neprilysin inhibitor in the HF treatment. LVNC remains a heterogenous CM, and although a favorable outcome is not commonly encountered, some patients respond well to therapy.