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

m6A methyltransferase METTL3 participated in sympathetic neural remodeling post-MI via the TRAF6/NF-κB pathway and ROS production

OBJECTIVE

Sudden cardiac death caused by ventricular arrhythmias (VAs) is the main cause of high mortality in patients with myocardial infarction (MI). Sympathetic neural remodeling caused by inflammation after MI is closely associated with the occurrence of VAs. METTL3, the earliest identified m⁶A methyltransferase, is critical in mediating inflammatory responses. Our aim was to investigate whether the m⁶A methyltransferase METTL3 was involved in sympathetic remodeling post-MI and its specific mechanism.

METHODS AND RESULTS

A rat MI model was established via left coronary artery ligation. The expression of METTL3, TRAF6, NOX2, and NF-κB increased at 3 days and remained elevated at 7 days after MI, as determined via Western blotting. METTL3 was primarily present in macrophages, as determined via immunofluorescence. Intramyocardial injection of lentivirus carrying METTL3-shRNA inhibited METTL3 expression in vivo. Methylated immunoprecipitation-qPCR determined the METTL3 knockdown inhibited the m⁶A level of TRAF6 mRNA 3'-UTR. The co-immunoprecipitation experiment proved that METTL3 combines with TRAF6. Western blotting showed that silencing METTL3 inhibited TRAF6 level, NF-κB activation, and ROS production; decreased cytokine release (TNF-α and IL-1β); and downregulated nerve growth factor expression. Finally, METTL3 knockdown reduced sympathetic remodeling after MI, as determined via immunofluorescence assays of tyrosine hydroxylase and growth-associated protein 43. Programmed electrical stimulation, renal sympathetic nerve activity recording, and haemodynamic measurements showed that METTL3 inhibition decreased sympathetic activity and improved cardiac function.

CONCLUSIONS

Downregulation of METTL3 expression attenuated the excessive sympathetic neural remodeling induced by MI, further reducing the incidence of VAs and improving cardiac function. This was partly associated with the inhibition of the TRAF6/NF-κB pathway and ROS production.

Long-term prognosis of successful left ventricular substrate modification of electrical storm

Introduction

The Electrical storm (ES) subsumes a state of electrical instability of the heart, which manifests itself in repeated and potentially fatal ventricular arrhythmias (VA). We examine the long-term effects of substrate modification with regards to mortality, ventricular tachycardia (VT) recurrences and hospitalization depending on age, gender, heart function, scare location, VT documentation, postprocedural electrical stimulation (PES) and induced VTs.

Methods

From 08/2008 and 09/2019 160 consecutive patients admitted for ES ablation via electroanatomical mapping were followed up until 04/2021.

Results

50/160 patients showed VT recurrences after 13.8 ± 21.7 (0.0-80.3) months, with a characteristic steep curve directly after ES and then a rapid decline leading to a plateau (first month 10/50 (20%), first year 35/50 VT recurrences (70%) Mortality rates followed a similar pattern also the initial decline was not as steep. 42 patients died during the observation period (26%) after 16.6 ± 16.1 (0.0-67.9) months after ablation day (first month (n = 7, 16.7%) first year (n = 21, 50%). Gender, age, scare localization, missing VT documentation did not worsen outcome. Induction of >3 VTs and lack of PES due to hemodynamic instability significantly decreased effectiveness. Finding the entry significantly increased long-term effects.

Conclusion

Ablation of ES is safe and feasible independent of a variety of factors. Employing more sophisticated tools to understand the reentry mechanism will further improve the long-term outcome.

Ventricular arrhythmia and sudden cardiac death in hypertrophic cardiomyopathy: From bench to bedside

Patients with hypertrophic cardiomyopathy (HCM) mostly experience minimal symptoms throughout their lifetime, and some individuals have an increased risk of ventricular arrhythmias and sudden cardiac death (SCD). How to identify patients with a higher risk of ventricular arrythmias and SCD is the priority in HCM research. The American College of Cardiology/American Heart Association (ACC/AHA) and the European Society of Cardiology (ESC) both recommend the use of risk algorithms to identify patients at high risk of ventricular arrhythmias, to be selected for implantation of implantable cardioverters/defibrillators (ICDs) for primary prevention of SCD, although major discrepancies exist. The present SCD risk scoring systems cannot accurately identify early-stage HCM patients with modest structural remodeling and mild disease manifestations. Unfortunately, SCD events could occur in young asymptomatic HCM patients and even as initial symptoms, prompting the determination of new risk factors for SCD. This review summarizes the studies based on patients' surgical specimens, transgenic animals, and patient-derived induced pluripotent stem cells (hiPSCs) to explore the possible molecular mechanism of ventricular arrhythmia and SCD. Ion channel remodeling, Ca2+ homeostasis abnormalities, and increased myofilament Ca2+ sensitivity may contribute to changes in action potential duration (APD), reentry circuit formation, and trigger activities, such as early aferdepolarization (EAD) or delayed afterdepolarization (DAD), leading to ventricular arrhythmia in HCM. Besides the ICD implantation, novel drugs represented by the late sodium current channel inhibitor and myosin inhibitor also shed light on the prevention of HCM-related arrhythmias. The ideal prevention strategy of SCD in early-stage HCM patients needs to be combined with gene screening, hiPSC-CM testing, machine learning, and advanced ECG studies, thus achieving individualized SCD prevention.

Carvedilol versus Metoprolol in Patients with Ventricular Tachyarrhythmias

The study investigates the prognostic role of treatment with carvedilol as compared to metoprolol in patients with ventricular tachyarrhythmias. A large retrospective registry was used including consecutive patients on beta-blocker (BB) treatment with episodes of ventricular tachycardia (VT) or fibrillation (VF) from 2002 to 2015. Patients treated with carvedilol were compared to patients with metoprolol. The primary prognostic outcome was all-cause mortality at three years. Secondary endpoints comprised a composite arrhythmic endpoint (i.e., recurrences of ventricular tachyarrhythmias, appropriate implantable cardioverter defibrillator (ICD) therapies) and cardiac rehospitalization. Kaplan–Meier survival curves, multivariable Cox regression analyses, and propensity score matching were applied for statistics. There were 1098 patients included, 80% treated with metoprolol and 20% with carvedilol. Patients with carvedilol were older, more often presenting with VT (78% vs. 62%; p = 0.001) and with more advanced stages of heart failure. Treatment with carvedilol was associated with comparable all-cause mortality compared to metoprolol (20% vs. 16%, log rank p = 0.234; HR = 1.229; 95% CI 0.874–1.728; p = 0.235). However, secondary endpoints (i.e., composite arrhythmic endpoint: 32% vs. 17%; p = 0.001 and cardiac rehospitalization: 25% vs. 14%; p = 0.001) were more frequently observed in patients with carvedilol, which was still evident after multivariable adjustment. After propensity score matching (n = 194 patients with carvedilol and metoprolol), no further differences regarding the distribution of baseline characteristics were observed. Within the propensity-score-matched cohort, higher rates of the composite arrhythmic endpoint were still observed in patients treated with carvedilol, whereas the risk of cardiac rehospitalization was not affected by the type of beta-blocker treatment. In conclusion, carvedilol and metoprolol are associated with comparable all-cause mortality in patients with ventricular tachyarrhythmias, whereas the risk of the composite arrhythmic endpoint was increased in patients with carvedilol therapy.

Predictors of late arrhythmic events after generator replacement in Brugada syndrome treated with prophylactic ICD

Introduction

Predictors of late life-threatening arrhythmic events in Brugada syndrome (BrS) patients who received a prophylactic ICD implantation remain to be evaluated. The aim of the present long-term multicenter study was to assess the incidence and clinical-electrocardiographic predictors of late life-threatening arrhythmic events in BrS patients with a prophylactic implantable cardioverter defibrillator (ICD) and undergoing generator replacement (GR).

Methods

The study population included 105 patients (75% males; mean age 45 ± 14years) who received a prophylactic ICD and had no arrhythmic event up to first GR.

Results

The median period from first ICD implantation to last follow-up was 155 (128-181) months and from first ICD Implantation to the GR was 84 (61-102) months. During a median follow-up of 57 (38-102) months after GR, 10 patients (9%) received successful appropriate ICD intervention (1.6%/year). ICD interventions included shock on ventricular fibrillation (n = 8 patients), shock on ventricular tachycardia (n = 1 patient), and antitachycardia pacing on ventricular tachycardia (n = 1 patient). At survival analysis, history of atrial fibrillation (log-rank test; P = 0.02), conduction disturbances (log-rank test; P < 0.01), S wave in lead I (log-rank test; P = 0.01) and first-degree atrioventricular block (log-rank test; P = 0.04) were significantly associated with the occurrence of late appropriate ICD intervention. At Cox-regression multivariate analysis, S-wave in lead I was the only independent predictor of late appropriate ICD intervention (HR: 9.17; 95%CI: 1.15-73.07; P = 0.03).

Conclusions

The present study indicates that BrS patient receiving a prophylactic ICD may experience late appropriate intervention after GR in a clinically relevant proportion of cases. S-wave in lead I at the time of first clinical evaluation was the only independent predictor of persistent risk of life-threatening arrhythmic events. These findings support the need for GR at the end of service regardless of previous appropriate intervention, mostly in BrS patients with conduction abnormalities.

Emerging Genotype-Phenotype Associations in Dilated Cardiomyopathy

PURPOSE OF REVIEW

The disease burden of inherited dilated cardiomyopathy (DCM) is large and likely underestimated. This population stands to benefit immensely from therapeutic approaches tailored to the underlying genetic causes. Here, we review recent advances in understanding novel genotype-phenotype relationships and how these can improve the care of patients with inherited DCM.

RECENT FINDINGS

In the last several years, discovery of novel DCM-associated genes, gene-specific DCM outcomes, and nuanced information about variant-environment interactions have advanced our understanding of inherited DCM. Specifically, novel associations of genes with specific clinical phenotypes can help to assess sudden cardiac death risk and guide counseling around behavioral and environmental exposures that may worsen disease. Important expansions of the current genotype-phenotype profiling include the newly DCM-associated FLNC variant, prognostically significant LMNA, DSP inflammatory cardiomyopathy, and the highly penetrant features of RBM20 variants as well as the role of TTN variants in compounding the effects of environmental factors on toxin-mediated DCM. Future directions to improve diagnostic accuracy and prognostic improvement in DCM will center not just on identification of new genes, but also on understanding the interaction of known and novel variants in known DCM genes with patient genetic background and environment.

hESC derived cardiomyocyte biosensor to detect the different types of arrhythmogenic properties of drugs

In the present work, we introduce a new cell-based biosensor for detecting arrhythmias based on a novel utilization of the combination of the Atomic Force Microscope (AFM) lateral force measurement as a nanosensor with a dual 3D cardiomyocyte syncytium. Two spontaneously coupled clusters of cardiomyocytes form this. The syncytium's functional contraction behavior was assessed using video sequences analyzed with Musclemotion ImageJ/Fiji software, and immunocytochemistry evaluated phenotype composition. The application of caffeine solution induced arrhythmia as a model drug, and its spontaneous resolution was monitored by AFM lateral force recording and interpretation and calcium fluorescence imaging as a reference method describing non-synchronized contractions of cardiomyocytes. The phenotypic analysis revealed the syncytium as a functional contractile and conduction cardiac behavior model. Calcium fluorescence imaging was used to validate that AFM fully enabled to discriminate cardiac arrhythmias in this in vitro cellular model. The described novel 3D hESCs-based cellular biosensor is suitable to detect arrhythmic events on the level of cardiac contractile and conduction tissue cellular model. The resulting biosensor allows for screening of arrhythmogenic properties of tailored drugs enabling its use in precision medicine.

Acute Cardiac Emergencies

Acute cardiac emergencies are life threatening. The initial responses to acute cardiac emergencies must be rapid, efficient, skillful, and well-planned. The goal of this article is to provide information that can be used to facilitate the prompt recognition and treatment of the most common acute cardiac emergencies.

Temporal Changes in Beat-to-Beat Variability of Repolarization Predict Imminent Nonsustained Ventricular Tachycardia in Patients With Ischemic and Nonischemic Dilated Cardiomyopathy

Background

An increase in beat‐to‐beat variability of repolarization (BVR) predicts arrhythmia onset in experimental models, but its clinical translation is not well established. We investigated the temporal changes in BVR before nonsustained ventricular tachycardia (nsVT) in patients with implantable cardioverter defibrillator (ICD).

Methods and Results

Patients with nsVT on 24‐hour Holter before ICD implantation for ischemic cardiomyopathy (ischemic cardiomyopathy+nsVT, n=43) or dilated cardiomyopathy (dilated cardiomyopathy+nsVT, n=37), matched ICD candidates without nsVT (ischemic cardiomyopathy‐nsVT, n=29 and dilated cardiomyopathy‐nsVT, n=26), and patients without ICD without structural heart disease (n=50) were studied. Digital Holter recordings from these patients were analyzed using a modified fiducial segment averaging technique to detect the QT interval. The nsVT episodes were semi‐automatically identified and QT‐BVR was assessed 1‐, 5‐, and 30‐minutes before nsVT, and at rest (at 3:00 am). Resting BVR was higher in ICD patients compared with controls without structural heart disease. In ICD patients with nsVT, BVR increased significantly 1‐minute pre‐nsVT in ischemic cardiomyopathy (2.21±0.59 ms, versus 5 minutes pre‐nsVT: 1.78±0.50 ms, P<0.001) and dilated cardiomyopathy (2.09±0.57 ms, versus 5‐minutes pre‐nsVT: 1.58±0.51 ms, P<0.001), but not in patients without nsVT. In multivariable Cox regression analysis, pre‐nsVT BVR was a significant predictor for appropriate therapy during follow‐up.

Conclusions

Baseline BVR is elevated and temporal changes in BVR predict imminent nsVT events in patients with ICD independent of underlying cause. Real‐time BVR monitoring could be used to predict impending ventricular arrhythmia and allow preventive therapy to be incorporated into ICDs.

Stereotactic Radiotherapy: An Alternative Option for Refractory Ventricular Tachycardia to Drug and Ablation Therapy

Refractory ventricular tachycardia (VT) often occurs in the context of organic heart disease. It is associated with significantly high mortality and morbidity rates. Antiarrhythmic drugs and catheter ablation represent the two main treatment options for refractory VT, but their use can be associated with inadequate therapeutic responses and procedure-related complications. Stereotactic body radiotherapy (SBRT) is extensively applied in the precision treatment of solid tumors, with excellent therapeutic responses. Recently, this highly precise technology has been applied for radioablation of VT, and its early results demonstrate a favorable safety profile. This review presents the potential value of SBRT in refractory VT.

Process Mapping Strategies to Prevent Subcutaneous Implantable Cardioverter-Defibrillator Infections

BACKGROUND

Infection remains a major complication of cardiac implantable electronic devices (CIEDs) and can lead to significant morbidity and mortality. Implantable devices that avoid transvenous leads, such as the subcutaneous implantable cardioverter-defibrillator (S-ICD), can reduce the risk of serious infection-related complications, such as bloodstream infection and infective endocarditis. While the 2017 AHA/ACC/HRS guidelines include recommendations for S-ICD use for patients at high risk of infection, currently, there are no clinical trial data that address best practices for the prevention of S-ICD infections. Therefore, an expert panel was convened to develop consensus on these topics.

METHODS

An expert process mapping methodology was used to achieve consensus on the appropriate steps to minimize or prevent S-ICD infections. Two face-to-face meetings of high-volume S-ICD implanters and an infectious diseases specialist, with expertise on cardiovascular implantable electronic device infections, were conducted to develop consensus on useful strategies pre-, peri-, and post-implant to reduce S-ICD infection risk.

RESULTS

Expert panel consensus of recommended steps for patient preparation, S-ICD implantation, and post-operative management were developed to provide guidance in individual patient management.

CONCLUSION

Achieving expert panel consensus by process mapping methodology for S-ICD infection prevention was attainable, and the results should be helpful to clinicians in adopting interventions to minimize risks of S-ICD infection. This article is protected by copyright. All rights reserved.

Brugada pattern unmasked during COVID-19 infection -:A case report

The current pandemic caused by the coronavirus disease 2019 (COVID-19) continues affecting millions of people worldwide. Various cardiovascular manifestations have been associated with COVID-19 but only a few case reports of Brugada syndrome in acute respiratory syndrome by SARS-CoV-2 were published. The diagnosis, prognosis, and treatment remain a challenge and represent a concern in terms of management in this population. We describe a case of a 66-year-old patient with COVID-19 presenting a coved type-1 Brugada pattern in electrocardiogram. Drug challenge was performed for the diagnosis of Brugada syndrome and electrophysiological study for risk stratification. .

Pathogenicity Assignment of Variants in Genes Associated With Cardiac Channelopathies Evolve Toward Diagnostic Uncertainty

BACKGROUND

Accurately determining variant pathogenicity is critical in the diagnosis of cardiac channelopathies; however, it remains unknown how variant pathogenicity status changes over time. Our aim is to use a comprehensive analysis of ClinVar to understand the mutability of variant evaluation in channelopathy-associated genes to inform clinical decision-making around variant calling.

METHODS

We identified 10 genes (RYR2, CASQ2, KCNQ1, KCNH2, SCN5A, CACNA1C, CALM1, CALM2, CALM3, TRDN) strongly associated with cardiac channelopathies, as well as 3 comparison gene sets (disputed long QT syndrome, sudden unexpected death in epilepsy, and all ClinVar). We comprehensively analyzed variant pathogenicity calls over time using the ClinVar database with Rstudio. Analyses focused on the frequency and directionality of clinically meaningful changes in disease association, defined as a change from one of the following three categories to another: likely benign/benign, conflicting evidence of pathogenicity/variant of uncertain significance, and likely pathogenic/pathogenic.

RESULTS

In total, among channelopathy-associated genes, there were 9975 variants in ClinVar and 8.4% had a clinically meaningful change in disease association at least once over the past 10 years, as opposed to 4.9% of all ClinVar variants. The 3 channelopathy-associated genes with the most variants undergoing a clinically significant change were KCNQ1 (20.9%), SCN5A (11.2%), and KCNH2 (10.1%). Ten of the 12 included genes had variant evaluations that trended toward diagnostic uncertainty over time. Specifically, channelopathy-associated gene variants with either pathogenic/likely pathogenic or benign/likely benign assignments were 5.6× and 2×, respectively, as likely to be reevaluated to conflicting/variant of uncertain significance compared to the converse.

CONCLUSIONS

Over the past 10 years, 8.4% of variants in channelopathy-associated genes have changed pathogenicity status with a decline in overall diagnostic certainty. Ongoing clinical and genetic variant follow-up is needed to account for presence of clinically meaningful change in variant pathogenicity assignment over time.

Catheter Ablation for Ventricular Tachycardia in Ischaemic Versus Non-Ischaemic Cardiomyopathy: A Systematic Review and Meta-Analysis

BACKGROUND

There are differences in substrate and ablation approaches for ventricular tachycardia (VT) in ischaemic (ICM) and non-ischaemic cardiomyopathy (NICM).

OBJECTIVE

To perform a systematic review and meta-analysis comparing clinical and procedural characteristics/outcomes of VT ablation in ICM versus NICM.

METHODS

Electronic databases were searched for comparative studies reporting outcomes of VT ablation in patients with ICM and NICM. Primary outcomes were acute procedural success, VT recurrence and long-term mortality. Meta-analyses were performed using random-effects modelling.

RESULTS

Thirty-one (31) studies (7,473 patients; 4,418 ICM and 3,055 NICM) were included. Patients with ICM were significantly older (67.0 vs 55.3 yrs), more commonly male (89% vs 79%), had lower left ventricular ejection fraction (29% vs 38%) were less likely to undergo epicardial access (11% vs 36%) and were more likely to require haemodynamic support during ablation (relative risk [RR] 1.30; 95% CI 1.01-1.69). Acute procedural success (i.e. non-inducibility of VT) was higher in the ICM cohort (RR 1.10, 95% CI 1.05-1.15). Recurrence of VT at follow-up was significantly lower in the ICM cohort (RR 0.77; 95% CI 0.70-0.84). Peri-procedural mortality, incidence of procedural complications and long-term mortality were not significantly different between the cohorts.

CONCLUSIONS

NICM and ICM patients undergoing VT ablation are fundamentally different in their clinical characteristics, ablation approaches, acute procedural outcomes and likelihood of VA recurrence. VT ablation in NICM has a lower likelihood of procedural success with increased risk of VA recurrence, consistent with known challenging arrhythmia substrate.

Public knowledge and attitudes toward automated external defibrillators use among first aid eLearning course participants: a survey

Objective

Survival from out-of-hospital cardiac arrest (OHCA) often depends on the effective and immediate use of automated external defibrillators (AEDs). Given that there have been few studies about AED use in China, the purpose of this study is to investigate the knowledge and attitudes regarding AED use among the Chinese public, then provide an effective suggestion for AED education strategies and legislation.

Method

The online survey was conducted among Chinese participants of the First Aid eLearning courses in June 2020.

Result

A total of 2565 (95.00%) surveys were completed, only 23.46% of respondents with non-medical related respondents reported having attended previous AED training courses. Regarding the basic knowledge of AEDs, few respondents (12.28%, n = 315) could answer all four questions correctly. 95.67% (n = 2454) were willing to learn AED use. Even if without the precondition of being skilled in AEDs, the female was more likely to rescue OHCA patients than the male (p = 0.003). Almost all respondents (96.65%) showed a strong willingness to rescue OHCA patients with training in using AEDs. The top four barriers to rescuing OHCA patients were lack of practical performing ability (60.47%), fear of hurting patients (59.30%), inadequate knowledge of resuscitation techniques (44.19%), and worry about taking legal responsibility (26.74%).

Conclusion

Our study reflects a deficiency of AED knowledge among the general public in China. However, positive attitudes towards rescuing OHCA patients and learning AED use were observed, which indicates that measures need to be taken to disseminate knowledge and use of AEDs.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13019-022-01863-1.

Integrating clinical genetics in cardiology: Current practices and recommendations for education

PURPOSE

Recent advances in genetics can facilitate the identification of at-risk individuals and diagnosis of cardiovascular disorders. As a nascent field, more research is needed to optimize the clinical practice of cardiovascular genetics, including the assessment of educational needs to promote appropriate use of genetic testing.

METHODS

Qualitative interviews conducted with cardiovascular specialists (N = 43) were audiotaped. Thematic analysis was conducted on professional transcripts.

RESULTS

Participants recognized the value of genetics in identifying and diagnosing at-risk individuals. However, organizational systems, cost, and feeling of unpreparedness were identified as barriers. Participants felt that the rapid pace of genetic science resulted in further challenges to maintaining an adequate knowledge base and highlighted genetics experts' importance. Even when a genetics expert was available, participants wanted to know more about which patients benefit most from genetic testing and expressed a desire to better understand management recommendations associated with a positive test result.

CONCLUSION

Participants recognized the benefit but felt underprepared to provide recommendations for genetic testing and, in some cases, lacked organizational resources to refer patients to a genetics expert. Additional training in genetics for cardiology practitioners and ensuring availability of a genetics expert can improve the use of genetics in cardiology settings.

Drug Interactions Affecting Antiarrhythmic Drug Use

Antiarrhythmic drugs (AAD) play an important role in the management of arrhythmias. Drug interactions involving AAD are common in clinical practice. As AADs have a narrow therapeutic window, both pharmacokinetic as well as pharmacodynamic interactions involving AAD can result in serious adverse drug reactions ranging from arrhythmia recurrence, failure of device-based therapy, and heart failure, to death. Pharmacokinetic drug interactions frequently involve the inhibition of key metabolic pathways, resulting in accumulation of a substrate drug. Additionally, over the past 2 decades, the P-gp (permeability glycoprotein) has been increasingly cited as a significant source of drug interactions. Pharmacodynamic drug interactions involving AADs commonly involve additive QT prolongation. Amiodarone, quinidine, and dofetilide are AADs with numerous and clinically significant drug interactions. Recent studies have also demonstrated increased morbidity and mortality with the use of digoxin and other AAD which interact with P-gp. QT prolongation is an important pharmacodynamic interaction involving mainly Vaughan-Williams class III AAD as many commonly used drug classes, such as macrolide antibiotics, fluoroquinolone antibiotics, antipsychotics, and antiemetics prolong the QT interval. Whenever possible, serious drug-drug interactions involving AAD should be avoided. If unavoidable, patients will require closer monitoring and the concomitant use of interacting agents should be minimized. Increasing awareness of drug interactions among clinicians will significantly improve patient safety for patients with arrhythmias.

COVID-19 and Cardiac Arrhythmias: a Contemporary Review

Purpose of Review

A significant proportion of patients infected by the severe acute respiratory syndrome-coronavirus (SARS-CoV2) (COVID-19) also have disorders affecting the cardiac rhythm. In this review, we provide an in-depth review of the pathophysiological mechanisms underlying the associated arrhythmic complications of COVID-19 infection and provide pragmatic, evidence-based recommendations for the clinical management of these conditions.

Recent Findings

Arrhythmic manifestations of COVID-19 include atrial arrhythmias such as atrial fibrillation or atrial flutter, sinus node dysfunction, atrioventricular conduction abnormalities, ventricular tachyarrhythmias, sudden cardiac arrest, and cardiovascular dysautonomias including the so-called long COVID syndrome. Various pathophysiological mechanisms have been implicated, such as direct viral invasion, hypoxemia, local and systemic inflammation, changes in ion channel physiology, immune activation, and autonomic dysregulation. The development of atrial or ventricular arrhythmias in hospitalized COVID-19 patients has been shown to portend a higher risk of in-hospital death.

Summary

Arrhythmic complications from acute COVID-19 infection are commonly encountered in clinical practice, and COVID-19 patients with cardiac complications tend to have worse clinical outcomes than those without. Management of these arrhythmias should be based on published evidence-based guidelines, with special consideration of the acuity of COVID-19 infection, concomitant use of antimicrobial and anti-inflammatory drugs, and the transient nature of some rhythm disorders. Some manifestations, such as the long COVID syndrome, may lead to residual symptoms several months after acute infection. As the pandemic evolves with the discovery of new SARS-CoV2 variants, development and use of newer anti-viral and immuno-modulator drugs, and the increasing adoption of vaccination, clinicians must remain vigilant for other arrhythmic manifestations that may occur in association with this novel but potentially deadly disease.

Sudden Death and Cardiac Arrythmia With Lamotrigine: A Rapid Systematic Review

BACKGROUND AND OBJECTIVES

A recent Food and Drug Administration warning concerning an arrhythmogenic potential of lamotrigine created concern in the neurologic community. This warning was based on in vitro studies, but no clinically relevant risk was considered. This rapid systematic review aims to elucidate the risk of lamotrigine on sudden death or ECG abnormalities.

METHODS

We conducted a systematic search of Ovid Medline and Ovid Embase, including randomized controlled trials and observational studies and studies of people with or without epilepsy, with the outcome measures sudden unexpected death in epilepsy (SUDEP) or sudden cardiac death as well as the development or worsening of ECG abnormalities. We evaluated the sudden death definitions used in all included studies, as some could have used unclear or overlapping definitions. We used the American Academy of Neurology risk of bias tool to evaluate the class of evidence and the GRADE approach to evaluate our confidence in the evidence.

RESULTS

We included 26 studies with 24,962 participants, of whom 2,326 used lamotrigine. Twelve studies showed no significant risk of SUDEP for lamotrigine users. One study reporting on sudden cardiac death and 3 studies with unclear sudden death definitions did not report an elevated risk of death in lamotrigine users compared to controls. In 10 studies reporting on ECG measures, there was no statistically significant increased risk among lamotrigine users except in 2 studies. These 2 studies reported either "slight increases" in PR interval or an increased PQ interval that the primary study authors believed to be related to structural cardiac differences rather than an effect of lamotrigine. One study was rated Class II; all others were Class III or IV. We had very low confidence in the evidence following the GRADE assessment. None of the studies examined the risk of lamotrigine in people with preexisting cardiac conditions.

DISCUSSION

There is insufficient evidence to support or refute that lamotrigine is associated with sudden death or ECG changes in people with or without epilepsy as compared to antiseizure medication or placebo, due to the high risk of bias in most studies and low precision and inconsistency in the reported results.

Combined Use of S-ICD and Absorbable Antibacterial Envelopes: A Proof-of-concept Study

BACKGROUND

Absorbable antibacterial envelopes (AAEs) are currently recommended in patients undergoing a transvenous ICD implantation in cases at high risk of infection, who are now preferably implanted with a subcutaneous ICD (S-ICD). Nevertheless, experiences using a combined approach with S-ICD and AAE have not been reported. The aim of our study was to evaluate this strategy in patients at very high risk of infection.

METHODS

Twenty-five patients were implanted with the S-ICD+AAE using our combined approach, restricted to patients who would fit our decisional flow algorithm identifying very high-risk patients. Patients were followed up 1 month after discharge and every 6 months thereafter. Complications were defined as device-related events requiring medical or surgical intervention for resolution and/or device reprogramming.

RESULTS

Twenty-five patients (92% males, mean age 58.5±14.1 years) were implanted with the S-ICD device and the AAE using our combined approach. The most common high-infective risk factors were diabetes requiring insulin treatment (80%) and CKD requiring hemodialysis (48%), with 7 (28%) patients presenting with more than 2 risk factors. A single mild early post-operative hematoma was observed that was managed conservatively with a spontaneous resolution. Despite a very high-risk cohort, only a single late pocket infection was detected and solved conservatively with antibiotic therapy.

CONCLUSIONS

The preliminary data of this proof-of-concept study show how a combined deployment of AAE and S-ICD in selected patients at very high risk of infection is a safe and feasible technique and may offer a reliable treatment option in specific and selected clinical settings.

Radiosurgery in Treatment of Ventricular Tachycardia – Initial Experience Within the Polish SMART-VT Trial

Background

Stereotactic Arrhythmia Radioablation (STAR) is an emerging treatment modality for patients with sustained ventricular tachycardia (VT) and refractory to treatment with drugs and radiofrequency catheter ablation (RFA). It is believed that up to 12–17% of patients experience recurrence of VT within 1 year of follow-up; thus, novel therapeutic options are needed. The aim of this article is to present initial experience within a novel treatment modality for VT.

Case Summary

Two patients with a medical history of coronary artery disease and heart failure with reduced left ventricle (LV) ejection fraction, after implantation of cardioverter-defibrillator (ICD) and previous unsuccessful RFAs owing to sustained VT were admitted to the cardiology department due to recurrence of sustained VT episodes. With electroanatomical mapping (EAM), the VT substrate in LV has been confirmed and specified. In order to determine the target volume for radioablation, contrast-enhanced computed tomography was performed and the arrhythmia substrate was contoured using EAM data. Using the Volumetric Modulated Arc Therapy technique and three 6 MeV flattening filter-free photon beam fields, a single dose of 25 Gy was delivered to the target volume structure located in the apex and anterior apical segments of LV in the first patient and in the apex, anterolateral and inferior apical segments of the second patient. In both cases, volumes of the target structures were comparable. Interrogation of the implanted ICD at follow-up visits throughout 6 months after the treatment revealed no VT episodes in the first patient and sudden periprocedural increase in VT burden with a subsequent gradual decrease of ventricular arrhythmia to only two non-sustained episodes at the end of the follow-up period in case of the second patient. A significant reduction in premature ventricular contractions burden was observed compared to the pre-treatment period. No noticeable deterioration in LV function was noted, nor any adverse effects of radiosurgery associated with the implanted device.

Conclusion

The early response to STAR can be unpredictable and probably does not reflect the final outcome of irradiation. Close monitoring of patients, especially in the early period after irradiation is crucial to properly handle potentially harmful early reactions to STAR.

Compassionate Use of Yuanjiang Decoction, a Traditional Chinese Medicinal Prescription, for Symptomatic Bradyarrhythmia

Background: No effective medication is available for symptomatic bradyarrhythmia, particularly in low socioeconomic status (SES) population.

Objective: To explore the safety and efficacy of Yuanjiang decoction, a traditional Chinese medicinal prescription, for symptomatic bradyarrhythmia on a compassionate-use basis.

Methods: This compassionate-use study was conducted in Beijing, China between January 2019 and January 2020. Eligible participants were recruited and treated with Yuanjiang decoction (composed of 6 Chinese herbal medicines), 200 ml twice daily for 16 weeks. Analyses were done with the intention-to-treat (ITT) approach. The primary outcome measure was the proportion of participants who achieved a favorable treatment outcome at 16 weeks.

Results: As of January 2020, 184 patients were included. After 16-weeks treatment, 12 participants were lost to contact while 21 participants were terminated from this study, with a drop-out rate of 17.93%. The most common treatment-related adverse events were xerostomia (6.52%), constipation (6.45%) and sleepiness (3.26%). The proportion of participants with favorable treatment outcome was 65.22% at 4 weeks, 59.78% at 8 weeks (OR: 1.11, 95% CI: 0.71–1.73), 61.41% at 12 weeks (OR: 1.16, 95% CI: 0.92–1.45) and 60.87% at 16 weeks (OR: 1.15, 95% CI: 0.98–1.35). In the multifactor regression analysis, the favorable treatment outcome at 16 weeks was significantly associated with completing at least 8 weeks treatment (OR: 2.053, 95% CI: 1.064–3.560), while unfavorable treatment outcome was significantly associated with an atrioventricular block (OR: 0.255, 95% CI: 0.083–0.784), current smoking (OR: 0.343, 95% CI: 0.027–0.487), and syncope in the month before treatment (OR: 0.321, 95%CI: 0.114–0.904).

Conclusion: This compassionate-use study showed encouraging outcomes of treatment with Yuanjiang decoction, without serious adverse events. This study identified several key factors that may affect outcomes. These findings helped inform the design and assess the feasibility of a large-scale randomized clinical trial.

KCNH2 p.Gly262AlafsTer98: A New Threatening Variant Associated with Long QT Syndrome in a Spanish Cohort

Long QT syndrome (LQTS) is an inherited (autosomal dominant) channelopathy associated with susceptibility to ventricular arrhythmias due to malfunction of ion channels in cardiomyocytes, that could lead to sudden death (SD). Most pathogenic variants are in the main 3 genes: KCNQ1 (LQT1), KCNH2 (LQT2) and SCN5A (LQT3). Efforts to improve the understanding of the genotype-phenotype relationship are essential to improve the medical clinical practice. In this study, we identified all index patients referred for NGS genetic sequencing due to LQTS, in a Spanish cohort, who were carriers of a new pathogenic variant (KCNH2 p.Gly262AlafsTer98). Genetic and clinical family screening was performed in order to describe its phenotypic characteristics. We identified 22 relatives of Romani ethnicity, who were carriers of the variant. Penetrance reached a 100% and adherence to medical treatment was low. There was a high rate of clinical events, particularly arrhythmic events and SD (1 in every 4 patients presented syncope, 1 presented an aborted SD, 2 obligated carriers suffered SD before the age of 40 and 4 out of 6 carriers of an implantable cardioverter-defibrillator (ICD) had appropriate ICD therapies. Correct adherence to medical treatment in all carriers should be specially encouraged in this population. ICD implantation decision in non-compliant patients, and refusing left cardiac sympathetic denervation, should be carefully outweighed.

Reliability of pediatric ventricular function analysis by short-axis "single-cycle-stack-advance" single-shot compressed-sensing cines in minimal breath-hold time

OBJECTIVES

Cardiovascular magnetic resonance (CMR) cine imaging by compressed sensing (CS) is promising for patients unable to tolerate long breath-holding. However, the need for a steady-state free-precession (SSFP) preparation cardiac cycle for each slice extends the breath-hold duration (e.g. for 10 slices, 20 cardiac cycles) to an impractical length. We investigated a method reducing breath-hold duration by half and assessed its reliability for biventricular volume analysis in a pediatric population.

METHODS

Fifty-five consecutive pediatric patients (median age 12 years, range 7-17) referred for assessment of congenital heart disease or cardiomyopathy were included. Conventional multiple breath-hold SSFP short-axis (SAX) stack cines served as the reference. Real-time CS SSFP cines were applied without the steady-state preparation cycle preceding each SAX cine slice, accepting the limitation of omitting late diastole. The total acquisition time was 1 RR interval/slice. Volumetric analysis was performed for conventional and "single-cycle-stack-advance" (SCSA) cine stacks.

RESULTS

Bland-Altman analyses [bias (limits of agreement)] showed good agreement in left ventricular (LV) end-diastolic volume (EDV) [3.6 mL (- 5.8, 12.9)], LV end-systolic volume (ESV) [1.3 mL (- 6.0, 8.6)], LV ejection fraction (EF) [0.1% (- 4.9, 5.1)], right ventricular (RV) EDV [3.5 mL (- 3.34, 10.0)], RV ESV [- 0.23 mL (- 7.4, 6.9)], and RV EF [1.70%, (- 3.7, 7.1)] with a trend toward underestimating LV and RV EDVs with the SCSA method. Image quality was comparable for both methods (p = 0.37).

CONCLUSIONS

LV and RV volumetric parameters agreed well between the SCSA and the conventional sequences. The SCSA method halves the breath-hold duration of the commercially available CS sequence and is a reliable alternative for volumetric analysis in a pediatric population.

KEY POINTS

• Compressed sensing is a promising accelerated cardiovascular magnetic resonance imaging technique. • We omitted the steady-state preparation cardiac cycle preceding each cine slice in compressed sensing and achieved an acquisition speed of 1 RR interval/slice. • This modification called "single-cycle-stack-advance" enabled the acquisition of an entire short-axis cine stack in a single short breath hold. • When tested in a pediatric patient group, the left and right ventricular volumetric parameters agreed well between the "single-cycle-stack-advance" and the conventional sequences.

Rate dependence of early afterdepolarizations in the His-Purkinje system: A simulation study

BACKGROUND AND OBJECTIVE

Early afterdepolarizations (EADs) are associated with a variety of arrhythmias and have the property of rate dependence. EADs can occur in Purkinje cells while the effect of rate dependence of EADs in the His-Purkinje system has not been fully investigated. In order to reveal the rate dependence of EADs in the His-Purkinje system and its effect on ventricular electrical activities, the simulation research was carried out in this manuscript.

METHODS

This manuscript first studied the relationship between the occurrence of EADs and stimulation cycle length on the DiFranNoble cell model. Then, the relationship between the rate dependence of EADs and the conduction block of the His-Purkinje system at slow heart rates was studied on the rabbit whole ventricular model including the His-Purkinje system, and its mechanism was analyzed from multiple angles.

RESULTS

① The rate dependence of EADs is related to the inconsistency of EADs occurrence in the His-Purkinje system. When the stimulation cycle length is long or short enough, EADs either occur or not occur stably in the His-Purkinje system, while in a certain stimulation cycle length window, the chaotic state of EADs will be observed. ② The key subcellular factors x-gate is an important mechanism involved to the rate dependence of EADs in the His-Purkinje system. ③ The discrete distribution of x-gate values and the "source-sink" mechanism lead to the inconsistency of EADs in the His-Purkinje system. The prolonged action potential duration caused by EADs can lead to conduction block at slow heart rates.

CONCLUSION

The rate dependence of EADs in Purkinje system can lead to disordered ventricular electrical activity.

S-ICDs: advantages and opportunities for improvement

INTRODUCTION

The subcutaneous implantable cardioverter defibrillator (S-ICD) is currently in its third generation and has been adopted in guidelines and in mainstream clinical practice. Considerable improvements have been made since the introduction of this device over a decade ago.

AREAS COVERED

A literature search was undertaken in Pubmed on articles relating to the S-ICD.

EXPERT OPINION

The therapy has been proven to be safe and effective and is a valuable option in selected patients. Nevertheless, there remain many shortcomings of the S-ICD which are discussed in this review, and which hopefully will be addressed by future generations of the device.

Rare case of Torsades de Pointes in severe hypothyroidism: literature review and challenges in management

Background

Hypothyroidism can manifest as several important cardiac abnormalities. There are few reports of ventricular dysrhythmias (VDs) in hypothyroidism. We described a rare case of VDs in severe hypothyroidism and reviewed the literature behind its management.

Case presentation

A 67-year-old gentleman, with poor compliance to treatment for Hashimoto’s thyroiditis, presented with palpitations to the Emergency Department. He had runs of non-sustained ventricular tachycardia (NSVT). He was treated with intravenous (IV) amiodarone and admitted to the intensive care unit for observation. He then developed recurrent Torsades de Pointes (Tdp) despite treatment with several anti-arhythmics. He required electrical cardioversion and eventual transvenous overdrive pacing (OP). VT recurred while he was on OP. VT resolved and he was weaned off OP only after adequate thyroid hormone replacement.

Conclusions

VDs, including NSVT, Tdp, and VT, are rare and potentially lethal in hypothyroidism. Our case demonstrates important challenges in the management of severe hypothyroidism. Here, VDs are often refractory to treatment with drugs and electrical means. The choice(s) of anti-arrhthymics requires careful consideration and can be difficult before thyroid function tests are known. Amiodarone use should be cautioned as it is associated with thyroid dysfunction and QT interval prolongation.

There is no literature to guide thyroid hormone replacement in this disease. Aggressive replacement is associated with adverse cardiovascular effects. Our case showed a fine balance between the risk of rapid thyroid hormone replacement and the urgency to terminate VDs. Its administration should be carefully monitored amidst bridging strategies like electrical cardioversion and OP to manage life-threatening VDs.

DREAM-ICD-II Study

BACKGROUND

Regulatory authorities of most industrialized countries recommend 6 months of private driving restriction after implantation of a secondary prevention implantable cardioverter-defibrillator (ICD). These driving restrictions result in significant inconvenience and social implications. This study aimed to assess the incidence rate of appropriate device therapies in contemporary recipients of a secondary prevention ICD.

METHODS

This retrospective study at 3 Canadian tertiary care centers enrolled consecutive patients with new secondary prevention ICD implants between 2016 and 2020.

RESULTS

For a median of 760 days (324, 1190 days), 721 patients were followed up. The risk of recurrent ventricular arrhythmia was highest during the first 3 months after device insertion (34.4%) and decreased over time (10.6% between 3 and 6 months, 11.7% between 6 and 12 months). The corresponding incidence rate per 100 patient-days was 0.48 (95% CI, 0.35-0.64) at 90 days, 0.28 (95% CI, 0.17-0.45) at 180 days, and 0.21 (95% CI, 0.13-0.33) between 181 and 365 days after ICD insertion (P<0.001). The cumulative incidence of arrhythmic syncope resulting in sudden cardiac incapacitation was 1.8% within the first 90 days and subsequently dropped to 0.4% between 91 and 180 days (P<0.001) after ICD insertion.

CONCLUSIONS

The incidence rate of appropriate therapies resulting in sudden cardiac incapacitation in contemporary recipients of a secondary prevention ICD is much lower than previously reported and declines significantly after the first 3 months. Lowering driving restrictions to 3 months after the index cardiac event seems safe, and revision of existing guidelines should be considered in countries still adhering to a 6-month period. Existing restrictions for private driving after implantation of a secondary prevention ICD should be reconsidered.

Economic Issues in Heart Failure in the United States

The cost of heart failure care is high owing to the cost of hospitalization and chronic treatments. Heart failure treatments vary in their benefit and cost. The cost effectiveness of therapies can be determined by comparing the cost of treatment required to obtain a certain benefit, often defined as an increase in 1 year of life. This review was sponsored by the Heart Failure Society of America and describes the growing economic burden of heart failure for patients and the health care system in the United States. It also provides a summary of the cost effectiveness of drugs, devices, diagnostic tests, hospital care, and transitions of care for patients with heart failure. Many medications that are no longer under patent are inexpensive and highly cost-effective. These include angiotensin-converting enzyme inhibitors, beta-blockers and mineralocorticoid receptor antagonists. In contrast, more recently developed medications and devices, vary in cost effectiveness, and often have high out-of-pocket costs for patients.

Delayed intrinsicoid deflection: Electrocardiographic harbinger of heart disease

Delayed intrinsicoid deflection (DID) is an emerging electrocardiogram (ECG) marker of major clinical significance that is increasingly getting attention. Intrinsicoid deflection measures ventricular depolarization in the initial portion of the QRS complex, and DID is defined as an R wave peak time of ≥50 ms in leads V₅ and V₆ . Prior studies have identified an independent association between DID and cardiovascular conditions such as left ventricular hypertrophy, heart failure, and sudden cardiac death. The exact mechanism that results in DID remains unknown. Animal models indicate that DID may result from abnormal calcium and potassium conductance as well as extracellular matrix remodeling. DID remains an ECG marker of interest given its potential predictive value of underlying cardiovascular pathology and adverse events. This review provides an update on the proposed mechanisms and associations, as well as the clinical and research implications of DID.

A Wearable Cardioverter Defibrillator with a Low False Alarm Rate

BACKGROUND

A wearable cardioverter defibrillator (WCD) is indicated in appropriate patients to reduce risk for sudden cardiac death. Challenges for patients wearing a WCD have been frequent false shock alarms primarily due to ECG noise and wear discomfort.

OBJECTIVE

To test a contemporary WCD designed for reduced false shock alarms and improved comfort.

METHODS

130 patients with LVEF ≤ 40% and an active implantable cardioverter defibrillator (ICD) were fitted with the ASSURE WCD (Kestra Medical Technologies) and followed 30 days. WCD detection was enabled and shock alarm markers recorded, but shocks and shock alarms disabled. All WCD episodes and ICD VT/VF episodes were adjudicated. The primary endpoint was the false positive shock alarm rate with a performance goal of 1 every 3.4 days (0.29 per patient-day).

RESULTS

Of 163 WCD episodes, 4 were VT/VF and 159 non-VT/VF (121 rhythms with noise, 32 uncertain with noise, 6 atrial flutter without noise). Only 3 false positive shock alarm markers were recorded; 1 false positive shock alarm every 1,333 patient-days (0.00075 per patient-day, 95% CI: 0.00015-0.00361; p < 0.001). No ICD recorded VT/VF episodes meeting WCD detection criteria (≥ 170 bpm for ≥ 20 seconds) were missed by the WCD during 3,501 patient-days of use. Median wear was 31.0 days (IQR 2.0) and median daily use 23.0 hours (IQR 1.7). Adverse events were mostly mild: skin irritation (19.4%) and musculoskeletal discomfort (8.5%).

CONCLUSION

The ASSURE WCD demonstrated a low false positive shock alarm rate, low patient-reported discomfort, and no serious adverse events. This article is protected by copyright. All rights reserved.

Workup for Suspected Brugada Syndrome: Two Case Reports for the General Practitioner

While a large proportion of ST-segment elevation on EKG is related to myocardial ischemia, the differential diagnosis must include pericarditis, channelopathies, and various genetic conditions. Identifying and working up such abnormalities present a challenge to primary care providers (PCPs). We present two clinical cases of young male patients with ST-segment elevation in anteroseptal leads suspicious for Brugada syndrome and show how to risk stratify and manage them.

Our first case presents a 23-year-old male with no past medical history with acute onset substernal chest pain, shortness of breath, and palpitations. Initial workup revealed negative serial troponins and normal B-type natriuretic peptide (BNP). The EKG revealed ST elevation in lead V2. An evaluation for Brugada syndrome was pursued. Upon completion of a procainamide challenge, it was determined that he did not have Brugada syndrome and was shortly discharged.

Our second case presents a 33-year-old male with no pertinent cardiac medical history who presented to an outpatient cardiology clinic after discovering an incidental ST elevation in V2 on EKG. His family history was negative for early atherosclerotic cardiovascular events or sudden cardiac death. The patient’s initial workup was negative. Suspicion for Brugada syndrome leads to performing a procainamide challenge, which was significant for ST changes in the anterolateral leads. He was asymptomatic during the challenge and initial presentation, and no further intervention was indicated. He was advised to avoid sodium channel blocking medications and treat any fevers and was sent for genetic testing.

These cases illustrate the importance of maintaining an appropriate suspicion for Brugada syndrome in young patients with minimal ischemic risk factors. We discuss a guideline-directed algorithmic workup for PCPs in suspicious individuals. Stratifying patients based on the presence of symptoms, history of tachyarrhythmias, and EKG findings before and after drug challenge allows physicians to guide further management of these patients.

Telemedicine in Cardiology: Modern Technologies to Improve Cardiovascular Patients’ Outcomes—A Narrative Review

The registration of physical signals has long been an important part of cardiological diagnostics. Current technology makes it possible to send large amounts of data to remote locations. Solutions that enable diagnosis and treatment without direct contact with patients are of enormous value, especially during the COVID-19 outbreak, as the elderly require special protection. The most important examples of telemonitoring in cardiology include the use of implanted devices such as pacemakers and defibrillators, as well as wearable sensors and data processing units. The arrythmia detection and monitoring patients with heart failure are the best studied in the clinical setting, although in many instances we still lack clear evidence of benefits of remote approaches vs. standard care. Monitoring for ischemia is less well studied. It is clear however that the economic and organizational gains of telemonitoring for healthcare systems are substantial. Both patients and healthcare professionals have expressed an enormous demand for the further development of such technologies. In addition to these subjects, in this paper we also describe the safety concerns associated with transmitting and storing potentially sensitive personal data.

Epsilon Wave Masked by ST-Segment Elevation After Cardioversion From Sustained Ventricular Tachycardia: An Exceptional Manifestation of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy

BACKGROUND

Early recognition and management of ventricular dysrhythmia (VD) are among the top priorities in the medical field, and are very important in cases of suspected acute coronary syndrome (ACS). Here we present a case of ventricular tachycardia (VT), which should be considered in ACS.

CASE REPORT

A 59-year-old man with unstable vital signs visited the emergency department (ED) after a syncopal episode associated with chest discomfort. Initial electrocardiography (ECG) revealed wide complex tachycardia, which was considered monomorphic VT. After successful cardioversion, ST-segment elevation was observed on subsequent ECG with reciprocal ST-segment depression. Immediate pharmacological treatment and coronary angiography were performed because of suspected acute myocardial infarction; however, normal coronary arteries were observed. On subsequent ECG analysis, a small blip at the end of the QRS complex termed an epsilon wave, which is a characteristic finding in arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C), was detected in the V1 lead. A borderline diagnosis of ARVD/C was made based solely on ECG findings, and the definite diagnosis was confirmed using echocardiography. An implantable cardioverter-defibrillator was inserted soon after, and the patient reported no further events. Why Should an Emergency Physician be Aware of This?: ARVD/C is a critical disease entity that is commonly associated with life-threatening VA. However, presentations of ARVD/C resembling ACS are exceptionally rare. Accordingly, accurate diagnosis of ARVD/C in ED settings is clinically challenging. A high clinical suspicion is required to identify ARVD/C and avoid further life-threatening episodes.

Beta blockers for the treatment of arrhythmias: Bisoprolol - a systematic review

OBJECTIVES

Beta blockers have long been successfully used for the treatment of both supraventricular and ventricular arrhythmias. However, differences exist between their chemical structure, pharmacokinetic and pharmacodynamic properties (absorption, bioavailability, metabolism, hydrophilic or lipophilic character, selective or non-selective nature, the presence or absence of intrinsic sympathomimetic activity), which may confer different antiarrhythmic properties to different beta blockers. The aim of this study was to analyze the current existing evidence for bisoprolol for the treatment of both supraventricular and ventricular arrhythmias.

MATERIAL AND METHODS

Using the keywords "bisoprolol" and "arrhythmias" or "atrial fibrillation" or "ventricular tachycardia" or "premature ventricular complexes" or "ventricular fibrillation", the Medline database was searched for articles in English or French until April 2020 assessing the role of bisoprolol in the treatment of arrhythmias. Data was then analyzed according to the type of arrhythmia treated and the quality of evidence using the GRADE approach.

RESULTS

A total of 325 studies were identified, of which 28 were considered relevant to the current topic. Among these studies, 19 assessed the role of bisoprolol for the treatment of supraventricular arrhythmias, 8 its role in treating ventricular arrhythmias and 1 its role in supraventricular and ventricular arrhythmias. The quality of evidence varied from low (7 studies) to high (5 studies).

CONCLUSION

Current evidence exists supporting the use of bisoprolol for the treatment of supraventricular arrhythmias, especially for rate control during atrial fibrillation. Evidence also exists for its efficacy in the treatment of ventricular arrhythmias, both in primary and in secondary prevention.