Electrical storm: definitions, clinical importance, and treatment

New Diseases Related to Cardiac Implantable Electronic Devices (CIEDs): An Overview

The widespread use of Cardiac Implantable Electronic Devices (CIEDs) has transformed the management of cardiac arrhythmias, improving survival and quality of life for millions. However, this progress has introduced a range of device-related complications, which can significantly impact patient outcomes. This review examines "new diseases" linked to CIEDs, categorizing them into physical (e.g., infections, venous obstruction, lead failure, and device recalls) and functional complications (e.g., arrhythmias, pacemaker syndrome, and left ventricular dysfunction). Prevention and management strategies are emphasized. Emerging technologies, such as leadless devices, quadripolar leads, and remote monitoring systems, hold promise in reducing risks and enhancing patient care. Future directions include integrating artificial intelligence for real-time monitoring, improving device durability, and exploring novel materials to minimize infections and mechanical failures. Understanding CIED-related complications is essential for healthcare providers to balance the benefits and risks of these life-saving technologies.

A Case Report of Mycoplasma pneumoniae-induced fulminant myocarditis in a 15-year-old male leading to cardiogenic shock and electrical storm

Mycoplasma pneumoniae (M. pneumoniae) is a well-recognized pathogen primarily associated with respiratory tract infections. However, in rare instances, it can lead to extrapulmonary manifestations, including myocarditis. We present a case of a 15-year-old male who developed fulminant myocarditis, cardiogenic shock, and cardiac electrical storm attributed to M. pneumoniae infection. He underwent a combination of intra-aortic balloon pump (IABP) and veno-arterial extracorporeal membrane oxygenation (VA-ECMO) for cardiac support, ultimately surviving despite the intracardiac thrombus formation and embolic stroke. Following comprehensive treatment and rehabilitation, he was discharged in stable condition. This case underscores the importance of considering atypical pathogens as potential etiological factors in patients presenting with cardiac complications, especially in the adolescents. It also emphasizes the need for clinical vigilance and effective support for potential cardiac complications arising from M. pneumoniae infection.

Can stellate ganglion blockage be an alternative treatment for refractory ventricular arrhythmias: Case series

INTRODUCTION

Ventricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions which increase in frequency over the years. Electrical storm (ES) is defined as the occurrence of 3 or more continuous ventricular arrhythmia. The sympathetic nervous system has an important role in Ventricular arrythmias (VA) and is the target of treatment. Studies show that stellate ganglion blockade (SGB) can reduce cardiac sympathetic tone and is an alternative bridge therapy in VAs.

PATIENT CONCERNS

Among the patients who were admitted to the hospital with the complaints of general condition disorder and palpitation.

DIAGNOSIS

Patients were referred to the Cardiology department and diagnosed VA and ES. Patients who applied to the Cardiology Department with the diagnosis of VA or ES and did not benefit from antiarrhythmic drug therapy were selected and evaluated by a team of 2 anesthesiologists (cardiothoracic and pain specialists) and 2 cardiologists (1 of whom is an electrophysiology specialist).

INTERVENTION

In our study, ultrasound (USG) guided left SGB was applied to 10 VA and ES patients with implantable cardiac defibrillator (ICD). The 6-month results of the patients were evaluated retrospectively. For blockage, the solution was prepared by adding 8 mg dexamethasone, 40 mg lidocaine and 10 mg bupivacaine to 10 mL with physiological saline. The success of the procedure was evaluated with the development of Horner syndrome in the left eye.

OUTCOMES

Resistant VA developed in 2 of 10 patients who had left SGB due to VF/VT ES and were excluded from the study. One (1) month after the procedure it was seen that there was a statistically significant decrease in the number of shocks in 8 patients in the 6th month controls compared to the pre-procedure. The number of VES in the 1st and 6th months of the patients was also statistically significantly decreased compared to the pre-SSD (P = .01, P = .01, P = .01, respectively).

CONCLUSION

Unilateral USG-guided SGB application is an effective and safe method in patients with ES and VA. Long-term results can be satisfactory in successful responders in whom SGB is performed with a combination of local anesthetic and steroid.

Electrical storm in a middle-aged man

Electrical storm (ES) refers to a life-threatening condition characterised by three or more episodes of ventricular tachycardia (VT), ventricular fibrillation (VF), or appropriate implantable cardioverter defibrillator (ICD) shocks in 24 hours. We report a case of a 58-year-old man who suffered recurrent episodes of sustained VT despite appropriate defibrillation and antiarrhythmic drug therapy. On stepwise evaluation, arrhythmogenic right ventricular cardiomyopathy (ARVC) was considered the most likely substrate for his dysrhythmia. He was managed conservatively on antiarrhythmic drugs with no further clinical episodes of VT, and ICD implantation for secondary prophylaxis was recommended.

Funding

None declared.

Emergency Management of Electrical Storm: A Practical Overview

Electrical storm is a medical emergency characterized by ventricular arrythmia recurrence that can lead to hemodynamic instability. The incidence of this clinical condition is rising, mainly in implantable cardioverter defibrillator patients, and its prognosis is often poor. Early acknowledgment, management and treatment have a key role in reducing mortality in the acute phase and improving the quality of life of these patients. In an emergency setting, several measures can be employed. Anti-arrhythmic drugs, based on the underlying disease, are often the first step to control the arrhythmic burden; besides that, new therapeutic strategies have been developed with high efficacy, such as deep sedation, early catheter ablation, neuraxial modulation and mechanical hemodynamic support. The aim of this review is to provide practical indications for the management of electrical storm in acute settings.

What acute cardiac care physicians need to know from the latest 2022 ESC Guidelines for ventricular tachycardia and sudden cardiac death

The present paper summarizes and comments on the latest 2022 ESC guidelines on ventricular tachycardia and sudden cardiac death. Most relevant recommendations for acute cardiovascular care physicians are addressed, particularly, in the fields of coronary artery disease, dilated cardiomyopathy, and inflammatory diseases. New recommendations encompass the implantation of a defibrillator (ICD) in the setting of acute myocarditis. Furthermore, the pathophysiology of the electrical storm including involved molecular pathways as well as the angry Purkinje fibre syndrome is presented and discussed.

The first case series analysis on efficacy of esmolol injection for in-hospital cardiac arrest patients with refractory shockable rhythms in China

Background: This study assessed the effects of esmolol injection in patients with in-hospital cardiac arrest (IHCA) with refractory ventricular fibrillation (VF)/pulseless ventricular tachycardia (pVT).

Methods: From January 2018 to December 2021, 29 patients with IHCA with refractory shockable rhythm were retrospectively reviewed. Esmolol was administered after advanced cardiovascular life support (ACLS)-directed procedures, and outcomes were assessed.

Results: Among the 29 cases, the rates of sustained return of spontaneous circulation (ROSC), 24-h ROSC, and 72-h ROSC were 79%, 62%, and 59%, respectively. Of those patients, 59% ultimately survived to discharge. Four patients with cardiac insufficiency died. The duration from CA to esmolol infusion was significantly shorter for patients in the survival group (SG) than for patients in the dead group (DG) (12 min, IQR: 8.5–19.5 vs. 23.5 min, IQR: 14.4–27 min; p = 0.013). Of those patients, 76% (22 of 29) started esmolol administration after the second dose of amiodarone. No significant difference was observed in the survival rate between this group and groups administered an esmolol bolus simultaneously or before the second dose of amiodarone (43% vs. 64%, p = 0.403). Of those patients, 31% (9 of 29) were administered an esmolol bolus for defibrillation attempts ≤ 5, while the remaining 69% of patients received an esmolol injection after the fifth defibrillation attempt. No significant differences were observed in the rates of ≥ 24-h ROSC (67% vs. 60%, p = 0.73), ≥ 72-h ROSC (67% vs. 55%, p = 0.56), and survival to hospital discharge (67% vs. 55%, p = 0.56) between the groups administered an esmolol bolus for defibrillation attempts ≤ 5 and defibrillation attempts > 5.

Conclusion: IHCA patients with refractory shockable rhythms receiving esmolol bolus exhibited a high chance of sustained ROSC and survival to hospital discharge. Patients with end-stage heart failure tended to have attenuated benefits from beta-blockers. Further large-scale, prospective studies are necessary to determine the effects of esmolol in patients with IHCA with refractory shockable rhythms.

The imperfect storm: An uncommon presentation of Chagas disease

Electrical storm is defined as three or more sustained episodes of ventricular tachycardia, ventricular fibrillation, or appropriate cardioverter-defibrillator shocks during a 24-h period. These patients are notoriously difficult to manage. We present a case secondary to Chagas disease that was responsive to lidocaine. Although an uncommon presentation, given the large-scale population movement from South America, Chagas has an increased incidence and is an important diagnostic consideration in patients with new onset heart failure, arrhythmia, or electrical storm.

Recent insights into mechanisms and clinical approaches to electrical storm

Electrical storm, characterized by repetitive ventricular tachycardia/fibrillation (VT/VF) over a short period, is becoming commoner with widespread use of implantable cardioverter-defibrillator (ICD) therapy. Electrical storm, sometimes called "arrhythmic storm" or "VT-storm", is usually a medical emergency requiring hospitalization and expert management, and significantly affects short- and long-term outcomes. This syndrome typically occurs in patients with underlying structural heart disease (ischemic or non-ischemic cardiomyopathy) or inherited channelopathies. Triggers for electrical storm should be sought but are often unidentifiable. Initial management is dictated by the hemodynamic status, while subsequent management typically involves ICD interrogation and reprogramming to reduce recurrent shocks, identification/management of triggers like electrolyte abnormalities, myocardial ischemia, or decompensated heart failure, and antiarrhythmic-drug therapy or catheter ablation. Sympathetic nervous system activation is central to the initiation and maintenance of arrhythmic storm, so autonomic modulation is a cornerstone of management. Sympathetic inhibition can be achieved with medications (particularly beta-adrenoreceptor blockers), deep sedation, or cardiac sympathetic denervation. More definitive management targets the underlying ventricular arrhythmia substrate to terminate and prevent recurrent arrhythmia. Arrhythmia targeting can be achieved with antiarrhythmic medications, catheter ablation or more novel therapies such as stereotactic radiation therapy that targets the arrhythmic substrate. Mechanistic studies point to adrenergic activation and other direct consequences of ICD-shocks in promoting further arrhythmogenesis and hypocontractility. Here, we review the pathophysiologic mechanisms, clinical features, prognosis, and therapeutic options for electrical storm. We also outline a clinical approach to this challenging and complex condition, along with its mechanistic basis.

Clinical management of electrical storm: a current overview

The number of patients affected by electrical storm has been continuously increasing in emergency departments. Patients are often affected by multiple comorbidities requiring multidisciplinary interventions to achieve a clinical stability. Careful reprogramming of cardiac devices, correction of electrolyte imbalance, knowledge of underlying heart disease and antiarrhythmic drugs in the acute phase play a crucial role. The aim of this review is to provide a comprehensive overview of pharmacological treatment, latest transcatheter ablation techniques and advanced management of patients with electrical storm.

Electrical storm: Prognosis and management

Electrical storm is present when a cluster of ventricular arrhythmias (VAs) occurs within a short time frame. The most widely accepted definition is 3 or more episodes of VA within a 24-h period, although prognostic risk begins to rise when 2 or more events occur within 3months. Electrical storm often presents as a medical emergency in the form of recurrent implantable cardiac defibrillator (ICD) shocks, recurrent syncope in patients with no ICD or low cardiac output symptoms. Management often requires a multimodality approach including ICD management, pharmacologic therapy, catheter ablation and modulations of the autonomic nervous system. In this article, we review the definition, prognosis and management of electrical storm.

Bidirectional ventricular tachycardia induced by respiratory alkalosis mediated hypokalemia in a patient with acute ischemic heart failure

Bidirectional ventricular tachycardia (BVT) is a rare arrhythmia that is generally observed in patients with catecholaminergic ventricular tachycardia or digoxin overdose. Herein, we present a case of BVT and electrical storm (ES) in an acute ischemic heart failure patient that is typically induced by hypokalemia. The patient was in invasive mechanical ventilator (MV) support and hypokalemia was related to acute respiratory alkalosis and that caused refractory hypokalemia despite intravenous (IV) potassium replacement. We also discuss our approach to solve refractory hypokalemia caused by respiratory alkalosis.

Stellate ganglion blockade for treating refractory electrical storm: a historical cohort study

BACKGROUND

Stellate ganglion blockade (SGB) has been used to treat electrical storm (ES) refractory to antiarrhythmic therapy or to stabilize patients before more definitive intervention. Nevertheless, its efficacy is not well understood, with only a few case reports and retrospective case series in the literature.

METHODS

We conducted a historical cohort study on patients with drug-refractory ES who underwent ultrasound-guided unilateral SGB from 1 January 2010 until 19 July 2019 at two hospital sites. Stellate ganglion blockade was performed with variable combinations of bupivacaine, lidocaine, ropivacaine, and dexamethasone. We collected data on demographic and procedural characteristics, the number of arrhythmias and defibrillation episodes, antiarrhythmic and anticoagulant medication, left ventricular ejection fraction (EF), and respiratory support requirement.

RESULTS

We identified N = 13 patients; their mean (standard deviation [SD]) age was 64 (13) yr, and 10 (77%) were male. The baseline mean (SD) number of overall arrhythmia and defibrillation episodes per day were 9 (6) and 4 (3), respectively; the mean (SD) pre-SGB EF was 23 (7)%. Seven patients (54%) received dexamethasone in addition to local anesthetic for SGB. One patient experienced hypotension after SGB. Arrhythmias and defibrillation episodes significantly decreased at 24, 48, 72, and 96 hr after SGB; at 96 hr, 62% and 92% of patients had no VA and defibrillation episodes, respectively (P < 0.001 for all time points). Ejection fraction and the number of patients receiving antiarrhythmic medications or requiring respiratory support were unchanged.

CONCLUSIONS

Unilateral SGB was associated with a reduction in arrhythmias and defibrillation episodes, but did not affect antiarrhythmic medication, respiratory support, or EF. Randomized controlled trials on larger cohorts are needed to confirm these findings.

Stellate ganglion block as rescue therapy in drug-resistant electrical storm

Electrical storm or incessant ventricular tachycardia is a life-threatening condition and is associated with high morbidity and mortality. Often patients respond to traditional anti-arrhythmia treatment. However, some patients are resistant to the drug therapy and thus, pose huge challenges in effective management. Though stellate ganglion block has been found to be effective in treating patients with electrical storm, it is still under-utilized. In this case report, we successfully managed to revert the drug-resistant arrhythmia to sinus rhythm after ultrasound-guided stellate ganglion block. Earlier utilization of the block can possibly provide effective treatment in drug-resistant ventricular arrhythmias and prevent morbidity and mortality.

Effects of Apparent Temperature on the Incidence of Ventricular Tachyarrhythmias in Patients With an Implantable Cardioverter-Defibrillator: Differential Association Between Patients With and Without Electrical Storm

Background: Electrical storm (ES) has profound psychological effects and is associated with a higher mortality in patients with implantable cardioverter–defibrillator (ICD). Assessing the incidence and features of ES, is vital. Previous studies have shown winter peaks for ventricular tachyarrhythmia (VTA) in ICD patients. However, the effects of heat with a high relative humidity remain unclear. Thus, this study aimed to assess the nonlinear and lagged effects of apparent temperature [or heat index (HI)] on VTA among patients with and without ES after ICD implantation.

Methods: Of 626 consecutive patients who had ICDs implanted from January 2004 to June 2017 at our hospital, 172 who experienced sustained VTAs in ICD recording were analyzed, and their clinical records were abstracted to assess the association between VTA incidence and HI by time-stratified case-crossover analysis. Cubic splines were used for the nonlinear effect of HI, with adjustment for air pollutant concentrations.

Results: A significant seasonal effect for ES patients was noted. Apparent temperature, but not ambient temperature, was associated with VTA occurrences. The low and high HI thresholds for VTA incidence were <15° and >30°C, respectively, with a percentage change in odds ratios of 1.06 and 0.37, respectively, per 1°C. Lagged effects could only be demonstrated in ES patients, which lasted longer for low HI (in the next 4 days) than high HI (in the next 1 day).

Conclusion: VTA occurrence in ICD patients was strongly associated with low HI and moderately associated with high HI. Lagged effects of HI on VTA were noted in patients with ES. Furthermore, patients with ES were more vulnerable to heat stress than those without ES. Patients with ICD implantation, particularly in those with ES, should avoid exposure to low and high HI to reduce the risk of VTAs, improve quality of life and possibly reduce mortality.

Electrical storm in a patient with COVID-19 treated with hydroxychloroquine: A case report

Hydroxychloroquine (HCQ) is a widely used drug to treat patients with coronavirus disease 19 (COVID-19). Although evidence of its efficacy and safety remains limited and controversial, both cardiac and non-cardiac adverse events are known to be associated with its use. To our knowledge, electrical storm in patients with COVID-19, or in any case treated with HCQ, has not been reported. We report the case of a 78-year-old male with an implantable cardiac resynchronization defibrillator (CRT-D) and a non-severe form of COVID-19. After a few days of home therapy with HCQ, an electrical storm was revealed that was associated with an increase in QTc. Following admission to the intensive care unit, HCQ was discontinued and progressive reduction of the QTc with electrical stabilization was observed. This clinical case highlights the potential risk of arrythmia associated with the use of HCQ and stresses the need for close electrocardiographic monitoring, especially in patients with established heart disease.

Management of ventricular electrical storm: a contemporary appraisal

Ventricular electrical storm (VES) is a clinical scenario characterized by the clustering of multiple episodes of sustained ventricular arrhythmias (VA) over a short duration. Patients with VES are prone to psychological disorders, heart failure decompensation, and increased mortality. Studies have shown that 10–28% of the patients with secondary prevention ICDs can sustain VES. The triad of a susceptible electrophysiologic substrate, triggers, and autonomic dysregulation govern the pathogenesis of VES. The rate of VA, underlying ventricular function, and the presence of implantable cardioverter-defibrillator (ICD) determine the clinical presentation. A multi-faceted approach is often required for management consisting of acute hemodynamic stabilization, ICD reprogramming when appropriate, antiarrhythmic drug therapy, and sedation. Some patients may be eligible for catheter ablation, and autonomic modulation with thoracic epidural anesthesia, stellate ganglion block, or cardiac sympathetic denervation. Hemodynamically unstable patients may benefit from the use of left ventricular assist devices, and extracorporeal membrane oxygenation. Special scenarios such as idiopathic ventricular fibrillation, Brugada syndrome, Long and short QT syndrome, early repolarization syndrome, catecholaminergic polymorphic ventricular tachycardia, arrhythmogenic right ventricular cardiomyopathy, and cardiac sarcoidosis have been described as well. VES is a cardiac emergency that requires swift intervention. It is associated with poor short and long-term outcomes. A structured team-based management approach is paramount for the safe and effective treatment of this sick cohort.

Electrical storm: A focused review for the emergency physician

BACKGROUND

Electrical storm is a dangerous condition presenting to the Emergency Department that requires rapid diagnosis and management.

OBJECTIVE

This article provides a review of the diagnosis and management of electrical storm for the emergency clinician.

DISCUSSION

Electrical storm is defined as ≥3 episodes of sustained ventricular tachycardia, ventricular fibrillation, or shocks from an implantable cardioverter defibrillator within 24 h. Patients may present with a wide array of symptoms. Initial evaluation should include an electrocardiogram with a rhythm strip and continuous cardiac monitoring, a medication history, assessment of hemodynamic stability, and identification of potential triggers. Management includes an antiarrhythmic and a beta blocker. Refractory patients may benefit from double-sequential defibrillation or more invasive procedures such as intra-aortic balloon pumps, catheter ablation and extracorporeal membrane oxygenation for critically ill patients. These patients will typically require admission to an intensive care unit.

CONCLUSION

Electrical storm is a condition associated with significant morbidity and mortality. It is important for clinicians to be aware of the current evidence regarding the evaluation and management of these patients.

Refractory Electrical Storm in the Absence of Structural Ischemic Heart Disease

Ventricular tachycardia (VT) is characterized as a ventricular rhythm with a QRS >120 milliseconds (ms) and >100 beats-per-minute (BPM) in the absence of an aberrant conduction. It is classified as sustained when lasting >30 seconds. Risk factors associated with the development of VT include increasing age and coronary artery disease with concurrent left ventricular dysfunction, other forms of structural heart disease and acquired or congenital abnormalities in the cardiac sodium, potassium or calcium channels. Diagnosing VT is challenging based on history and physical exam alone. Combination of electrocardiogram (EKG), electrolytes and cardiac enzymes, echocardiogram, cardiac catheterization, and electrophysiology testing are required to appropriately diagnose and characterize the etiology. The case below describes an 84-year-old female with a known history of symptomatic bradycardia status post pacemaker who presented to the emergency department (ED) after a routine device check which revealed VT with associated dyspnea. The patient did not do well with medical therapy and required ablative therapy to resolve VT.

Efficacy of Stellate Ganglion Blockade in Managing Electrical Storm: A Systematic Review

BACKGROUND

The efficacy of percutaneous stellate ganglion block (SGB) for managing electrical storm (ES) is not well understood.

OBJECTIVE

To characterize the efficacy of SGB as a treatment for ES.

METHODS

We conducted literature searches using PubMed/Medline and Google Scholar, for mixed combinations of terms including "stellate ganglion block", *ganglion block (ade)", "sympathetic block (ade)" and "arrhythmia", "ventricular arrhythmia (VA)" or "tachycardia" (VT), "ventricular fibrillation" (VF), "electrical storm". Inclusion criteria were presentation with guideline-defined ES and treatment with SGB. Exclusion criteria: presentation with any supraventricular arrhythmia, VA without ES, or surgical sympathectomy. Studies lacking basic demographic data, arrhythmia description, and outcomes were excluded.

RESULTS

Of 3,374 publications reviewed, 38 patients from 23 studies met study criteria (52 ± 19.1 years, 11 F, 17 with ischemic cardiomyopathy). Anti-arrhythmics were used in all patients. Mean Left ventricular ejection fraction was 31 ± 10%. ES was triggered by acute myocardial infarction in 15 patients and QT prolongation in 7 patients. The most common local anesthetic used for SGB was bupivacaine (0.25-0.5%). SGB resulted in a significant decrease in VA burden (12.4±8.8 vs. 1.04±2.12 episodes/day, p< 0.001) and number of external and ICD shocks (10.0±9.1 vs. 0.05±0.22 shocks/day, p< 0.01). Following SGB, 80.6% of patients survived to discharge.

CONCLUSION

SGB is an effective acute treatment for ES. However, larger prospective randomized studies are needed to better understand the role of SGB in ES and other VAs.

Electrical Storm Due to Active Myocardial Ischemia in the Right Coronary Artery Territory – Case Report

Electrical storm is defined by at least three episodes of sustained ventricular tachyarrhythmias or appropriate shocks given by implantable cardiac defibrillator devices (ICD), occurring within a period of 24 hours. In the present manuscript, we present the case of a 69-year-old female patient with previous aortocoronary bypass, who was admitted from the Emergency Department after presenting several episodes of syncope in prehospital settings and presented 4 episodes of sustained ventricular tachycardia which required electrical cardioversion. The arrhythmia disappeared after percutaneous revascularization of a chronic occlusion in the right coronary artery. In this case, the implantation of an ICD was avoided, as a reversible cause of ES has been identified and treated.

Management of ventricular storm with thoracic epidural anesthesia

The incidence of recurrent ventricular arrhythmias is increasing these days. Ventricular electrical storm can be of three types as follows: monomorphic ventricular tachycardia (VT), polymorphic VT, and ventricular fibrillation. The mechanism of ventricular storm is complex, and its management is quite a challenge for the clinicians due to its life-threatening consequences. We report a case of ventricular storm in whom all the conventional methods for the management of arrhythmias were ineffective, and the case is managed effectively with thoracic epidural anesthesia (TEA). A 60-year-old male patient was admitted to recurrent ventricular arrhythmias. He received defibrillator shocks and other antiarrhythmic drugs, but he was not responding to the treatment. We managed to revert the ventricular arrhythmias to the sinus rhythm with TEA. Ventricular storm is a challenging complication, which can be managed effectively with timely diagnosis and effective management.

A successful catheter ablation of a ventricular fibrillation

Malignant ventricular arrhythmias are challenging to manage, requiring a multidisciplinary approach. The mechanism, which triggers ventricular fibrillation (VF) associated with ventricular extrasystoles has not been clarified yet, however, abolishing ventricular extrasystoles may stop ventricular fibrillation in these patients. By this case presentation, we aimed to present a successful treatment of an electrical storm (ES), which developed after an acute myocardial infarction, by catheter ablation.

Ventricular Tachycardia with ICD Shocks: When to Medicate and When to Ablate

PURPOSE OF REVIEW

Ventricular tachycardia occurrence in implantable cardioverter defibrillator (ICD) patients may result in shock delivery and is associated with increased morbidity and mortality. In addition, shocks may have deleterious mechanical and psychological effects. Prevention of ventricular tachycardia (VT) recurrence with the use of antiarrhythmic drugs or catheter ablation may be warranted. Antiarrhythmic drugs are limited by incomplete efficacy and an unfavorable adverse effect profile. Catheter ablation can be effective but acute complications and long-term VT recurrence risk necessitating repeat ablation should be recognized. A shared clinical decision process accounting for patients' cardiac status, comorbidities, and goals of care is often required.

RECENT FINDINGS

There are four published randomized trials of catheter ablation for sustained monomorphic VT (SMVT) in the setting of ischemic heart disease; there are no randomized studies for non-ischemic ventricular substrates. The most recent trial is the VANISH trial which randomly allocated patients with ICD, prior infarction, and SMVT despite first-line antiarrhythmic drug therapy to catheter ablation or more aggressive antiarrhythmic drug therapy. During 28 months of follow-up, catheter ablation resulted in a 28% relative risk reduction in the composite endpoint of death, VT storm, and appropriate ICD shock (p = 0.04). In a subgroup analysis, patients having VT despite amiodarone had better outcomes with ablation as compared to increasing amiodarone dose or adding mexiletine. There is evidence for the effectiveness of both catheter ablation and antiarrhythmic drug therapy for patients with myocardial infarction, an implantable defibrillator, and VT. If sotalol is ineffective in suppressing VT, either catheter ablation or initiation of amiodarone is a reasonable option. If VT occurs despite amiodarone therapy, there is evidence that catheter ablation is superior to administration of more aggressive antiarrhythmic drug therapy. Early catheter ablation may be appropriate in some clinical situations such as patients presenting with relatively slow VT below ICD detection, electrical storms, hemodynamically stable VT, or in very selected patients with left ventricular assist devices. The optimal first-line suppressive therapy for VT, after ICD implantation and appropriate programming, remains to be determined. Thus far, there has not been a randomized controlled trial to compare catheter ablation to antiarrhythmic drug therapy as a first-line treatment; the VANISH-2 study has been initiated as a pilot to examine this question.

Percutaneous extracorporeal membrane oxygenation in electrical storm: five case reports addressing efficacy, transferring allowance or radiofrequency ablation support

Extracorporeal membrane oxygenation systems have undergone rapid technological improvements and are now feasible options for medium-term support of severe cardiac or pulmonary failure. We report five cases of electrical storm that was rescued by the insertion of peripheral veno-arterial extracorporeal membrane oxygenation systems. This device could help to restore systemic circulation as well as permitting organ perfusion in patients with cardiogenic shock in relation to electrical storm thus achieving greater electrical stability. Also, in some cases extracorporeal membrane oxygenation support could facilitate electrophysiology study.

First Report of Survival in Refractory Ventricular Fibrillation After Dual-Axis Defibrillation and Esmolol Administration

There is a subset of patients who suffer a witnessed ventricular fibrillation (VF) arrest and despite receiving reasonable care with medications (epinephrine and amiodarone) and multiple defibrillations (3+ attempts at 200 joules of biphasic current) remain in refractory VF (RVF), also known as electrical storm. The mortality for these patients is as high as 97%. We present the case of a patient who, with a novel approach, survived RVF to outpatient follow up.

Electrical Storm: Incidence, Prognosis and Therapy

The term "electrical storm" indicates a life-threatening clinical condition characterized by the recurrence of hemodynamically unstable ventricular tachycardia and/or ventricular fibrillation, in particular in patients with ICD implanted for primary or secondary prevention. Although there isn't a shared definition of electrical storm, nowadays the most accepted definition refers to three or more separate arrhythmia episodes leading to ICD therapies including antitachycardia pacing or shock occurring over a single 24 hours' time period. Clinical presentation can be dramatic and triggering mechanism are not clear at all yet, but electrical storm is associated with high mortality rates and low patients quality of life, both in the acute phase and in the long term. The first line therapy is based on antiarrhythmic drugs to suppress electrical storm, but in refractory patients, interventions such as catheter ablation or in some cases surgical cardiac sympathetic denervation might be helpful. Anyhow, earlier interventional management can lead to better outcomes than persisting with antiarrhythmic pharmacologic therapy and, when available, an early interventional approach should be preferred.

Optimal antiarrhythmic drug therapy for electrical storm

Electrical storm, defined as 3 or more separate episodes of ventricular tachycardia or ventricular fibrillation within 24 hours, carries significant morbidity and mortality. These unstable ventricular arrhythmias have been described with a variety of conditions including ischemic heart disease, structural heart disease, and genetic conditions. While implantable cardioverter defibrillator implantation and ablation may be indicated and required, antiarrhythmic medication remains an important adjunctive therapy for these persons.

Optimal programming management of ventricular tachycardia storm in ICD patients

Ventricular tachycardia storm (VTS) is defined as a life-threatening syndrome of three or more separate episodes of ventricular tachycardia (VT) leading to implantable cardioverter defibrillator (ICD) therapy within 24 hours. Patients with VTS have poor outcomes and require immediate medical attention. ICD shocks have been shown to be associated with increased mortality in several studies. Optimal programming in minimization of ICD shocks may decrease mortality. Large controlled trials showed that long detection time and high heart rate detection threshold reduced ICD shock burden without an increase in syncope or death. As a fundamental therapy of ICD, antitachycardia pacing (ATP) can terminate most slow VT with a low risk of acceleration. For fast VT, burst pacing is more effective and less likely to result in acceleration than ramp pacing. One algorithm of optimal programming management during a VTS is presented in the review.

[Catheter ablation of electrical storm: ready for prime time?]

Electrical storm is an increasingly recognized clinical entity. It is generally defined as the occurrence of ≥ 3 episodes of potentially life-threatening ventricular arrhythmias during a time span of 24 h. Apart from pharmacological treatment options, catheter ablation remains a relatively novel, promising addition to the armamentarium of the cardiologist. Here, we will review the study data on ablation of patients with electrical storm.