Europace (2023) 25, 1277–1283 EHRA SURVEY https://doi.org/10.1093/europace/euac151 Contemporary management of ventricular electrical storm in Europe: results of a European Heart Rhythm Association Survey Enrico Baldi 1, Giulio Conte 2*, Katja Zeppenfeld 3, Radosław Lenarczyk4, Jose M. Guerra5, Michal M. Farkowski 6, Carlo de Asmundis 7, and Serge Boveda 7,8 1 Division of Cardiology, Fondazione IRCCS Policlinico San Matteo, Pavia, Italy; 2Cardiocentro Ticino Institute, Ente Ospedaliero Cantonale, Via Tesserete 48, Lugano 6900, Switzerland; 3 Department of Cardiology, Heart Lung Centre, Leiden University Medical Centre, Leiden, The Netherlands; 4Division of Medical Sciences in Zabrze, Department of Cardiology, Congenital Heart Diseases and Electrotherapy, Silesian Center for Heart Diseases, The Medical University of Silesia, Zabrze, Poland; 5Department of Cardiology, Hospital de la Santa Creu i Sant Pau, IIB SANT PAU, CIBERCV, Universitat Autónoma de Barcelona, Barcelona, Spain; 6II Department of Heart Arrhythmia, National Institute of Cardiology, Warsaw, Poland; 7Heart Rhythm Management Centre, Postgraduate Program in Cardiac Electrophysiology and Pacing, Universitair Ziekenhuis Brussel – Vrije Universiteit Brussel, European Reference Networks Guard- Heart, Brussels, Belgium; and 8Cardiology-Heart Rhythm Management Department, Clinique Pasteur, Toulouse, France Received 4 August 2022; accepted after revision 4 August 2022; online publish-ahead-of-print 5 October 2022 Abstract Electrical storm (ES) is a predictor of mortality, and its treatment is challenging. Moreover, not all potential therapeutic strat­ egies are available in all hospitals, and a standardized approach among European centres is lacking. The aim of this European Heart Rhythm Association (EHRA) survey was to assess the current management of patients with ES both in the acute and post-acute phases in 102 different European centres. A 20-item online questionnaire was sent out to the EHRA Research Network Centres. The median number of patients with ES treated annually per centre is 10 (IQR 5–15). The possibility of using autonomic modulation (e.g. percutaneous stellate ganglion block or thoracic epidural anaesthesia) for the acute ES treatment is available in only 29.3% of the centres. Moreover, although over 80% of centres perform ventricular tachycardia ablation, this procedure is available 24/7 in only 16.5% of the hospitals. There is a significant heterogeneity among centres regarding the availability of AADs and their use before deciding to proceed with a non-AAD strategy; specifically, 4.4% of centres use only one drug, 33.3% use two drugs, and 12.2% >two drugs, while about 50% of the centres decide based on individual patient’s characteristics. Regarding the type of AADs used for the acute and post-acute management of ES pa­ tients, important variability is reported depending upon the underlying heart disease. Most patients considered for percu­ taneous ablation have structural heart disease. Only 46% of centres refer patients to psychological counselling after ES. -Keywords -------------------------------------------------------------------------------------------------------------------------------------------------------------- Electrical storm • Ventricular arrhythmias • Arrhythmic storm • Catheter ablation • Autonomic modulation • EHRA survey Anti-arrhythmic drug (AAD) therapy is the first-line choice for treating Introduction an ES, but is often ineffective, especially in the first hour from the arrhyth­ mic onset.9 Therefore, in most cases other interventions are needed, Electrical storm (ES) is defined as the occurrence of three or more epi­ sodes of sustained ventricular arrhythmia [ventricular tachycardia (VT) both in the acute phase and after patient stabilization.10 Acute manage­ or ventricular fibrillation (VF)] occurring within 24 h, requiring either ment includes implantable cardiac defibrillator (ICD) reprogramming,4 anti-tachycardia pacing (ATP) or cardioversion/defibrillation, with deep sedation, or general anaesthesia,11,12 autonomic modulation each event separated by at least 5 min.1–6 Electrical storm is considered through thoracic epidural anaesthesia 13 or stellate ganglion block,14–16 a significant predictor of mortality, irrespective of the underlying heart extracorporeal membrane oxygenation (ECMO) for haemodynamically disease and the history of previous VT/VF.7 unstable patients,17,18 and urgent catheter ablation.10,19 Once the patient The management of ES is challenging, and a multidisciplinary and multi- is stable, elective catheter ablation (endocardial and/or epicardial),20,21 faceted approach is often required to ensure an effective treatment.8 optimization of AAD therapy, cardiac sympathetic denervation,22 and * Corresponding author. Tel: +41 91 811 53 50, Fax: +41918115396. E-mail address: giulio.conte@eoc.ch © The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited. 1278 EHRA Survey Electrophysiology laboratory (Ep Lab) What’s new? The following are a list of EP procedures available in the different institu­ tions: 84.3% of the centres performed complex endocardial ablations in­ • A standardized approach among European centres for treating elec­ trical storm (ES) is lacking. cluding VT ablation, 1% complex endocardial ablations but no VT ablation, 3.9% conventional ablation procedures (without 3D mapping), • Ventricular tachycardia ablation 24 h/day and 7 days/week is avail­ able in only 16.5% of the centres for the acute ES treatment and and 2.9% diagnostic procedures only (e.g. electrophysiological studies). Epicardial ablation was available in 66.3% of the centres who perform VT autonomic modulation (percutaneous stellate ganglion block or ablation, while surgical ablation in 30.2% of them. No EP procedures thoracic epidural anaesthesia) is available in only 39.2%. were performed in 7.8% of centres. • There is a significant heterogeneity among centres regarding the availability of AADs and their use before deciding to proceed with Among the 85 centres performing catheter-based acute management of electrical storm, ablation was available only during daytime and workdays in a non-AAD strategy. 83.5%, or 24/7 in the remaining 16.5%. Acute management of Electrical storm 23–25 Concerning the strategies available for the acute management of ES, device non-invasive cardiac ablation may be helpful in preventing ES (ICD/CRT) programming was available in the vast majority of centres recurrences. (94.1%), followed by deep sedation (83.3%), implant of temporary pace­ Some therapeutic strategies for ES may not be available in all maker to avoid bradycardia-induced ventricular arrhythmias (81.4%), gen­ hospitals. A standardized approach among European centres is lacking eral anaesthesia (74.5%), less-common used pharmacotherapy (e.g. and it is unknown how ES is managed across centres. Furthermore, mexiletine, isoproterenol) (74.5%) and acute catheter ablation (71.6%). 2015 ESC guidelines on the management of ventricular arrhythmias In contrast, autonomic modulation [e.g. percutaneous stellate ganglion do not provide any specific recommendations or structured approach block (PSGB) or thoracic epidural anaesthesia] was only available in a small for patients with ES.26 proportion of centres (39.2%); among them, 82.5% used to perform PSGB and 25% thoracic epidural anaesthesia. The aim of this European Heart Rhythm Association (EHRA) survey was to assess the current management of patients with ES in the acute and post-acute phases in different European centres. Moreover, the Pharmacological strategy availability of different pharmacological and non-pharmacological inter­ A list of available anti-arrhythmic drugs (AADs) is presented in Figure 1. ventions was investigated. Amiodarone, propafenone, verapamil/diltiazem, lidocaine, and sotalol were available in more than 90% of the centres. The use of specific drugs in an individual patient according to the presumed underlying heart disease that caused the ES is presented in Table 1. The heterogeneity concerning Methods the use of AADs is highlighted in the table. The number of drugs administered before deciding to proceed with a The EHRA Scientific Initiatives Committee conducted the present centre- non-AAD strategy varied between centres; 4.4% of centres reported using based survey. A 20-item online questionnaire (Supplementary material only one drug, 33.3% two drugs, and 12.2% >2 drugs. The remaining half of online, File S1) was developed to collect information about the current the centres answered that the number of drugs used depended on the pa­ therapeutic management of patients with ES in Europe. The first draft of tients’ characteristics (i.e. left ventricular ejection fraction, heart failure, the questionnaire was prepared by E.B. and G.C. and was then reviewed haemodynamic status, chronic obstructive pulmonary disease). by experts (K.Z., R.L., S.B.). The link was sent out to the EHRA Research Network Centres. A total of 102 respondents completed the questionnaire included in this analysis; hence the results are reported as number and per­ Non-pharmacological strategies centage of 102, unless specified otherwise. In case of missing response to a The different non-AAD therapy strategies in case of pharmacological treat­ specific question, the total number of replies collected for that question is ment failure and according to the presumed underlying heart disease are provided in the respective figure legend. presented in Table 2. Although catheter ablation was the most chosen strat­ The respondents represented centres from the 20 European countries: egy in patients with coronary artery disease or premature ventricular con­ Austria, Belgium, Bulgaria, Croatia, France, Germany, Greece, Ireland, Israel, tractions (PVCs)-induced VF, deep sedation or general anaesthesia were, in Italy, Malta, The Netherlands, Poland, Romania, Serbia, Spain, Sweden, general, the most consistently chosen therapies and the main ones in pa­ Switzerland, Turkey, and UK. Among participating centres, 64.4% were univer­ tients with Brugada syndrome or unknown aetiology. Temporary pacing sity hospitals, 28.7% non-university public hospitals, and 6.9% private hospitals. was the most frequently used therapy for patients with LQTS. Deactivating appropriate anti-tachycardia ICD therapies was considered in all cases of ES by 18% of respondents, while 79.8% only considered it to avoid unnecessary therapies (e.g. repetitive, self-terminating VT), and 2.2% Infrastructures for electrical storm of respondents never considered deactivating anti-tachycardia therapies. Of management those who considered deactivating ICD therapies, 48.1% deactivated ICD The reported median number of patients with ES treated annually per cen­ shock therapy only, whereas 43.2% deactivated both shock and ATP ther­ tre was 10 (IQR 5–15). The possibility of performing acute percutaneous apies. A total of 8.1% only used magnet placement to deactivate therapies. coronary intervention (PCI) 24/7 was reported by 87.2% of respondents, acute PCIs available only during daytime and workdays by 7.8%, and no availability of PCI in 5%. The vast majority of centres performed ICD im­ Post-acute and chronic management of ES plantation (95.1%). Post-acute and chronic use of specific AADs to prevent ES recurrence ac­ Regarding the specific type of acute haemodynamic support, intra-aortic cording to the presumed underlying heart disease is presented in Table 3. A balloon pump (IABP) was available in 84.3%, percutaneous mechanical sup­ total of 27 centres (26%) reported having referred patients to other centres port (e.g. Impella) in 54.9%, ECMO in 64.7%, while 6.9% of the hospitals had for the post-acute interventional management of ES (i.e. catheter ablation). no available haemodynamic support. A total of 79 respondents (77.4%) re­ Cardiac sympathetic denervation (thoracoscopic or surgical) was available ported that >1 specialist are usually involved in the treatment of ES, while in 20.6% of locations. The proportion of patients with a diagnosis of VT the remaining 22.6% stated that there is usually only one specialist to man­ storm considered by the respondents for a percutaneous ablation, accord­ age ES: electrophysiologists being present in 87.3% of cases, followed by ing to the underlying heart disease, is presented in Figure 2. Most patients general cardiologists (56.8%), Intensive Cardiac Care specialists (56.8%), an­ considered for ventricular ablation were those with ischaemic heart disease, esthesiologists (28.4%), and cardiac surgeons (6.8%). while those with an inherited arrhythmia condition were rarely referred for EHRA Survey 1279 Availability across centres of different anti-arrhythmic drugs 99.0% 99.0% 98.0% 100% 94.1% 92.2% 90% 85.3% 80% 73.5% 69.6% 70% 66.7% 60% 51.0% 50% 41.2% 39.2% 40% 38.2% 30% 20% 10% 0% ne e l e e ol e ne l e e m e lo o n n id in id id tin ol ol ze ta ro ai no di in az m m m ad ile So c ni a da a na ra e do Es ol lti ex ec ui N af py io an di ai Q Li op M Fl Am il/ oc o R is m Pr Pr D pa ra Ve Figure 1 Anti-arrhythmic drugs available in the European countries. ablation. Of note, 47 centres (46%) declared referring patients to psycho­ in one-third of the centres. However, the adrenergic nervous logical counselling after an electrical storm. system’s hyperactivity plays a significant role in favouring ventricular arrhythmias 27–29 and the maintenance of the vicious circle, especially during recurrent ICD-shocks.30 The possibility of acutely reducing Discussion ventricular arrhythmias by blocking the left stellate ganglion has been The findings of this survey highlight several features of the current man­ known for decades.31 Recent reports from different centres have de­ agement of ES across Europe: (i) acute autonomic modulation is avail­ monstrated the potential therapeutic effect of autonomic modulation able in a relatively small proportion of centres; (ii) although more than in dramatically reducing arrhythmic recurrences during ES using thor­ 80% of centres perform VT ablation, availability of this therapy for 24 h/ acic epidural anaesthesia13 or PSGB14,15,32,33 in patients with different day and 7 days/week is reported in only a small percentage of centres; heart conditions (either ischaemic, non-ischaemic, and genetically de­ (iii) there is significant heterogeneity among centres about the use of termined cardiopathies) that caused the arrhythmic storm. This low AADs before referring patients for a non-AAD strategy; (iv) the type rate of acute use of autonomic modulation has different possible expla­ of AAD used for the acute and post-acute management of ES patients nations: among them, the scarce knowledge about the possibility of is variable and depends on the underlying heart disease; (v) psychologic­ using such techniques for anti-arrhythmic purposes, the perception al counselling is considered in nearly half of the patients who have ex­ that catheter ablation is of easier applicability and the fact that electro­ perienced an ES; (vi) deep sedation and/or general anaesthesia is the physiologists believe that special skills, often of formal anesthesiologic most consistently chosen strategy throughout the spectrum of pertinence, are required to perform these techniques safely. aetiologies. Although thoracic epidural anaesthesia requires a trained anesthesiolo­ Our survey confirms that ES is an important clinical problem in daily gist, PSGB can be safely performed by cardiologists using only anatomic cardiology practice, as all centres report treating at least one patient landmarks without imaging guidance,15,33 as known since the Leriche every month. However, the condition could be overestimated since and Fontain studies of the early 1900s.34 The reported rate of compli­ many of the respondents could be tertiary centres where these patients cations is very low, suggesting that this type of technique should be­ are referred to. Despite the fact the treatment of ES involves more than come part of the modern electrophysiologists’ expertise in treating one specialist in about three-fourths of the centres, the role of electro­ arrhythmic storm patients. physiologists appears central, as they were involved in about 90% of cases. Cather ablation in patients with electrical Unfortunately, since many gaps in knowledge and evidence exist in this topic, standardizing treatment for ES patients is difficult.26 This is storm also confirmed in our survey, where a high heterogeneity was present Currently, urgent catheter ablation is a Class I-B recommendation among centres concerning the different therapeutic strategies to treat for the treatment of patients presenting with arrhythmic storm, es­ these patients. pecially those with scar-related heart disease, left ventricular systolic dysfunction, or idiopathic VF triggered by PVC originating from the Purkinje system.26 Our survey highlights that only a minority of cen­ Autonomic modulation for the acute tres offers catheter ablation 24/7 despite the fact the majority per­ management of electrical storm form this procedure. In the vast majority of centres, catheter For the acute management of ES, autonomic modulation using PSGB ablation is available only during daytime and workdays; as a result, or thoracic epidural anaesthesia is considered and performed only other strategies are needed to acutely stabilize the patients while Table 1 Drugs considered in the acute treatment of electrical storm according to the presumed underlying heart disease 1280 Amiodarone Beta-blockers Flecainide Procainamide Propafenone Verapamil/diltiazem Quinidine Lidocaine Mexiletine ............................................................................................................................................................................................ Chronic coronary artery disease 94.5% 96.7% 4.4% 20.9% 5.5% 18.7% 8.8% 71.4% 57.1% Cardiomyophaties (dilated, hypertrophic, AVC) 95.6% 93.4% 14.3% 19.8% 4.4% 7.7% 12.1% 50.6% 49.5% Brugada syndrome/early repolarization 17.9% 39.3% 4.8% 8.3% 2.4% 6.0% 67.9% 13.1% 8.3% Acquired LQTS 9.0% 87.2% 5.1% 1.3% 1.3% 2.6% 5.1% 20.5% 19.2% Inherited LQTS 7.2% 89.2% 14.5% 2.4% 3.6% 3.6% 3.6% 18.1% 26.5% PVCs-triggered VF 77.9% 86.1% 34.9% 10.5% 26.7% 25.6% 10.5% 45.4% 25.6% Unknown aetiology 92.9% 89.4% 18.8% 10.6% 15.3% 17.7% 11.8% 44.7% 30.6% AVC, arrhythmogenic ventricular cardiomyopathy; LQTS, long QT syndrome; PVC, premature ventricular contractions; VF, ventricular fibrillation. Table 2 Preferred non-anti-arrhythmic drugs strategy in case of pharmacological treatment failure according to the presumed underlying heart disease, in the acute treatment of electrical storm Deep Intubation/ Percutaneous Intra-aortic Extracorporeal Autonomic Temporary Acute sedation general mechanical support balloon pump membrane oxygenator modulation PM catheter anesthesia (e.g. Impella) (ECMO) ablation ............................................................................................................................................................................................ Chronic coronary artery 59.1% 58.0% 19.3% 25.0% 25.0% 18.2% 34.1% 77.3% disease Cardiomyopathies (dilated, 65.5% 60.9% 23.0% 17.2% 26.4% 26.4% 28.7% 60.9% hypertrophic, AVC) Brugada syndrome/early 66.7% 51.3% 5.1% 2.6% 9.0% 14.1% 23.1% 38.5% repolarization Acquired LQTS 60.8% 53.2% 5.1% 3.8% 13.9% 21.5% 68.4% 8.9% Inherited LQTS 64.6% 57.0% 3.8% 2.5% 12.7% 29.1% 62.0% 8.9% PVCs-triggered VF 65.5% 52.4% 4.8% 2.4% 13.1% 20.2% 35.7% 70.2% Unknown aetiology 72.8% 60.5% 7.4% 7.4% 21.0% 24.7% 25.9% 45.7% AVC, arrhythmogenic ventricular cardiomyopathy; LQTS, long QT syndrome; PVC, premature ventricular contractions; VF, ventricular fibrillation; PM, pacemaker. EHRA Survey EHRA Survey 1281 waiting for an interventional strategy or an early referral to another Flecainide Sotalol Procainamide Propafenone Verapamil Procainamide Ranolazine Quinidine Mexiletine Disopyramide Nadolol ............................................................................................................................................................................................ centre where ablation is available in higher-risk patients. 11.3% 23.5% 29.7% 23.1% Table 3 The use of specific anti-arrhythmic drugs, according to the presumed underlying heart disease in the post-acute and chronic management after 8.6% 2.8% 9.5% Anti-arrhythmic drug therapy Our results highlight differences among centres regarding the avail­ ability of anti-arrhythmic drugs, especially those of less-common use, but that could be useful to treat an ES patient both acutely (e.g. pro­ cainamide, quinidine, and esmolol) or in the post-acute management 2.5% 5.0% 0.0% 0.0% 2.7% 0.0% 0.0% (e.g. mexiletine and sotalol). Moreover, as expected, there is a signifi­ cant variability in anti-arrhythmic drug use according to the pre­ sumed underlying heart disease, which shows the difficulty in standardizing the treatment of patients with ES. A special role is re­ 35.8% 27.5% 10.3% 18.9% 20.5% 16.2% 7.0% served for beta-blockers, which are used by ∼80–90% of centres for all types of heart disease (except Brugada syndrome).35,36 A great variability regarding the number of drugs commonly used in different centres before referring the patient to a non-AAD strat­ 71.8% 15.4% 4.9% 8.8% 1.5% 5.4% 8.1% egy is also shown in this study. Importantly, only a few centres used more than two AADs before using a non-AAD therapy, with most deciding according to the patient’s characteristics. These differences between centres probably reside in the availability and expertise in 24.7% 10.0% using non-AADs strategies for treating this type of patient and in 1.4% 4.4% 1.4% 1.3% 8.1% the lack of clear and standardized guideline-based recommendations. Other acute and post-acute management aspects 1.2% 0.0% 1.4% 0.0% 0.0% 2.6% 1.4% Almost all the centres proceed to deactivate at least direct current-shock therapies. This seems to be very important in managing such patients as repeated ICD-shocks may enhance sympathetic activ­ ity, trigger additional arrhythmia,30,37 cause major anxiety, and even in­ 19.2% 13.5% 7.4% 5.0% 1.4% 4.4% 0.0% crease the risk of mortality.38 Haemodynamic mechanical support is available almost in all the cen­ tres, and this represents an option to be considered in the early man­ agement of haemodynamically unstable ES patients,10 also as a bridge to catheter ablation.39 23.1% 3.7% 2.5% 2.8% 1.5% 0.0% 9.5% Concerning the post-acute and chronic management of ES patients, a non-negligible percentage of centres refer their patients to another centre to perform VT ablation. These points out the importance of en­ hanced collaborations among centres to treat ES patients and ensure the best chance of survival, also in the acute setting. Ventricular tachy­ cardia ablation is effective in reducing recurrences of arrhythmic storms 3.7% 6.3% 0.0% 0.0% 1.4% 3.9% 1.4% and ventricular arrhythmias in patients with structural heart disease and in improving their prognosis.20,21 According to this survey, the percent­ 37.0% 37.5% 25.6% 20.3% age of patients referred to VT ablation is different according the under­ 1.4% 4.4% 1.4% lying heart disease, with a greater percentage of patients referred to an interventional procedure among those with ischaemic heart disease, followed by those with non-ischemic cardiomyopathies. This is in line 10.0% 26.9% 18.9% with current recommendations, which favour VT ablation in patients 2.5% 4.2% 4.4% 9.5% with a scar-related mechanism.6,26 Finally, nearly half of the centres refer patients to psychological coun­ selective blockers Amiodarone Cardio- beta-1- selling after electrical storm. This represents an important issue, often 91.4% 87.5% 39.4% 86.8% 81.1% 87.2% 86.5% neglected by the clinicians, which should be further improved. It has been already highlighted, indeed, that ES patients are at higher risk of developing psychological disorders,7 in particular severe anxiety and de­ pression.40 Therefore, based on published data, psychological counsel­ ling should be warranted to all ES patients after clinical stabilization. 93.8% 90.0% 16.9% 62.8% 78.4% 4.4% 5.4% arrhythmic storm Conclusions Unknown aetiology Brugada syndrome/ PVCs-triggered VF Cardiomyopathies Chronic coronary repolarization artery disease hypertrophic, Acquired LQTS Inherited LQTS The treatment of ES represents a challenge, and the electrophysiologist (dilated, plays a central role in managing these patients. A substantial heterogen­ AVC) early eity is highlighted among European centres, especially concerning the availability and use of autonomic modulation techniques. Although it is difficult to standardize the treatment of such patients, further efforts 1282 EHRA Survey Proportion of patients with ES considered by the respondents to the survey for a percutaneous ablation according to the presumed underlying heart disease 70% 60% 50% 40% 0–25% 25–50% 30% 50–75% >75% 100% 20% 10% 0% Ischemic heart disease Non-ischemic cardiomyopathy Inherited arrhythmia diseases Figure 2 Proportion of patients with ES considered by the respondents to the survey for a percutaneous ablation, according to the presumed under­ lying heart disease. are warranted to provide specific recommendations in future guidelines 4. Hohnloser SH, Al-Khalidi HR, Pratt CM, Brum JM, Tatla DS, Tchou P et al. Electrical and to increase the expertise of European electrophysiologists in the storm in patients with an implantable defibrillator: incidence, features, and preventive therapy: insights from a randomized trial. 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