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Background Ventricular arrhythmias (VAs), including ventricular tachycardia and ventricular fibrillation, present substantial therapeutic challenges due to their high morbidity, mortality, and increasing prevalence. Current treatments often prove infeasible or inadequate in patients with refractory VAs. Purpose To evaluate the safety and effectiveness of CT-guided left stellate ganglion cryoneurolysis (SGC) in the treatment of refractory VAs. Materials and Methods This retrospective study reviewed all consecutive patients with refractory VAs who underwent SGC between June 2020 and December 2023 at two tertiary care centers. Patients with refractory VAs who underwent CT-guided left SGC were included. No patients were excluded. Data on preprocedural clinical status, procedural approach, procedural outcomes, and adverse events were analyzed. The pre- and postprocedural number of defibrillations were compared using the Wilcoxon matched-pairs signed rank test. Results A total of 17 patients (mean age, 60.4 years ± 2.7 [standard error of the mean]; 14 male) were included; seven patients (41%) were receiving β-adrenergic blocking agents. The mean number of antiarrhythmic medications per patient was 2.2 ± 0.2. CT-guided left SGC led to a significant reduction in defibrillations, from a median of 3 (IQR, 3-15) to 0 (IRQ, 0-0) in the 24 hours before and after the procedure, respectively ( P < .001). Clinical success, defined as freedom from defibrillation within the preceding 24-hour period, was achieved in 14 of 17 patients (82%) 24 hours after and 15 of 17 patients (88%) 72 hours after the procedure. Of 17 patients, 12 (71%) proceeded to additional procedural management after SGC. At a mean follow-up of 469.2 days ± 90.8, 14 of 17 patients (82%) were alive. No moderate or high-grade adverse events were observed; mild adverse events included left upper extremity neurapraxia ( n = 1) and transient Horner syndrome ( n = 3). Conclusion CT-guided left SGC demonstrated promising effectiveness and safety in treating patients with refractory VAs. Thus, SGC warrants consideration for inclusion in a multidisciplinary treatment algorithm for VAs. © RSNA, 2024 See also the editorial by Cadour and Scemama in this issue.

The occurrence of ventricular tachycardia (VT) in patients with acute myocardial infarction (AMI) is associated with poor prognosis. Drug therapy and implantable cardioverter-defibrillators (ICDs) are effective methods to prevent sudden death. Radiofrequency (RF) catheter ablation can map the matrix and mechanism of VT, thereby effectively reducing the occurrence of ICD discharge. This paper reports on the case of a middle-aged man who underwent emergency percutaneous coronary intervention for AMI and developed VT and ventricular fibrillation on day 7 after reperfusion. An ICD was implanted. On day 19, he received catheter ablation because of refractory monomorphic ventricular tachycardia and frequent discharge of the ICD. After three months, the patient had not experienced any further ventricular tachycardia attacks. The conclusion is that RF catheter ablation can resolve the ES after myocardial infarction and significantly reduce the occurrence of ICD discharges., Competing Interests: Declaration of competing interest The authors declare that they have no competing interests., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Electrical storm (ES) is a life-threatening condition, associated with substantial early and subacute mortality. Catheter ablation (CA) is a well-established therapy for ES. However, data regarding the impact of CA on the short-term and midterm survival of patients admitted for ES remain unclear., Objectives: This multicenter study aimed to investigate the impact of CA of ES on survival outcomes, while accounting for key patient characteristics associated with treatment selection., Methods: A propensity score-matching (PSM) analysis was performed on 780 consecutive patients admitted for ES in 4 tertiary centers. PSM (1:1) based on the main characteristics associated with the use of CA or medical therapy alone was performed, resulting in 2 groups of 288 patients., Results: After PSM, patients who underwent CA (n = 288) and those treated with medical therapy alone (n = 288) did not present any significant differences in the main demographic characteristics, ES presentation, and management. Compared with medical therapy alone, CA was associated with a significantly lower rate of ES recurrence at 1 year (5% vs 26%; P < 0.001). Similarly, CA was associated with a higher 1-year (91% vs 81%; P < 0.001) and 3-year (78% vs 71%; P = 0.017) survival after discharge. In subgroup analyses, effect of ablation therapy remained consistent in patients older than 70 years of age (HR: 0.39; 95% CI: 0.24-0.66), with substantial efficacy in patients with a LVEF <35% (HR: 0.39; 95% CI: 0.27-0.59)., Conclusions: In propensity-matched analyses, this large study shows that CA-based management of patients admitted for ES is associated with a reduction in mortality compared with medical treatment, particularly in patients with a low ejection fraction., Competing Interests: Funding Support and Author Disclosures The authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Sustained ventricular tachycardia (VT) in cardiac amyloidosis is uncommon, and the substrate and outcomes of catheter ablation are not defined., Methods: We included 22 consecutive patients (mean age, 68±10 years; male sex, 91%) with cardiac amyloidosis (ATTR [transthyretin], n=16; light chain, n=6) undergoing catheter ablation for VT/ventricular fibrillation (VF) between 2013 and 2023 in a retrospective, observational, international study. The primary efficacy outcome was recurrent VT/VF during follow-up, while the primary safety end point included major procedure-related adverse events., Results: The indication for ablation was drug-refractory VT in 17 patients (77%), and premature ventricular complex-initiated polymorphic VT/VF in 5 patients (23%). Catheter ablation was performed using endocardial (n=17.77%) or endo-epicardial approaches (n=5.23%). Complete endocardial electroanatomical voltage maps of the left and right ventricles were obtained in 17 (77%) and 10 (45%) patients, respectively. Each patient had evidence of low-voltage areas, most commonly involving the interventricular septum (n=16); late potentials were recorded in 16 patients (73%). A median of 1 (1-2) VT was inducible per patient; 12 of the 26 mappable VTs (46%) originated from the interventricular septum. Complete procedural success was achieved in 16 patients (73%), with 4 (18%) major procedure-related adverse events. After a median follow-up of 32 (14-42) months, sustained VT/VF recurrence was observed in 9 patients (41%); survival free from VT/VF recurrence was 56% (95% CI, 36%-86%) at 36-month follow-up, and most patients remained on antiarrhythmic drugs. A significant reduction in per patient implantable cardioverter defibrillator therapies was noted in the 6-month period after ablation (before: 6 [4-9] versus after: 0 [0-0]; P <0.001). In multivariable analysis, complete procedural success was associated with reduced risk of recurrent VT/VF (hazard ratio, 0.002; P =0.034)., Conclusions: Catheter ablation can achieve control of recurrent VT/VF in more than half of patients with cardiac amyloidosis, and the reduction in VT/VF burden post-ablation may be relevant for quality of life. Septal substrate and risk of procedure-related complications challenge successful management of patients with cardiac amyloidosis and VT/VF., Competing Interests: Dr Dello Russo is a consultant for Abbott Medical. Dr Stevenson has received speaking honoria from Boston Scientific, Abbott, Medtronic, Johnson and Johnson, and Biotronik. Dr Tondo receives educational, tutoring, and lecture fees from Abbott Medical, Boston Scientific, and Biosense & Webster. Dr Natale is a consultant for Biosense Webster, Abbott, Boston Scientific, Biotronik, and iRhythm. Dr Casella has received speaker honoraria from Biosense Webster. The other authors report no conflicts.

Background: Purkinje fibers play an important role in initiation and maintenance of ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Fascicular substrate modification (FSM) approaches have been suggested to treat recurrent VF in case reports and small case series., Objectives: The aim of this study was to investigate outcomes of catheter-based FSM to treat VF and PMVT., Methods: Of 2,212 consecutive patients with ventricular arrhythmia undergoing catheter ablation, 18 (0.81%) underwent FSM of the Purkinje fibers as identified with high-density mapping during sinus rhythm. Fascicular substrate and VF initiation were mapped using a multipolar catheter. The endpoint of the ablation was noninducibility of VF and PMVT. In select patients, remapping revealed elimination of the targeted Purkinje potentials. Demographic, clinical, and follow-up characteristics were prospectively collected in our institutional database., Results: A total of 18 patients (mean age 56 ± 3.8 years, 22% women) were included in the study. Of those, 11 (61.1%) had idiopathic VF, 3 (16.7%) had nonischemic cardiomyopathy, and 4 (22.2%) had mixed cardiomyopathy. The average left ventricular ejection fraction was 42.5%. At least 2 antiarrhythmic drugs had failed preablation. At baseline, all patients had inducible VF or PMVT. At the end of the procedure, no patient demonstrated new evidence of fascicular block or bundle branch block. There were no procedure-related complications. After a median follow-up period of 24 months, 16 patients (88.9%) were arrhythmia free on or off drugs: 11 of 11 patients (100%) with idiopathic VF vs 5 of 7 patients (71.4%) with underlying cardiomyopathy (P = 0.06)., Conclusions: Catheter ablation of human VF and PMVT with FSM is feasible and safe and appears highly effective, with high rates of acute VF noninducibility and long-term freedom from recurrent VF., Competing Interests: Funding Support and Author Disclosures Dr Burkhardt is a consultant for Biosense Webster and Stereotaxis. Dr Di Biase is a consultant for Biosense Webster, Stereotaxis, and I-Rhythm; and has received speaker honoraria and travel expenses from Biosense Webster, Abbott Medical, Boston Scientific, Medtronic, Biotronik, and Zoll. Dr Santangeli is a consultant for Abbott, Biosense Webster, Boston Scientific, and Medtronic. Dr Natale is a consultant for Abbott, Baylis, Biotronik, Biosense Webster, Boston Scientific, and Medtronic. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (Copyright © 2024 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.)

Background: Congenital absence of the pericardium (CAP) is a rare cardiac abnormality. As pericardial defects are usually asymptomatic, most cases are diagnosed during surgery or on autopsy. The patient in this case was found to have CAP during thoracoscope., Case: We present the unusual case of a 69-year-old patient with CAP who experienced sudden ventricular arrhythmia and developed ventricular fibrillation during left upper lobectomy. Surgical operations, the lateral decubitus position, and other external stimuli may be important risk factors for ventricular fibrillation. The patient regained sinus rhythm soon after intrathoracic cardiac compression and pharmacological treatment, including lidocaine spray (2%, 10 ml) administered to the heart surface. The surgery was then completed without any additional instances of ventricular arrhythmia., Conclusions: Patients with CAP are more susceptible to cardiac-related adverse events during thoracotomy or thoracoscopy. Treatment of ventricular arrhythmias that occur during lung resection in patients with CAP should be emphasized.

Stereotactic arrhythmia radioablation (STAR) is a treatment option for recurrent ventricular tachycardia/fibrillation (VT/VF) in patients with structural heart disease (SHD). The current and future role of STAR as viewed by cardiologists is unknown. The study aimed to assess the current role, barriers to application, and expected future role of STAR. An online survey consisting of 20 questions on baseline demographics, awareness/access, current use, and the future role of STAR was conducted. A total of 129 international participants completed the survey [mean age 43 ± 11 years, 25 (16.4%) female]. Ninety-one (59.9%) participants were electrophysiologists. Nine participants (7%) were unaware of STAR as a therapeutic option. Sixty-four (49.6%) had access to STAR, while 62 (48.1%) had treated/referred a patient for treatment. Common primary indications for STAR were recurrent VT/VF in SHD (45%), recurrent VT/VF without SHD (7.8%), or premature ventricular contraction (3.9%). Reported main advantages of STAR were efficacy in the treatment of arrhythmias not amenable to conventional treatment (49%) and non-invasive treatment approach with overall low expected acute and short-term procedural risk (23%). Most respondents have foreseen a future clinical role of STAR in the treatment of VT/VF with or without underlying SHD (72% and 75%, respectively), although only a minority expected a first-line indication for it (7% and 5%, respectively). Stereotactic arrhythmia radioablation as a novel treatment option of recurrent VT appears to gain acceptance within the cardiology community. Further trials are critical to further define efficacy, patient populations, as well as the appropriate clinical use for the treatment of VT., Competing Interests: Conflict of interest: B.K., H.I.L., and J.C. have nothing to declare. D.D. received modest lecture honorary, travel grants, and/or a fellowship grant from Abbott, AstraZeneca, Biotronik, Boehringer Ingelheim, Boston Scientific, Bristol Myers Squibb, CVRx, Medtronic, MicroPort, Pfizer, Sanofi, and Zoll. M.M. reports receiving speaker fees from Abbott, Bayer, Biosense Webster, Biotronik, Amomed, AOP Orphan, Boston Scientific, Daiichi Sankyo, and BMS/Pfizer and research grants from Biosense Webster and Abbott. A.M.S. received educational grants through his institution from Abbott, Bayer Healthcare, Biosense Webster, Biotronik, Boston Scientific, BMS/Pfizer, and Medtronic and speaker/advisory board/consulting fees from Bayer Healthcare, Biotronik, Daiichi Sankyo, Medtronic, Novartis, BMS/Pfizer, StrideBio Inc., and Zoll. P.F. reports patent applications related to bipolar and high-voltage ablation and has equity in CorSystem., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Competing Interests: Funding Support and Author Disclosures Dr Sanders is supported by a Practitioner Fellowship from the National Health and Medical Research Council of Australia, reports having served on the advisory boards of Biosense-Webster, Medtronic, Abbott, Boston Scientific, Pacemate, and CathRx, and reports that the University of Adelaide has received on his behalf lecture and/or consulting fees from Medtronic, Abbott, Boston Scientific, and Microport. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.

Aims: The aim of this study was to investigate the outcomes of catheter ablation (CA) in preventing arrhythmic events among patients with symptomatic Brugada syndrome (BrS) who declined implantable cardioverter defibrillator (ICD) implantation., Methods and Results: A total of 40 patients with symptomatic BrS were included in the study, of which 18 refused ICD implantation and underwent CA, while 22 patients received ICD implantation. The study employed substrate modification (including endocardial and epicardial approaches) and ventricular fibrillation (VF)-triggering pre-mature ventricular contraction (PVC) ablation strategies. The primary outcomes were a composite endpoint consisting of episodes of VF and sudden cardiac death during the follow-up period. The study population had a mean age of 43.8 ± 9.6 years, with 36 (90.0%) of them being male. All patients exhibited the typical Type 1 BrS electrocardiogram pattern, and 16 (40.0%) were carriers of an SCN5A mutation. The Shanghai risk scores were comparable between the CA and the ICD groups (7.05 ± 0.80 vs. 6.71 ± 0.86, P = 0.351). Ventricular fibrillation-triggering PVCs were ablated in 3 patients (16.7%), while VF substrates were ablated in 15 patients (83.3%). Epicardial ablation was performed in 12 patients (66.7%). During a median follow-up of 46.2 (17.5-73.7) months, the primary outcomes occurred more frequently in the ICD group than in the CA group (5.6 vs. 54.5%, Log-rank P = 0.012)., Conclusion: Catheter ablation is an effective alternative therapy for improving arrhythmic outcomes in patients with symptomatic BrS who decline ICD implantation. Our findings support the consideration of CA as an alternative treatment option in this population., Competing Interests: Conflict of interest: none declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: Catheter ablation of premature ventricular contractions (PVCs) that trigger polymorphic ventricular tachycardia (PVT) or ventricular fibrillation has been reported as a novel therapy to reduce the syncope events in patients with catecholaminergic PVT, whereas the long-term ablation outcome and its value in improving exercise-induced ventricular arrhythmias remain unclear., Methods and Results: Fourteen consecutive selected patients with catecholaminergic PVT (mean±SD age, 16±6 years; 43% male patients) treated with maximum β-blockers with no possibility of adding flecainide were prospectively enrolled for catheter ablation. The primary end point was syncope recurrence, and the secondary end point was the reduction of the ventricular arrhythmia score during exercise testing. Twenty-six PVT/ventricular fibrillation-triggering PVCs were identified for ablation. The trigger beats arose from the left ventricle in 50% of the cases and from both ventricles in 36% of the cases. Purkinje potentials were observed at 27% of the targets. After a mean follow-up of 49 months after ablation, 8 (57%) patients were free from syncope recurrence. Ablation of trigger beat significantly reduced the syncope frequency (mean±SD, 4.3±1.6 to 0.5±0.8 events per year; P <0.001) and improved the ventricular arrhythmia scores at the 3-month (5 [range, 3-6] to 1.5 [range, 0-5]; P =0.002) and 12-month (5 [range, 3-6] to 2 [range, 0-5]; P =0.014) follow-ups. The induction of nontriggering PVCs postablation was closely associated with syncope recurrence (hazard ratio, 6.8 [95% CI, 1.3-35.5]; P =0.026)., Conclusions: Catheter ablation of PVT/ventricular fibrillation-triggering PVCs in patients with catecholaminergic PVT who cannot receive flecainide treatment seems to be a safe and feasible adjunctive treatment that may reduce the syncope burden and improve exercise-related ventricular arrhythmias. Induction of nontriggering PVCs after ablation is associated with a higher risk of syncope recurrence.

Aims: The mechanisms of transition from regular rhythms to ventricular fibrillation (VF) are poorly understood. The concordant to discordant repolarization alternans pathway is extensively studied; however, despite its theoretical centrality, cannot guide ablation. We hypothesize that complex repolarization dynamics, i.e. oscillations in the repolarization phase of action potentials with periods over two of classic alternans, is a marker of electrically unstable substrate, and ablation of these areas has a stabilizing effect and may reduce the risk of VF. To prove the existence of higher-order periodicities in human hearts., Methods and Results: We performed optical mapping of explanted human hearts obtained from recipients of heart transplantation at the time of surgery. Signals recorded from the right ventricle endocardial surface were processed to detect global and local repolarization dynamics during rapid pacing. A statistically significant global 1:4 peak was seen in three of six hearts. Local (pixel-wise) analysis revealed the spatially heterogeneous distribution of Periods 4, 6, and 8, with the regional presence of periods greater than two in all the hearts. There was no significant correlation between the underlying restitution properties and the period of each pixel., Conclusion: We present evidence of complex higher-order periodicities and the co-existence of such regions with stable non-chaotic areas in ex vivo human hearts. We infer that the oscillation of the calcium cycling machinery is the primary mechanism of higher-order dynamics. These higher-order regions may act as niduses of instability and may provide targets for substrate-based ablation of VF., Competing Interests: Conflict of interest: None declared., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background: A novel ablation technique with guidewire has emerged as a promising approach for mapping and ablation of arrhythmias originating from left ventricular summit. However, its biophysical characteristics have not been fully clarified., Methods and Results: In the in vitro experiment, guidewire ablation (GA) was performed in vessel models of 1.17 and 2.24 mm to determine the maximum safety power. Then with the maximum safety power, the predictive value of generator impedance (GI) drop on lesion radius was explored. In the in vivo experiment, the feasibility of the maximum safety power and lesion formation was verified in the living swine. It was found that in both groups, the incidence of steam pops increased along with the raise of ablation power, and the maximum safety power was 10 W for the 1.17-mm group and 15 W for the 2.24-mm group. There was a strong linear correlation between GI drop and maximum lesion radius (in 1.17 mm-10-W group: r = .961; in 2.24 mm-15-W group: r = .918). In the in vivo experiment, besides ventricular fibrillation happened once, no other complications were observed, and lesions were found at both 48-h and 8-week groups., Conclusions: The safety power of GA should be adjusted according to the diameter of the vessel. Besides, the GI drop can predict the lesion radius during GA., (© 2023 Wiley Periodicals LLC.)

A 73-year-old woman with a history of aortitis syndrome was referred to our hospital presenting with congestive heart failure caused by acute severe mitral regurgitation due to posterior leaflet prolapse. Upon admission, the patient fell into shock state while undergoing an examination. Medical treatment including mechanical ventilation could not alleviate circulatory collapse, so emergency surgery was performed on the day of admission. Severe calcification of the ascending aorta and severe stenosis or occlusion of the aortic arch vessels resulted from the patient's aortitis syndrome precluded aortic cannulation and aortic clamp. Therefore, mitral valve repair was performed under ventricular fibrillation at moderate hypothermia. Surgery was successful, and the patient recovered well without any cerebral complications after the surgery.

Three decades have passed since the Brugada syndrome (BrS) clinical entity was introduced in the early 1990s. During the first 2 decades, treatment of patients with BrS was challenging because there were limited treatment options, and an implantable cardioverter-defibrillator was the only choice for high-risk patients with BrS, that is, those who had aborted sudden cardiac death or had previous ventricular fibrillation episodes. In this article, the authors focus on these advances and how to treat patients with BrS with catheter ablation., Competing Interests: Conflict of interest Dr R. Chokesuwattanaskul has no conflict of interest. Dr K. Nademanee has royalty income and consultant honoraria from Biosense Webster, Inc. and research grants from Biosense Webster, Inc and Medtronic Inc. Disclosure This work is partially supported by The National Research Council of Thailand and Grant-in-Aid from Bumrungrad Hospital, Bangkok, Thailand and Medtronic Inc., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Aim: Cardiac sympathetic denervation (CSD) has been introduced as a bailout therapy in patients with structural heart disease and refractory ventricular arrhythmias (VAs), but available data are scarce. Purpose of this study was to estimate immediate results, complications, and mid-term outcomes of CSD following recurrent VA after catheter ablation., Methods and Results: Adult patients who underwent CSD in the Heart Center Leipzig from March 2017 to February 2021 were retrospectively analysed. Follow-up (FU) was executed via implantable cardioverter defibrillator (ICD) interrogation, telephone interviews, and reviewing medical records. Twenty-one patients (age 63.7 ± 14.4 years, all men, 71.4% non-ischaemic cardiomyopathy, left ventricular ejection fraction 31.6 ± 12.6%) received CSD via video-assisted thoracoscopic surgery (90.5% bilateral, 9.5% left-sided only). Indication for CSD was monomorphic ventricular tachycardia in 76.2% and ventricular fibrillation in 23.8 with 71.4% of patients presenting with electrical storm before index hospitalization. Procedure-related major complications occurred in 9.5% of patients. In-hospital adverse events not related to surgery were common (28.6%) and two patients died during the index hospital stay. During FU (mean duration 9.1 ± 6.5 months), five more patients died. Of the remaining patients, 38.5 and 76.9% were free from any VA or ICD shocks, respectively., Conclusions: The CSD showed additional moderate efficacy to suppress VAs, when performed as a bailout therapy after previously unsuccessful catheter ablation. At 9 months, it was associated with freedom of ICD shocks in two-thirds of patients. In a population with many comorbidities, the rate of CSD-related complications was acceptable, although there was an overall high risk of procedure unrelated adverse events and death., Competing Interests: Conflict of interest: All authors state that there is nothing to declare., (© The Author(s) 2022. Published by Oxford University Press on behalf of the European Society of Cardiology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

A man in his 40s presented with an acute anterior wall myocardial infarction (MI) 6 hours after symptom onset to a non-percutaneous intervention enabled hospital and underwent thrombolysis with tenecteplase. His chest pain resolved post-thrombolysis although ST segment resolution was less than 50%. He had an episode of sustained ventricular tachycardia (VT) 48 hours after MI which was successfully cardioverted with 150 J biphasic shock. A month later he presented with a ventricular tachycardia storm that was refractory to pharmacological management. He underwent radiofrequency ablation of the VT using three-dimensional mapping. Although the patient remained free of VT/ventricular fibrillation (VF) for 48 hours, he had an episode of VF subsequently. A decision for bilateral surgical video assisted thoracoscopic cardiac sympathetic denervation was taken and the patient remained free of ventricular tachyarrhythmias after the procedure until., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2022. No commercial re-use. See rights and permissions. Published by BMJ.)

Objectives:  To explore the efficacy and safety of bilateral thoracoscopic cardiac sympathetic denervation (BTCSD) as an underutilised last‑resort surgical technique for patients with ventricular tachyarrhythmias and electrical storm non-responsive to other treatment., Background:  Patients with refractory ventricular tachycardia, ventricular fibrillation, and electrical storm are at high risk of sudden cardiac death. In some patients, suboptimal results are achieved despite treatment with anti-arrhythmic drugs, implantable cardioverter-defibrillator and cardiac catheter ablation. Minimally invasive surgery affecting the stellate ganglions and sympathetic chain is an additional alternative treatment modality that may help avoid heart transplantation., Methods:  We present our experience of 3 patients who were treated with this technique for the first time in Slovakia in cooperation with the National Institute for Cardiovascular Diseases. Publications on this issue are scarce despite its potential for specific patients. Modifications to avoid complications derived from our experience of sympathectomies for hyperhidrosis are introduced, and improvements are proposed to promote this technique., Results:  All patients showed a reduction or cessation of arrhythmias and ICD shocks with no periprocedural complications., Conclusion:  Our experience showed that BTCSD is a safe and feasible technique with a low complication rate and promising results. The limitation of this paper is the low number of patients in our group (Tab. 1, Fig. 3, Ref. 25).

In patients with idiopathic ventricular fibrillation (VF), recurrent implantable cardioverter-defibrillator (ICD) shocks might increase mortality risk and reduce patients' quality of life. Catheter ablation of triggering ectopic beats is considered to be an effective method. We present a patient with recurrent VF, caused by the "R on T" premature ventricular complexes. In the presented case radiofrequency catheter ablation efficiently eliminated arrhythmia trigger, which was possible to detect thanks to the intracardiac electrocardiograms (ECG's) stored in the ICD.

Background: Catheter ablation (CA) is effective for recurrent episodes of ventricular fibrillation (VF) in Brugada syndrome (BrS). VF development in BrS is associated with several electrocardiogram (ECG) abnormalities. This study investigated changes in ECG parameters in high-risk BrS patients who underwent epicardial CA., Methods and results: In all, 27 BrS patients were implanted with an implantable cardioverter-defibrillator (ICD). Patients were divided into 2 groups: (1) an ablation group (n=11) that underwent epicardial CA because of VF recurrence; and (2) a primary prevention (PP) group (n=16) with ICD implantation only. ECG parameters were evaluated before and 12 months after CA and compared with ECG parameters in the PP group. The T wave peak-to-end interval was significantly longer and the number of abnormal spikes in leads V1-V3 at the second, third, and fourth intercostal spaces was greater in the ablation than PP group. After ablation, ST levels and the sum of abnormal spikes in leads V1-V3 were significantly decreased. The mean (±SD) number of ICD shocks decreased markedly during a mean follow-up period of 42.0 months (from 3.8±3.7 to 0.2±0.4/year). Four patients had an ICD shock following the ablation procedure. Greater reductions in ST-segment elevation and abnormal spikes were observed in the group without than with VF recurrence., Conclusions: Improvements in surface ECG parameters appear to be associated with successful ablation in high-risk BrS patients.

Background: Shocks near defibrillation threshold (nDFT) strength commonly extinguish all ventricular fibrillation (VF) wavefronts, but a train of rapid, well-organized postshock activations (PAs) typically appears before sinus rhythm ensues. If one of the PA waves undergoes partial propagation block (wavebreak), reentry may be induced, causing VF to reinitiate and the shock to fail., Objective: The purpose of this study was to determine whether wavebreak leading to VF reinititation following nDFT shocks occurs preferentially at the right ventricular insertion (RVI), which previous studies have identified as a key site for wavebreak., Methods: We used panoramic optical mapping to image the ventricular epicardium of 6 isolated swine hearts during nDFT defibrillation episodes. After each experiment, the hearts were fixed and their geometry scanned with magnetic resonance imaging (MRI). The MRI and mapping datasets were spatially coregistered. For failed shocks, we identified the site of the first wavebreak of a PA wave during VF reinitiation., Results: We recorded 59 nDFT failures. In 31 of these, the first wavebreak event occurred within 1 cm of the RVI centerline, most commonly on the anterior side of the right ventricular insertion (aRVI) (23/31). The aRVI region occupies 16.8% ± 2.5% of the epicardial surface and would be expected to account for only 10 wavebreaks if they were uniformly distributed. By χ 2 analysis, aRVI wavebreaks were significantly overrepresented., Conclusion: The anterior RVI is a key site in promoting nDFT failure. Targeting this site to prevent wavebreak could convert defibrillation failure to success and improve defibrillation efficacy., (Copyright © 2021 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Purpose: Prior studies reporting efficacy of radiofrequency catheter ablation for complex ventricular ectopy in mitral valve prolapse (MVP) are limited by selective inclusion of bileaflet MVP, papillary muscle only ablation, or short-term follow-up. We sought to evaluate the long-term incidence of hemodynamically significant ventricular tachycardia (VT) or fibrillation (VF) in patients with MVP after initial ablation., Methods: We studied consecutive patients with MVP undergoing ablation for complex ventricular ectopy between 2013 and 2017 at our institution. Of 580 patients with MVP, we included 15 (2.6%, 10 women; mean age 50 ± 14 years, 53% bileaflet) with complex ventricular ectopy treated with initial ablation., Results: Over a median follow-up of 3406 (1875-6551) days or 9 years, 5 of 15 (33%) patients developed hemodynamically significant VT/VF after their initial ablation and underwent placement of an implantable cardioverter defibrillator (ICD). Three of 5 also underwent repeat ablations. Sustained VT was inducible prior to index ablation in all 5 who developed VT/VF, compared to none of the 10 patients who did not develop VT/VF after index ablation (p = 0.002). Complex ventricular ectopy at index ablation was multifocal in all 5 patients who underwent repeat intervention versus 4 of 10 patients (40%) who did not (p = 0.04). All 3 patients with subsequent VT/VF who underwent repeat ablation had a new clinically dominant focus of ventricular arrhythmia and 3 of the patients with ICD had appropriate VT/VF therapies., Conclusions: In the long term, a subset of MVP patients treated with ablation for ventricular arrhythmias, all with multifocal ectopy on initial EP study, develop hemodynamically significant VT/VF. Our findings suggest the progressive nature of ventricular arrhythmias in patients with MVP and multifocal ectopy.

Introduction: Renal sympathetic denervation (RSDN) is an alternate management approach for refractory ventricular arrhythmias (VAs). We aimed to perform a systematic review of clinical outcomes on the impact of RSDN on refractory VA patients., Methods: A systematic search without language restriction, using PubMed, EMBASE, SCOPUS, Google Scholar, and ClinicalTrials.gov from inception to August 18, 2020, was performed for the studies that reported outcomes in patients who underwent RSDN for VA. The outcomes studied were-(1) recurrent VA; and (2) all-cause mortality., Results: Five studies (from 2014 to 2018) with a total of 51 VA patients met study inclusion criteria. The mean age was 61.92 ± 11.76 years, and 78.4% were men. The pooled incidence of short-term (3 months or less) and long-term (more than 3 months) VA recurrence was 63.85% (95% CI 16.75 to 99.32) and 10.52% (95% CI 0.14 to 28.75), respectively. When stratified by the number of VA episodes, there was a significant reduction in mean VA episodes (SMD -3.79, 95% CI -6.59 to -0.98, p < .01), ICD shocks (SMD -1.71, 95% CI -3.0 to -0.42, p < .01) and anti-tachycardia pacing (SMD -1.21, 95% CI -1.98 to -0.44, p < .01) following RSDN denervation. The pooled incidence of all-cause mortality after RSDN was 10.16% (95% CI 1.08 to 24.12). There were no major vascular complications, one minor vascular complication-small non-flow limiting renal artery dissection (no intervention needed)., Conclusion: RSDN appears to be a safe and effective treatment strategy in patients with prior failed antiarrhythmic drugs and catheter ablation for recurrent ventricular arrhythmia and electrical storm., (© 2021 Wiley Periodicals LLC.)

Catheter ablation is an effective treatment method for ventricular arrhythmias (VAs). These arrhythmias can often be mapped and targeted with ablation from the left and right ventricular endocardium. However, in some situations the VA site of origin or substrate may be intramural or epicardial in nature. In these cases, the coronary venous system (CVS) provides an effective vantage point for mapping and ablation. This review highlights situations in which CVS mapping may be helpful and discusses techniques for CVS mapping and ablation., Competing Interests: The authors have completed and submitted the Methodist DeBakey Cardiovascular Journal Conflict of Interest Statement and none were reported.

Ventricular arrhythmias are potentially life-threatening disorders that are commonly treated with medications, catheter ablation and implantable cardioverter defibrillator (ICD). Adult patients who continue to be symptomatic, with frequent ventricular arrhythmia cardiac events or defibrillation from ICD despite medical treatment, are a challenging subgroup to manage. Surgical cardiac sympathetic denervation has emerged as a possible treatment option for people refractory to less invasive medical options. Recent treatment guidelines have recommendedcardiac sympathectomy for ventricular tachycardia (VT) or VT/fibrillation storm refractory to antiarrhythmic medications, long QT syndrome, and catecholaminergic polymorphic VT, with much of the data pertaining to pediatric literature. However, for the adult population, the disease indications, complications, and risks of cardiac sympathectomy are less understood, as are the most effective surgical cardiac denervation techniques for this patient demographic. This systematic review navigates available literature evaluating surgical denervation disease state indications, techniques, and sympathectomy risks for medically refractory ventricular arrhythmia in the adult patient population., Competing Interests: The authors have completed and submitted the Methodist DeBakey Cardiovascular Journal Conflict of Interest Statement and none were reported.

Catheter ablation is an established treatment strategy for ventricular arrhythmias. However, the presence of intramural substrate poses challenges with mapping and delivery of radiofrequency energy, limiting overall success of catheter ablation. Advances over the past decade have improved our understanding of intramural substrate and paved the way for innovative treatment approaches. Modifications in catheter ablation techniques and development of novel ablation technologies have led to improved clinical outcomes for patients with ventricular arrhythmias. In this review, we explore mapping techniques to identify intramural substrate and describe available radiofrequency energy delivery techniques that can improve overall success rates of catheter ablation., Competing Interests: The authors have completed and submitted the Methodist DeBakey Cardiovascular Journal Conflict of Interest Statement and none were reported.

Background: There are limited data on ventricular arrhythmias (VAs) associated with left ventricular noncompaction (LVNC) cardiomyopathy., Objectives: This study aims to analyze the clinical and electrocardiographic characteristics of VAs in a group of patients with LVNC., Methods: Forty-two nonrelated patients with LVNC and VAs were included that were evaluated at the Inherited Cardiac Disease Unit of the University Hospital Virgen Arrixaca (Murcia-Spain) (ERN Guard-Heart Centre, European Reference Network for Rare and Low Prevalence Complex Diseases of the Heart)., Results: Thirteen patients (30.9%) had isolated LVNC, 27 (64.3%) had LVNC associated with dilated cardiomyopathy, and 2 (4.8%) had LVNC associated with hypertrophic cardiomyopathy. Among isolated LVNC individuals, 9 (69.2%) had premature ventricular complexes (PVCs)/nonsustained ventricular tachycardias (VTs), and 4 (30.8%) VTs (1 VT degenerating in ventricular fibrillation). In the dilated cardiomyopathy group, 11 (40.7%) patients had PVCs, 14 (51.9%) VTs, and 2 (7.4%) ventricular fibrillation. In the hypertrophic cardiomyopathy group, one patient had PVCs and the other VTs. Endocardial mapping and ablation were performed in 19 patients (45.2%): 7 ventricular outflow tracts (4 right ventricular outflow tract, 1 left coronary cusp, and 2 right coronary cusp), 2 in the left ventricular summit, 5 related to Purkinje potentials at the mid inferoseptal area, and 5 associated with endocardial scar localized in the basal anterolateral and inferolateral segments. Epicardial ablation was performed in 3 cases., Conclusion: The substrate of VAs in LVNC cardiomyopathy is heterogeneous, with origin in ventricular outflow tracts, Purkinje system related, and resembling scar patterns in nonischemic cardiomyopathy., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

[Figure: see text].

Early repolarization syndrome is associated with an increased risk of arrhythmic death caused by ventricular fibrillation (VF). VF is usually initiated by premature ventricular contractions (PVCs), and PVCs commonly arise from Purkinje system, the ventricular outflow tract, and papillary muscles. We report the case of a patient with J wave syndromes and recurrent VF, triggered by PVCs originating from the tricuspid annular region. VF was successfully suppressed by catheter ablation of the triggering PVCs, and there has been no recurrence of VF during a follow-up period of 6 months., (© 2020 The Authors. Annals of Noninvasive Electrocardiology published by Wiley Periodicals LLC.)

Background: Studies of ventricular fibrillation (VF) in humans are limited because of the short available duration. We sought to study surface ECG waveforms and effect of ablation in long-lasting VF in patients with left assist devices., Methods: Continuous 12-lead ECG of 5 episodes of long-lasting VF occurring in 3 patients with left ventricular assist device were analyzed. Spectral analysis (dominant frequency) and quantification of waveform amplitude, regularity (Unbiased Regularity Index), and complexity (Nondipolar Index) were performed over a median of 24 minutes of VF. Radiofrequency ablation was performed during VF in 2 patients., Results: There was a significant increase in dominant frequency between VF onset and termination but none of the other parameters significantly changed. Some VF parameters varied from patient to patient and from lead to lead. Dominant frequency decreased after radiofrequency ablation in both cases and VF terminated spontaneously shortly after ablation in one case. The previously incessant VFs in these 2 patients did not recur afterward., Conclusions: VF rate increases over time in patients with left ventricular assist devices and is lowered by ablation. Long-lasting VF may be modified or even terminated by ablation.

Stereotactic cardiac radiation for ablation (radioablation) of life-threatening ventricular arrhythmia was recently introduced into clinical practice. A 76-year-old male patient with apical hypertrophic cardiomyopathy at burnout stage, who received defibrillator implantation for the secondary prevention of sudden arrhythmic death, was admitted for repeated defibrillator therapy. Radiofrequency catheter ablation was unsuccessful due to the induction of ventricular fibrillation (VF) and hemodynamically unstable sustained monomorphic ventricular tachycardia (VT). However, intracardiac activation mapping for the induced VT revealed the earliest ventricular activation at the apical aneurysm. Radioablation was performed to control VT and VF storm refractory to antiarrhythmic drug therapy. A total of 24 Gray was radiated, divided into three fractions around the apical aneurysm. The onset of electrical modulation was instantaneous and the antiarrhythmic effect was maintained for at least 6 months without significant radiation toxicities. This case suggests that radioablation may be considered as a rescue therapy for VT and VF storm refractory to other treatment modalities., Competing Interests: The authors have no potential conflicts of interest to disclose., (© 2020 The Korean Academy of Medical Sciences.)

Differentiation of outflow tract ventricular arrhythmias (OT-VAs) which originate from the posterior right ventricular outflow tract (RVOT), right coronary cusp (RCC) or near the His-bundle are still a challenge until now. This study was aimed to develop a stepwise electrocardiogram (ECG) algorithm to distinguish their locations. Seventy-five consecutive patients with VAs successfully ablated from the posterior RVOT (n = 57), near the His-bundle (n = 5) or RCC (n = 13) were enrolled in our study. Measurements with highest diagnostic performance were chosen to develop a diagnostic algorithm. Of all these ECG measurements, the R-wave amplitude in lead I and V2S/V3R index showed the best diagnostic performance to discriminate these anatomical sites. The optimal ECG discriminators were different combination of lead I and V2S/V3R index as follows: the posterior RVOT, Lead I R-wave amplitude <0.65 mV and V2S/V3R index>1.5 (96.2% sensitivity, 69.6% specificity); the near the His-bundle, lead I R-wave amplitude ≥0.65 mV and V2S/V3R index>1.5 (100% sensitivity, 70% specificity); RCC, lead I R-wave amplitude<0.65 mV and V2S/V3R index ≤1.5 (52.9% sensitivity, 93.1% specificity). Sequential algorithmic application of these criteria resulted in an overall accuracy of 83% in predicting site of OT-VA origin. A predominantly positive R-wave in lead I is seen in OT-VAs originated near the His-bundle. A stepwise ECG algorithm of combination with R-wave amplitude in lead I and V2S/V3R index could localize the origins of OT-VAs from the posterior RVOT, near the His-bundle and the RCC with a high accuracy., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Left ventricular assist devices (LVADs) are currently used as destination therapy or bridge to heart transplantation in patients with advanced chronic heart failure (CHF). It has been proved to reduce mortality and symptoms in these patients. Patients with advanced CHF are known to have increased risk of ventricular arrhythmias (ventricular tachycardia or ventricular fibrillation (VF)) despite the presence of LVAD. We report the case of patients with ongoing VF during LVAD treatment while being awake and aware. We discuss the challenges introduced along with the increasing use of LVAD treatment. The decision whether a patient with LVAD automatically should have an implantable cardioverter-defibrillator is challenging. Randomised trials are warranted to shed light on these challenging decisions., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: The management of refractory electrical storm (ES) requiring mechanical circulation support (MCS) remains a clinical challenge in structural heart disease (SHD)., Objective: The study sought to explore the 30-day and 1-year outcome of rescue ablation for refractory ES requiring MCS in SHD., Methods: A total of 81 patients (mean age: 55.3 ± 18.9, 73 men [90.1%]) undergoing ablation were investigated, including 26 patients with ES requiring MCS (group 1) and 55 patients without (group 2). The 30-day and 1-year outcome, including mortality and recurrent ventricular tachyarrhythmias (VAs) receiving appropriate implantable cardioverter defibrillators therapies, were assessed., Results: The patients in group 1 were characterized by older age, more ischemic cardiomyopathies, worse left ventricular ejection fraction, and more comorbidities. Thirty days after ablation, overall events were seen in 15 patients (mortality in 10 and recurrent VA in 7), including pumping failure-related mortality in 6 (60%). During a 30-day follow-up, higher mortality was noted in group 1. After a 1-year follow-up, in spite of the higher mortality in group 1 (P < .001), the overall events and VA recurrences were similar between these two groups (P = .154 and P = .466, respectively). There was a significant reduction of VA burden in both groups and two patients had recurrent ES., Conclusion: Higher 30-day mortality was observed in patients undergoing rescue ablation for refractory ES requiring MCS, and pumping failure was the major cause of periprocedural death. Rescue ablation successfully prevented VA recurrences and resulted in a comparable 1-year prognosis between ES with and without MCS., (© 2019 Wiley Periodicals, Inc.)

Introducción Y Objetivos: La tormenta eléctrica (TE) se caracteriza por episodios repetidos de taquicardia ventricular o fibrilación ventricular relacionados con mal pronóstico a corto y largo plazos. El objetivo fue evaluar la prevalencia, resultados y supervivencia de los pacientes sometidos a tratamiento intervencionista por TE en un centro de referencia., Métodos: Estudio unicéntrico, observacional y retrospectivo. Se revisaron los procedimientos de ablación por TE y se evaluaron las características basales de los pacientes, tipo de procedimiento, mortalidad total, recurrencia de arritmia, mortalidad cardiovascular y necesidad de trasplante., Resultados: Desde enero de 2009 hasta diciembre de 2016 se realizaron 67 procedimientos (38% de complejos: 19% de ablación endoepicárdica, 7.5% de crioablación epicárdica quirúrgica, 3% de simpatectomía, 3% de inyección coronaria con alcohol; 6% de apoyo con oxigenación con membrana extracorpórea) en 41 pacientes (61% de causa isquémica) por TE. La mortalidad intraprocedimiento fue del 1.5%. La mediana de seguimiento fue de 23.5 meses (RIQ, 14.2-52.7). Tras el primer ingreso por TE (uno o varios procedimientos), la mortalidad a un año fue de 9.8%. La incidencia acumulada de trasplante cardiaco por TE fue de 2.4%. En el análisis multivariado, el riesgo de recurrencias arrítmicas o muerte por cualquier causa fue significativamente mayor en pacientes con arritmias clínicas inducibles (HR, 9.03; p = 0.017)., Conclusiones: El tratamiento de pacientes con TE, instituido en un centro de referencia y con experiencia, se relacionó con una tasa baja de recurrencia y supervivencia elevada, con una tasa de trasplante cardiaco por TE muy baja. Ante una recurrencia temprana es recomendable practicar un nuevo procedimiento durante el ingreso., Introduction and Objective: Electrical storm (ES) is characterized by repeated episodes of ventricular tachycardia or ventricular fibrillation, with poor short and long term prognosis. Our objective was to evaluate the prevalence, results of interventional treatment and survival of patients undergoing interventional treatment for ES in our center., Methods: Retrospective, unicentric and observational study. ES ablation procedures were revised and data regarding baseline characteristics of the patients, type of procedure, total mortality, recurrence of arrhythmia, cardiovascular mortality and the need for transplantation were evaluated., Results: From January 2009 to December 2016, 67 procedures (38% complex procedures: 19% epicardial ablation, 7.5% surgical epicardial crioablation, 3% simpatectomy, 3% coronary alcohol injection, 6% extracorporeal membrane oxygenation support) were performed in 41 patients (61% Ischemic etiology) due to ES. Intraprocedural mortality was 1.5%. The median follow-up was 23.5 months (IQR [14.2-52.7]). After the first admission for ES (one or several procedures), 1-year mortality was 9.8%. The cumulative incidence of cardiac transplantation was 2.4%. The risk of arrhythmic recurrences or death was significantly higher in patients with inducible clinical arrhythmias after ablation (HR: 9.03, p = 0.017)., Conclusions: The treatment of patients with ES, performed in a reference center, allows obtaining good rates of recurrence and survival, with very low rates of cardiac transplantation for ES. In the presence of an early recurrence, it is advisable to perform a new procedure during admission., (Copyright: © 2020 Permanyer.)

The purpose of this study was to define the mechanism by which cardiac neuraxial decentralization or spinal cord stimulation (SCS) reduces ischemia-induced ventricular fibrillation (VF). Direct measurements of norepinephrine (NE) levels in the left ventricular interstitial fluid (ISF) by microdialysis, in response to transient (15-minute) coronary artery occlusion (CAO), were performed in anesthetized canines. Responses were studied in animals with intact neuraxes and were compared with those in which the intrathoracic component of the cardiac neuraxes (stellate ganglia) or the intrinsic cardiac neuronal (ICN) system was surgically delinked from the central nervous system and those with intact neuraxes with preemptive SCS (T1-T3). With intact neuraxes, animals with exaggerated NE release due to CAO were at increased risk for VF. During CAO, there was a 152% increase in NE when the neuraxes were intact compared with 114% following stellate decentralization and 16% following ICN decentralization. During SCS, CAO NE levels increased by 59%. Risk for CAO-induced VF was 38% in controls, 8% following decentralization, and 11% following SCS. These data indicate that ischemia-related afferent neuronal transmission differentially engages central and intrathoracic sympathetic reflexes and amplifies sympathoexcitation. Differences in regional ventricular NE release are associated with increased risk for VF. Surgical decentralization or SCS reduced NE release and VF.

Background: Various strategies for ablation of ventricular tachycardia (VT) have been described, but their impact on ventricular fibrillation (VF) is largely unknown. The aim of our study was to assess the effect of substrate-based VT ablation targeting local abnormal ventricular activity (LAVA) on recurrent VF events in patients with structural heart disease., Methods: A retrospective 2-center study was performed on patients with structural heart disease and both VT and VF, with incident VT ablation procedures targeting LAVAs. Generalized estimating equations with a Poisson loglinear model were used to assess the impact of catheter ablation on VF episodes. The change in VF events before and after catheter ablation was compared with matched controls without ablation., Results: From a total of 686 patients with an incident VT ablation procedure targeting LAVAs, 21 patients (age, 57±14 years; left ventricular ejection fraction, 30±10%) had both VT and VF and met inclusion criteria. A total of 80 VF events were recorded in the implantable cardioverter-defibrillator logs the 6 months preceding ablation. Complete and partial LAVA elimination was achieved in 11 (52%) and 10 (48%) patients, respectively. Catheter ablation was associated with a highly significant reduction in VF recurrences ( P <0.0001), which were limited to 3 (14%) patients at 6 months. The total number of VF events thereby decreased from 80 to 3, from a median of 1.0 (range, 1-29) to 0.0 (range, 0-1) in the 6 months before and after ablation, respectively. The reduction in VF events was significantly greater in patients with catheter ablation compared with 21 matched controls during 6-month periods following and preceding a baseline assessment (Poisson β-coefficient, 1.39; P =0.0003)., Conclusions: Substrate-guided VT ablation targeting LAVAs may be associated with a significant reduction in recurrent VF, suggesting that VT and VF share overlapping arrhythmogenic substrates in patients with structural heart disease.

Background: The definition of electrical storm is still debated. For example, an electrical storm is defined as a clustering of three or more separate episodes of ventricular tachycardia/ventricular fibrillation within 24 hours or one or more episodes occurring within 5 minutes of termination of the previous episode of ventricular tachycardia/ventricular fibrillation. When it is refractory to medications, prompt assessments by coronary angiography, sedation, and overdrive pacing should be performed. An electrical storm may occur anytime, including at night or after the patient leaves an intensive care unit., Case Presentation: A 70-year-old Japanese man with type 2 diabetes mellitus was diagnosed as having ST-elevation myocardial infarction. His clinical course after an urgent percutaneous coronary intervention was uneventful, but he developed electrical storm that was refractory to antiarrhythmic medications on day 11 of hospitalization. We used sedative medications and performed ventricular overdrive pacing and transferred him to a university hospital for further treatment, which included electrical ablation and cardioverter-defibrillator implantation., Conclusion: An electrical storm is a relatively rare and fatal complication of acute myocardial infarction. It is important that the treatment choices for this condition are known by non-cardiologist physicians who might encounter this rare condition.

Despite a 2% to 3% prevalence of echocardiographically defined mitral valve prolapse (MVP) in the general population, the actual burden, risk stratification, and treatment of the so-called arrhythmic MVP are unknown. The clinical profile is characterized by a patient, usually female, with mostly bileaflet myxomatous disease, mid-systolic click, repolarization abnormalities in the inferior leads, and complex ventricular arrhythmias with polymorphic/right bundle branch block morphology, without significant regurgitation. Among the various pathophysiologic mechanisms of electrical instability, left ventricular fibrosis in the papillary muscles and inferobasal wall, mitral annulus disjunction, and systolic curling have been recently described by pathological and cardiac magnetic resonance studies in sudden death victims and patients with arrhythmic MVP. In addition, premature ventricular beats arising from the Purkinje tissue as ventricular fibrillation triggers have been documented by electrophysiologic studies in MVP patients with aborted sudden death. The genesis of malignant ventricular arrhythmias in MVP probably recognizes the combination of the substrate (regional myocardial hypertrophy and fibrosis, Purkinje fibers) and the trigger (mechanical stretch) eliciting premature ventricular beats because of a primary morphofunctional abnormality of the mitral valve annulus. The main clinical challenge is how to identify patients with arrhythmic MVP (which imaging technique and in which patient) and how to treat them to prevent sudden death. Thus, there is a necessity for prospective multicenter studies focusing on the prognostic role of cardiac magnetic resonance and electrophysiologic studies and on the therapeutic efficacy of targeted catheter ablation and mitral valve surgery in reducing the risk of life-threatening arrhythmias, as well as the role of implantable cardioverter defibrillators for primary prevention.

Introduction: Catheter ablation is an important treatment option for sustained ventricular arrhythmias (VA) that are refractory to pharmacological treatment; however, patients with fast VA or electrical storm (ES) are at risk for cardiogenic shock. We report our experience using cardiopulmonary support with extracorporeal membrane oxygenation (ECMO) during catheter ablation of VA., Methods: Nineteen patients (mean age, 62 ± 10 years; 84% male) were referred to our center for CA of ES between January 2017 and April 2018. ES was defined as the occurrence of ≥3 ventricular tachycardia or ventricular fibrillation episodes requiring electrical cardioversion or defibrillation in a 24-hour period. ECMO support was implemented for all patients., Results: CA of ES was completed in all patients. Activation mapping was performed for all VTs and substrate modification was performed by targeting sites identified by late/fragmented abnormal potentials. VTs were not inducible after ablation in 16 of 19 patients (84%). With regard to procedural complications, two patients underwent percutaneous angioplasty with stenting for a femoral artery dissection and one patient was treated for a dislodged ECMO arterial cannula and subsequent hemorrhagic shock. After a median follow-up of 10 months, three patients died from refractory heart failure and one patient died as a result of ES. Overall, the procedural success rate was 68% and the Kaplan-Meier mortality rate was 21%., Conclusions: ECMO support may be used for ablation procedures in patients with ES., (© 2019 Wiley Periodicals, Inc.)

Background: Catheter ablation for polymorphic ventricular tachycardia and ventricular fibrillation (PMVT/VF) may target triggering premature ventricular contractions (PVCs). Targeting ventricular scar has also been suggested, but data are limited., Objective: The purpose of this study was to characterize the electrophysiological findings and ablation outcomes for patients with PMVT/VF and structural heart disease (SHD) compared to those with idiopathic VF., Methods: Data from 32 consecutive patients (13 idiopathic VF, 19 SHD) with recurrent PMVT/VF who underwent catheter ablation were reviewed., Results: A low-voltage area of myocardial scar was present in 15 of 19 patients with SHD. Sustained monomorphic ventricular tachycardia (SMVT) associated with scar was inducible and targeted in 8, 3 of whom had previous SMVT episodes separate from PMVT/VF episodes and 5 had no history of SMVT. Triggering PVCs were identified in 11 patients and arose from an area of endocardial scar in 6. Only scar ablation was performed in 8 patients who did not have triggering PVCs. All idiopathic VF patients underwent PVC ablation only. During a median of 540 days, 74% of SHD patients and 77% of idiopathic VF patients were free of recurrence, including 75% of those with only PVC ablation, 86% of those with scar plus PVC ablation, and 63% of those with only scar ablation., Conclusion: Patients with recurrent PMVT/VF and SHD often have a low-voltage scar associated with PVCs or inducible SMVT, which may also be the substrate for PMVT/VF. When present, substrate ablation targeting scar is a reasonable option for treatment of PMVT/VF even if PVCs are absent., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)