Recurrent Ventricular Arrhythmias Research Articles

Optical control of cardiac electrophysiology by the photochromic ligand azobupivacaine 2.

Patients suffering from ischaemic heart disease and heart failure are at high risk of recurrent ventricular arrhythmias (VAs), eventually leading to sudden cardiac death. While high-voltage shocks delivered by an implantable defibrillator may prevent sudden cardiac death, these interventions themselves impair quality of life and raise both morbidity and mortality, which accentuates the need for developing novel defibrillation techniques. Photopharmacology allows for reversible control of biological processes by light. When relying on synthetic and externally applied chromophores, it renders genetic modification of target cells dispensable and may hence be advantageous over optogenetic approaches. Here, the photochromic ligand azobupivacaine 2 (AB2) was probed as a modulator of cardiac electrophysiology in an ex vivo intact mouse heart model. By reversibly blocking voltage-gated Na+ and K+ channels, photoswitching of AB2 modulated both the ventricular effective refractory period and the conduction velocity in native heart tissue. Moreover, photoswitching of AB2 was able to convert VA into sinus rhythm. The present study provides the first proof of concept that AB2 enables gradual control of cardiac electrophysiology by light. AB2 may hence open the door to the development of an optical defibrillator based on photopharmacology.

Abstract 4148089: Comparative Efficacy of Carvedilol versus Metoprolol in Patients with Implantable Cardioverter Defibrillators and Ventricular Arrhythmias: A Systematic Review and Meta-Analysis

Background: Ventricular arrhythmias are major causes of morbidity and mortality in patients with cardiovascular disease. Implantable cardioverter-defibrillators (ICDs) are commonly used to prevent sudden cardiac death in these patients. However, patients with ICDs frequently experience recurrent arrhythmias and inappropriate shocks, which can impact their quality of life. Beta-blockers, specifically carvedilol and metoprolol, are commonly prescribed to manage these arrhythmias. This meta-analysis aims to compare the impact of both medications in this patient population. Methods: A comprehensive literature search was conducted to identify relevant studies comparing carvedilol to metoprolol in patients with ventricular arrhythmias or ICDs. Study outcomes included all-cause mortality, recurrent ventricular arrhythmia, and inappropriate ICD shocks. Effect estimates are presented as hazard ratios (HR) with 95% confidence intervals (CI). Results: 1,453 studies were identified through database search. After full-text screening, a total of 5 studies involving 9,292 patients were included. We found no significant difference in the incidence of recurrent ventricular arrhythmias between carvedilol and metoprolol (HR = 0.99, 95% CI [0.75, 1.32], P = 0.97). Additionally, Carvedilol showed a trend toward reduction of all-cause mortality (HR = 0.83, 95% CI [0.68, 1.03], P = 0.09). On the other hand, Carvedilol was associated with a statistically significant reduction of inappropriate ICD shocks (HR = 0.61, 95% CI [0.48, 0.78], P < 0.001). Conclusion: Carvedilol may offer additional benefits over metoprolol in managing patients with ventricular arrhythmias or ICDs, particularly in minimizing the incidence of inappropriate ICD shocks. However, no significant difference was found in terms of all-cause mortality and recurrent ventricular arrhythmia incidence. Further research is needed to confirm these findings and guide clinical decision-making.

Abstract 4117406: The Safety and Efficacy of Surgical Cardiac Sympathetic Denervation for Ventricular Arrhythmias: An Updated Systematic Review&Meta-Analysis

Objectives: This meta-analysis sought to explore the long-term arrhythmic outcomes of cardiac sympathetic denervation (CS) by measuring event rates of recurrent ventricular arrhythmias (VA) and implantable cardiac defibrillator shocks (ICD) post CSD. Background: The role of sympathetic nervous system in the beginning and continuation of ventricular arrhythmias (VAs) is well known. CS has been associated with improved arrhythmic outcomes in patients with refractory ventricular arrhythmias. However, whether CSD lowers shock event rates after the procedure is still uncertain and therefore, we performed a systematic review and meta-analysis to evaluate this. Methods&Materials: A comprehensive literature search was performed at Medline and Embase until March 2023. Our primary outcome was event rate of ICD shocks at 30 days, 90 days, and 1 year following CS. All analysis was conducted using Comprehensive Meta-Analysis software. Results: The initial search found 1,324 articles. After all articles were examined, a total of 29 studies fit our criteria. ICD shocks 1 year post CSD had a pooled event rate of 66.5% with a 95% confidence interval (CI) of 57.7% to 74.3% and the I-squared (I2) statistics. ICD shocks at 6 months had an event rate at 61.7% with a 95% confidence interval of 53.3% to 69.4% with I2 at 46. VA in one year post CSD had a pooled event rate of 62.5 with a 95% with a CI of 53.3% to 69.1% and I2 at 22%. At 6 months the event rate was 64.2 with a 95% CI of 56.3% to 71.4% with I2 at 33% Mortality from cardiac arrhythmia and classified 0-30 days (short term), 21-364 days (medium term), and >365 days (long term). The pooled event rate for short term morality was 6.8% with a 95% CI of 4.2%-11.0% with I2 at 0%, medium term was 5.2% with a 95% CI of 2.9% to 8.9% with I2 at 0%, and long term was 5.0% with a 95% CI of 2.7% to 9.2% and I2 at 0%. Conclusion: CSD may be an alternative form of therapy that reduces shock event rates and recurrent VA in patients that are refractory to ablation and medical therapy. However larger prospective studies are needed to further evaluate the usefulness and safety of CSD.

Incidence of ventricular arrhythmias after implantable cardioverter-defibrillator implantation or replacement, and driving restriction consequences

BackgroundFollowing implantation/replacement of an implantable cardioverter-defibrillator, patients are legally subjected to variable lengths of driving restrictions based on the indication (1 and 3 months after primary and secondary prevention, respectively; 1 week after device replacement). AimTo assess the incidence of ventricular arrhythmia during the theoretical driving restriction period in a large cohort of patients. MethodsPatients who underwent implantable cardioverter-defibrillator implantation for primary or secondary prevention or device replacement between 2015 and 2021 were included retrospectively. The primary endpoint was the occurrence of ventricular arrhythmia during the theoretical driving restriction period, as defined by guidelines. ResultsA total of 914 patients were analysed, including 654 first implantations (438 and 216 for primary and secondary prevention, respectively) and 260 device replacements. The primary outcome occurred in 2/438 patients (0.004%) during the 1-month period following device implantation for primary prevention and in 25/216 patients (11.5%) during the 3-month period following device implantation for secondary prevention; it did not occur in the 1-week period following device replacement. The monthly calculated risk of harm remained below the accepted threshold of 0.005% for each group. ConclusionsPrimary prevention patients, such as those who have undergone device replacement, have a low risk of ventricular arrhythmia, which could lead to a reduction in their driving restriction period. Secondary prevention patients experienced a higher risk of recurrent ventricular arrhythmia, supporting the 3-month driving restriction period.

Comparison of ventricular tachyarrhythmias in HF patients on dapagliflozin versus empagliflozin

Abstract Background Ventricular tachycardia (VT) and ventricular fibrillation (VF) are devastating tachyarrhythmias that can cause sudden cardiac death in patients with heart failure (HF) if not anticipated or treated promptly. Although post-hoc analysis in DAPA-HF showed promise in their benefit, Sodium-glucose transport protein 2 inhibitors (SGLT2i) have not yet been evaluated for their effect on these tachyarrhythmias. This retrospective analysis aims to compare the 2 most commonly used SGLT2i agents, dapagliflozin and empagliflozin, and the incidence of VT in patients with HF. Methods The TriNetX Research network was used for this study. The two initial patient cohorts were created using ICD-10 codes and medication codes from the TriNetX platform. Both cohorts consisted of patients over age 60 with a history of heart failure and either VF or VT. One cohort was on treatment with dapagliflozin and the other with empagliflozin. The cohorts were balanced by propensity score matching and the greedy nearest neighbor algorithm for age, gender, race, ethnicity, hyperkalemia, and the current use of spironolactone, amiodarone, metoprolol, and carvedilol, resulting in 9,841 patients in each arm. The cohorts were then evaluated for the development of VF or VT over the subsequent five years as well as all-cause mortality. Additional cohorts were created to evaluate dapagliflozin vs empagliflozin in diabetics, nondiabetics, and patients with ejection fractions less than 35% Results Dapagliflozin was associated with an increased risk of ventricular arrhythmia in heart failure patients compared to empagliflozin (46.0% vs. 40.8%, RR 1.13, 95% CI (1.09,1.16), P value < 0.0001). It was also associated with higher mortality at five years (RR 1.10, 95% CI (1.03,1.18), P value 0.0034). Conclusions In comparisons between dapagliflozin and empagliflozin in heart failure patients with previously documented ventricular arrhythmias, empagliflozin had 13% less risk of recurrence of ventricular arrhythmias. Secondarily, the empagliflozin cohort also exhibited lower all-cause mortality (14.8% vs 16.3%) at five years from starting the drug. Our analysis does not disprove findings in DAPA-HF, but rather may support the potential class effect of SGLT2 inhibitors in their ability to suppress VT.(1) Importantly, the overall incidence of ventricular tachyarrhythmias is high in both cohort, given we selected a high-risk population. Notably, our documented recurrence rate is similar to past reports of recurrence after VT ablation, the gold standard for treatment of VT. (2) SGLT2 inhibitors have shown clear benefit in multiple placebo-controlled studies in terms of heart failure outcomes like mortality and readmission, but their effect on arrhythmias is one more additional benefit this class may have. (3) Given these associations, empagliflozin may be a more favorable options for HF patients who have already had VT or VF.

Ventricular arrhythmia characteristics after left ventricular assist device implantation

Abstract Background Ventricular arrhythmia (VA) characteristics in patients with advanced heart failure (HF) and left ventricular assist devices (LVADs) are currently poorly studied. Methods Patients with advanced HF implanted with third-generation LVADs during 2019-2023 were enrolled, and six-month post-LVAD VA events were retrospectively analyzed. Baseline characteristics, 6-month VA events, Holter monitoring and ambulatory blood pressure were also analyzed. Post-LVAD VA events were categorized as new right bundle-branch block (RBBB) superiorly directed VA and prior VA recurrence. Results Fifty-four advanced HF patients (90.7% male, 50.0±13.7 years old) who underwent LVAD (CH-VAD: n=23; Evaheart2: n=10; Corheart6: n=21) were consecutively enrolled in this study. Twenty-two patients suffered post-LVAD VA events (15 new RBBB superiorly directed VA, 7 prior VA recurrence), and 94.4% of the patients were hemodynamically stable. A total of 46.3% of the patients presented with a 50% reduction in VA burden, and amiodarone use decreased from 25.9% to 16.7%. The nighttime mean arterial pressure (MAP) and maximum inferior venous cava (IVC) diameter had opposite predictive effects on the new RBBB VA, and the post-LVAD left ventricular ejection fraction (LVEF) was negatively correlated with the prior VA recurrence. Multivariate analysis revealed that a higher nighttime MAP/IVC ratio (OR 2.24, 95% CI 2.22-4.52; P=0.025) and a lower post-LVAD LVEF (OR 0.75, 95% CI 0.57-0.99; P=0.048) were independently related to the new RBBB superiorly directed VA and prior VA recurrence, respectively. Conclusion The overall VA burden decreased after LVAD implantation. Volume deficiency and poor post-LVAD cardiac function were associated with different VA patterns.Changes in VAs pre- and 6 monthsVA distributions of patients

Preliminary results of the non-invasive cardiac radioablation for ventricular tachycardia study; an in silico dosimetric comparison of photon vs proton radiotherapy for ventricular arrhythmias

Abstract Background Stereotactic arrhythmia radio-ablation (STAR) has been proposed as an alternative treatment for refractory ventricular arrhythmias (VA) in patients who are unsuitable or refractory to standard catheter ablation (CA). It consists in the application of external beam radiotherapy in a single dose of 25 Gy to the target areas. Most of the STAR treatments performed so far used photon radiotherapy. As compared to photons, particle therapy with protons, based on its finite penetration depth in tissue, might have the potential to reduce the dose to surrounding healthy tissues thus lowering the risk of side effects. Purpose The purpose of this in silico simulation study was to evaluate the feasibility of STAR with protons in patients with VA and to compare the doses of the organs at risk (OARs) in photon and proton treatment plans. Methods 14 patients (11 males) candidates to standard CA for VA were enrolled. ECG gated CT scans in expiratory breath-hold, and standard electroanatomical mapping were performed in each patients to reconstruct a 3D bipolar voltage map and identify the ablation target. Based on the information obtained by the contouring of the ablation target three treatment plans were simulated: one with photons, and two with protons - with and without cardiac gating- to assess the doses at the OARs. Results The median age was 68.5 (63.25-71.5), all patients had a history of recurrent VA and the indication for treatment with CA. 7 patients had an ischemic cardiomyopathy, 4 an idiopathic cardiomyopathy and 3 ventricular ectopic beats without structural heart disease. The mean left ventricular ejection fraction was 40±11% and 8 out of 14 patients were ICD carriers. Both photons and protons treatment plans reached the goals for target coverage (25 Gy on 98% of the target volume). A statistically significant reduction in the mean maximum dose (Dmax) to some OARs was observed in proton compared to photon plans (see table 1). Specifically, the Dmax delivered to the mitral valve, vena cava, descending aorta, esophagus and to the lungs have been largely reduced with the proton plans. However, in some specific cases, a higher maximum dose was observed for protons in structures close or overlapping with the target, mainly due to the need of an additional margin in the treatment plan to account for proton range uncertainty. The use of cardiac gating did not show a significant dose reduction to OARs compared to the non-gated proton plan. Conclusion The preliminary results of our in silico simulation study suggest that STAR therapy with the use of protons might be associated with a significant dose reduction to the surrounding organs. Nevertheless, the choice of the best treatment should be evaluated on a case by-case strategy since some specific cases may be better suitable for photon treatment.Table 1

Efficacy of stellate ganglion block in treatment of electrical storm: a systematic review and meta-analysis.

Electrical storm (ES) is a life-threatening condition of recurrent ventricular arrhythmias (VA) in a short period of time. Percutaneous stellate ganglion blockade (SGB) is frequently used - however the efficacy is undefined. The objective of our systematic review was to determine the efficacy of SGB in reducing VA events and mortality among patients with ES. A search of Medline, EMBASE, Scopus, CINAHL and CENTRAL was performed on February 29,2024 to include studies with adult patients (≥ 18 years) with ES treated with SGB. Our outcomes of interest were VA burden pre- and post-SGB, and in-hospital/30-day mortality. A total of 553 ES episodes in 542 patients from 15 observational studies were included. Treated VAs pre- and post-SGB were pooled from eight studies including 383 patients and demonstrated a decrease from 3.5 (IQR 2.25-7.25) to 0 (IQR 0-0) events (p = 0.008). Complete resolution after SGB occurred in 190 of 294 patients (64.6%). Despite this, in-hospital or 30-day mortality remained high occurring in 140 of 527 patients (random effects prevalence 22%). Repeat SGB for recurrent VAs was performed in 132 of 490 patients (random effects prevalence 21%). In conclusion, observational data suggests SGB may be effective in reducing VAs in ES. Definitive studies for SGB in VA management are needed.Study protocol: PROSPERO - registration number CRD42023430031.

Comparison of Oral Procainamide and Mexiletine Treatment of Recurrent and Refractory Ventricular Tachyarrhythmias

Background: Antiarrhythmic therapy for recurrent ventricular arrhythmias (VAs) in patients having undergone catheter ablation and in whom amiodarone and/or beta-blockers were ineffective or contraindicated is a controversial issue. Purpose: The present study sought to compare the efficacy and tolerability of oral procainamide and mexiletine in patients with recurrent ventricular arrhythmias when the standard therapy strategy failed. Methods: All patients with an implantable cardioverter defibrillator (ICD) treated with oral procainamide or mexiletine for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) in two cardiology divisions between January 2010 and January 2020 were enrolled. Patients were divided into group A (oral procainamide) and group B (mexiletine) and the two groups were compared to each other. The primary endpoint was the efficacy of therapy; the secondary endpoint was the discontinuation of therapy. All events that occurred during procainamide or mexiletine treatment were compared with a matched duration period before the initiation of the therapy. Antiarrhythmic therapy was considered effective when a ≥80% reduction of the sustained ventricular arrhythmias burden recorded by the ICD was achieved. Results: A total of 68 consecutive patients (61 males, 89.7%; mean age 74 ± 10 years) were included in this retrospective analysis. After a median follow-up of 19 months, 38 (56%) patients had a significant reduction in the VA burden. After multivariable adjustment, therapy with procainamide was independently associated with an almost 3-fold higher efficacy on VA suppression compared to mexiletine (HR 2.54, 95% CI 1.06–6.14, p = 0.03). Only three patients (9%) treated with procainamide presented severe side effects (dyspnea or hypotension) requiring discontinuation of therapy compared with six patients (18%) treated with mexiletine who interrupted therapy because of severe side effects (p = 0.47). Conclusions: Compared to mexiletine, oral procainamide had a higher efficacy for the treatment of recurrent and refractory VAs, and showed a good profile of tolerability.

Prognostic value of ventricular arrhythmia in early post-infarction left ventricular dysfunction: the French nationwide WICD-MI study.

Prophylactic implantable cardioverter-defibrillators (ICDs) are not recommended until left ventricular ejection fraction (LVEF) has been reassessed 40 to 90 days after an acute myocardial infarction. In the current therapeutic era, the prognosis of sustained ventricular arrhythmias (VAs) occurring during this early post-infarction phase (i.e. within 3 months of hospital discharge) has not yet been specifically evaluated in post-myocardial infarction patients with impaired LVEF. Such was the aim of this retrospective study. Data analysis was based on a nationwide registry of 1032 consecutive patients with LVEF ≤ 35% after acute myocardial infarction who were implanted with an ICD after being prescribed a wearable cardioverter-defibrillator (WCD) for a period of 3 months upon discharge from hospital after the index infarction. ICDs were implanted either because a sustained VA occurred while on WCD (VA+/WCD, n = 72) or because LVEF remained ≤35% at the end of the early post-infarction phase (VA-/WCD, n = 960). The median follow-up was 30.9 months. Sustained VAs occurred within 1 year after ICD implantation in 22.2% and 3.5% of VA+/WCD and VA-/WCD patients, respectively (P < .0001). The adjusted multivariable analysis showed that sustained VAs while on WCD independently predicted recurrence of sustained VAs at 1 year (adjusted hazard ratio [HR] 6.91; 95% confidence interval [CI] 3.73-12.81; P < .0001) and at the end of follow-up (adjusted HR 3.86; 95% CI 2.37-6.30; P < .0001) as well as 1-year mortality (adjusted HR 2.86; 95% CI 1.28-6.39; P = .012). In patients with LVEF ≤ 35%, sustained VA during the early post-infarction phase is predictive of recurrent sustained VAs and 1-year mortality.

Factors associated with stellate ganglion block success in recurrent ventricular arrhythmias.

One treatment option for refractory ventricular arrythmias is stellate ganglion block (SGB). We examined differences in SGB success by patient and arrhythmia characteristics and predictors of successful SGB. This was a multicenter analysis of patients treated for refractory ventricular arrythmias in the Czech Republic and the United States. The primary outcome was absence of ventricular arrythmias at 24h post SGB. SGB effectiveness was examined according to aetiology of cardiomyopathy, arrhythmia type, laterality of SGB, presence of inotropes, and presence of mechanical circulatory support. Binary logistic regression was used to examine variables associated with the primary outcome. In total there were 117 patients with refractory ventricular arrythmias treated with SGB. Overall, the mean age was 63.5±11.0years, majority of patients were male (94.0%), White (87.2%), and had an implantable cardioverter defibrillator in situ (70.1%). There were no differences in efficacy of SGB based on aetiology of cardiomyopathy (P=0.623), arrhythmia type (0.852), laterality of block (P=0.131), and presence of inotropes (P=0.083). Multivariable analysis demonstrated that increased age was associated with decreased odds of SGB success (odds ratio: 0.96, confidence interval: 0.92-0.99, P=0.039) whereas increased left ventricular ejection fraction trended towards increased odds of SGB success (odds ratio: 1.05, confidence interval: 0.995-1.11, P=0.077). In this multicentre experience, SGB was similarly effective despite the aetiology of cardiomyopathy, type of arrhythmia, laterality, and inotropic or mechanical support. SGB was less effective for the suppression of ventricular arrythmias at 24h for the elderly.

Cardiac sarcoidosis in patients with recurrent ventricular arrhythmias refractory to endocardial ablation.

The clinical presentation of cardiac sarcoidosis is diverse. Detection of granuloma in histopathological evaluation proves the diagnosis, but endomyocardial biopsy (EMB) is associated with a high sampling error. However, prompt immunosuppressive therapy may significantly affect patient's prognosis. By analyzing our single center cohort of patients with recurrent ventricular arrhythmias (VA) and nonischemic cardiomyopathy after failure of endocardial ablation, we looked for additional markers supporting the diagnosis of cardiac sarcoidosis. In the last 4years, 135 patients (mean age 49 y, 63% male) were hospitalized for epicardial ventricular arrhythmia (VA) ablation after failure of endocardial ablation. Nineteen patients had either previously received a diagnosis of cardiac sarcoidosis or were newly diagnosed. The mean follow-up time was 4.3years. The ECG criteria, primary manifestation, histological findings in EMB, history of VT ablation, distribution of scars on MRI, electroanatomical mapping (EAM), PET CT findings, presence of atrial tachycardias, valve disease and comorbidities were analyzed. Six of 19 (32%) patients showed right bundle block; 6 of 19 (32%) had AV nodal disease, including 4 patients with AV-block III; and 14 patients (73%) primarily presented with ventricular arrhythmias (including 3 with cardiac arrest). In all 19 patients cardiac EMB revealed elevated CD68 macrophages and CD3 T lymphocytes, and 7 of 19 were positive for granuloma (36,8%). Six of 6 patients (100%) undergoing PET CT showed acute inflammation. By analyzing the scar distribution, the most common locations were basal anteroseptal, basal inferoseptal, mid inferoseptal, mid inferior and the septal RV/RVOT. (septal substrate in 100%). There was a high correlation between the findings on the MRIs and low voltage in the electroanatomical mapping EAM). All patients received an immunosuppressive therapy. No patient died during follow-up, 1 patient had a high urgent heart transplant after withdrawal of steroid therapy. Chronic untreated inflammation may be the underlying pathophysiology for patients with unspecific cardiomyopathy and recurrent VA refractory to endocardial and epicardial ablation. Septal substrate in the EAM/MRI, elevated CD3 lymphocytes in the EBM and inflammation in the PET CT may indicate the possible diagnosis of cardiac sarcoidosis. Initializing immunosuppressive therapy in patients with this dedicated constellation with should be taken into consideration.

Exploring suitability to electrical storm ablation in patients in waiting list for heart transplantation: A single center experience.

Electrical storm (ES) is among the most fearsome events in patients in waiting list for heart transplantation (HT) and catheter ablation (CA) demonstrated to be effective in reduce the arrhythmic burden. However, selection criteria for CA suitability in this specific population have never been addressed before. We retrospectively enrolled 36 patients (mean age 51±8 years; 83% men) waiting HT referred to our department for ES resistant to antiarrhythmic drugs and percutaneous stellate ganglion blockade. Twenty patients were judged suitable for VT ablation according to specific criteria including absence of increased arrhythmic burden secondary to volume overload and hemodynamic decompensation; expected CA outcome favorable due to etiology of the cardiomyopathy, no need for coronary revascularization and technical feasibility of the procedure. The pre-emptive use of mechanical circulatory supports (MCS) were discussed integrating the PAINESD score with additional clinical and hemodynamic parameters. Acute procedural success was accounted in 85% of cases with only two major complications. The CA group reported lower length of in-hospital stay after CA suitability evaluation (56±17vs. 131±64 days, p=.004). Furthermore, at a mean follow-up of 703±145 days, this group showed reduction of ventricular arrhythmia (VA) recurrence leading to implantable cardioverter defibrillator shock (4vs. 8, p=.051) and underwent HT with a lower level of urgency (0vs. 6 patients needed for UNOS1 status upgrade). Respectively, one patient of the CA group and two patients of the conservative group died (p=.839). At the end of follow-up, eight patients underwent heart transplantation (p=.964) while four patients underwent Left Ventricular Assist device (LVAD) implantation (p=.440). This pilot study should be a proof for further studies exploring CA of VAs as a possible bridge therapy to HT.

Percutaneous stellate ganglion blockade as an add-on therapy for the treatment of arrhythmic storm

Abstract Introduction Arrhythmic storm (AS) due to repetitive ventricular arrhythmias (VA) is a life-threatening condition that can be resistant to antiarrhythmic therapy. Sympathetic nervous system plays an important role in triggering and maintaining VA. Reducing sympathetic activity by percutaneous stellate ganglion blockade (SBG) may improve outcomes in treating AS. Purpose To evaluate the effect of SBG on outcomes of AS. Methods In this retrospective study, we analyzed 18 patients treated with SBG for AS from August 2017 to May 2022. All patient experienced VA while on antiarrhythmic drug therapy. SBG was performed under ultrasound guidance to avoid vascular structures. Either 0.75% levobupivacaine or 0.5% ropivacaine were applied to block the stellate ganglion after negative aspiration. The decision to perform unilateral or bilateral SBG was left to the operator. Results The majority of patients were male (17/18, 94.4%), mean age was 61.8 ± 13.4 years, mean BMI 28.1 ± 5.39 kg/m2, mean LVEF was 34.4 ± 12.2%, majority had an ischemic cardiomyopathy (12/18, 66.7%). Half of the patients had monomorphic VA (9/18, 50.0%), the other half had polymorphic VA (9/18, 50.0%). Majority of patients were hemodynamically unstable (13/18, 72.2%) and more than a third had a cardiac arrest (7/18, 38.9%). Half of the patients had unilateral SBG (9/18, 50.0%), and the other half bilateral SBG (9/18, 50.0%). SBG was repeated in two patients (2/18, 11.1%). On the repeat procedure, both had bilateral SBG. There were 4 minor complications (4/18, 22.2%) and no major complications. Two patients had intermittent Horner’s syndrome, one had a small hematoma on the puncture site, and one had small hematoma in the mediastinum. All complications resolved on their own and did not require an intervention. In the 72 hours after SBG, 5 patients had a recurrence of VA (5/18, 27.8%). After the discharge, 6 patients also had a recurrence of VA (6/18, 44.4%). SBG significantly reduced mean number of VA episodes in the next 72 hours (12.3 ± 11.1 vs 4.3 ± 10.6; P=0.007) with a mean difference of 8.0 VA episodes (95% CI, 4.5 - 14.0; P=0.007) (Figure 1). One patient died due to recurrent VA leading to ischemic brain damage (1/18, 5.6%). Four patients died due to non-VA related causes (4/18, 22.2%). Two deaths were due to septic shock, the other two due to cardiogenic shock. Details of baseline characteristics and outcomes are in the Figure 2. Conclusion SBG significantly reduces episodes of VA after failed antiarrhythmic drug therapy in patients presenting with AS.A before-after graph of VA after SBG.Baseline and outcomes table.

Safety and efficacy of a temperature-controlled ablation system for ventricular tachycardia: first results from the TRAC-VT study

Abstract Background Catheter ablation using radiofrequency (RF) energy, is a well-recognized treatment option for patients with ventricular arrhythmias. However, procedural complications may be high, and efficacy is often suboptimal with high recurrence rates. Purpose The TRAC-VT study evaluated safety and efficacy of the DiamondTemp Ablation (DTA) System for the treatment of patients with ventricular arrhythmias by catheter ablation. Methods A temperature-controlled, irrigated RF catheter (with six thermocouples and an internal network of diamond coatings) was utilized to treat subjects with either sustained monomorphic ventricular tachycardia (VT) and structural heart disease or with frequent monomorphic symptomatic ventricular premature beats (VPBs) and normal hearts. Patients were enrolled at five hospital centers in five European countries and were followed for 6 months. Ablation was performed in temperature-control mode with an irrigation flow of 8 mL/min for all power deliveries. The target temperature was set to 55 or 60 °C with a power output limited to 50 Watts. RF energy was applied for a maximum of 45 seconds per target site, depending on impedance drop and electrogram abatement. Results The study enrolled 49 subjects (age 67±12 years, 80% male) in total (38 with sustained monomorphic VT and structural heart disease and 11 with symptomatic VPBs). In all cases, mapping and navigation was used with EnSite systems (Abbott). The average ablation time (defined as time from the insertion of the DTA catheter until removal from body) was 87 ± 44 minutes. During this time, RF energy was applied for an average of 28.2 ± 10.2 seconds with a power of 44.0 ± 7.0 W and a temperature of 50.9 ± 3.9 °C during 35.0 ± 23.2 applications. Acute procedural success was 100% (93%-100%), and it was defined as the elimination of VPBs or non-inducibility for sustained VT (using solely the DTA catheter). The primary safety procedure-related endpoint was an evaluation of cardiovascular-related death, stroke / TIA, cardiac tamponade/perforation, bleeding complication, myocardial infarction, thromboembolism, and pulmonary edema. In total review of the primary safety endpoint, one subject had a confirmation of a stroke / TIA event. Regarding longer term procedural efficacy, the 6-month follow-up was completed in 92% of subjects. For the whole study population chronic success from recurrence of ventricular arrhythmia (faster than 100 beats/min after 6 months) was 73.4% (58.6%-83.6%) for non-sustained ventricular arrhythmias (≥3 beats) and 87.7% (74.7%-94.3%) for sustained ventricular arrhythmias (≥30 sec). Conclusions VT/VPBs ablation using a temperature-controlled irrigated RF catheter was safe and effective with low VT recurrence at 6 months of follow-up.

Renal denervation for the management of refractory ventricular arrhythmias

Abstract Background While catheter ablation (CA) has proven effective in managing ventricular arrhythmias (VA) associated with structural heart disease, a portion of patients continue to experience refractory VA despite medical treatment and multiple CA procedures. In such cases, additional techniques, such as autonomic neuromodulation, have been explored. Renal denervation (RDN), traditionally performed for the treatment of resistant arterial hypertension, inhibits the afferent renal sympathetic pathway, leading to reduced efferent sympathetic overactivation on a systemic level. Due to this mechanism, it has also been studied for the management of arrhythmias, including atrial fibrillation and VA, with favorable results. Objective To assess the effectiveness and safety of RDN for the management of refractory VA storms in high-risk patients. Methods A retrospective analysis of RDN procedures for electrical storms, conducted at a tertiary center between February 2020 and September 2023. We analyzed baseline patient characteristics, procedural details, and acute complications. Recurrence of VA after RDN was assessed at one and six months. Results A total of 7 patients underwent RDN for the treatment of refractory VA. The mean age was 56 ± 10 years (6 male). The primary diagnosis was ischemic cardiomyopathy (n=5), with a mean left ventricular ejection fraction (LVEF) of 20 ± 5%, and no history of resistant arterial hypertension. All patients had an implantable cardioverter-defibrillator (ICD) (two with concomitant resynchronization therapy). Five patients had undergone previous endocardial VA ablation. Of the two patients without prior VA ablation, one had a contraindication because of a large left ventricle thrombus, and the other was submitted to an electrophysiological study, but without inducible ventricular tachycardia. In the four weeks before RDN, patients exhibited a mean of 12 ± 18 sustained VA episodes, meeting the criteria for electrical storm (3 ≥ episodes in 24h). During the procedure, there was a mean of 7 ± 8 radiofrequency applications in the right renal artery and 6 ± 10 in the left renal artery. No acute complications were observed. One month after the procedure, VA episodes were reduced to a mean of 0 ± 1, with only two patients experiencing recurrent VA. After six months, the absence of VA recurrence remained consistent, with only one patient experiencing new episodes. There were no deaths during this period. Conclusion In our pilot study, RDN appeared to be a safe and effective treatment for the management of VA.VA episodes before and after RDN

First experiences with protected VT ablation using surgical Impella 5.5

Abstract Introduction Ablation of ventricular arrhythmias (VA) is still challenging due to the complex substrate of the underlying heart disease. Depending on specific risk factors acute hemodynamic decompensation during or after VT ablation procedures may occur and hemodynamic support may be required. Protected VA ablation with different devices has been evaluated but associated complications like bleeding, vascular closure or weaning from the device have been restrictive. We present data on a dedicated approach to patients with anticipated hemodynamic deterioration using preventive surgical Impella support. Method 5 patients (2 female) underwent protected VT ablation under our standardized protocol. Indication for Impella support was severely impaired left ventricular function and multiple medical therapy refractory ventricular arrhythmias. 4 patients had conventional VT ablation before. Mean age was 66,8 years, mean CHADSVASC 4,4, 1 patient with non-ischemic cardiomyopathy (CMP), 1 with hypertrophic non-obstructive CMP, 3 patients with ischemic CMP. Mean EF was 20%, mean mixed venous saturation was 36 %, mean PAINESD score 27. In all patients a 5.5. Impella was implanted surgically 1 day before planned VT ablation via the right subclavian artery. VT ablation procedure started with substrate mapping, VT induction and activation mapping of the inducible VT to identify the critical VT isthmus. Ablation was directed to dissection of the critical isthmus of inducible VAs and elimination of all late potentials within low voltage areas. The Impella device was explanted after weaning off the hemodynamic support. Results Implantation of Impella 5.5 was successfully performed in all patients in general anesthesia without any complication via surgical approach. Specifically, no access site vascular complications were noted. In 4 patients the VT ablation procedure was performed in analgosedation, 1 patient in GA as this patient was intubated due to recurrent VA requiring defibrillation. Mean procedure time was 125 min, radiation time 1,3 min, inducible VTs 1,3 , median 2 morphologies. In all patients all inducible VTs could be eliminated, in 1 patient polymorphic VA was still inducible at the end of the procedure. Impella was explanted after mean 5,2 days (3-11 days). No complications occurred. All patients were discharged alive on heart failure medication and in 2 patients with amiodaron. At a mean follow up of 3.5 months, all patients are alive without VA recurrence and heart failure decompensation. Conclusion Surgical Impella implantation for protected VT ablation in severe heart failure patients is feasible and allows for effective VT mapping and ablation. Access site safety and protection for heart failure decompensation in addition to the possibility of individually mobilisation and weaning after the procedure make this protocol an attractive option. Prospective evaluation of standardized indication is needed.

Real life experience with point by point pulsed field ablation for recurrent ventricular arrhythmias

Abstract Introduction The safety and effectiveness of electroporation/point by point pulsed field ablation (PP PFA) as emerging technoloy for catheter ablation (CA) of ventricular arrhythmias (VAs) has been described till now only in case reports. Purpose The aim of this observational retrospective study is to present real life data concerning the overall performance of PP PFA for CA of recurrent VA. Methods A total number of 13 consecutive patients (11 VTs and 2 PVCs), in whom recurrent VTs after RF ablation documented, were included. In all patients the substrate location was documented beforehand based on cardiac MRI or CT with myocardial thinning. For substrate mapping a high resolution multipoint mapping catheter was used. A complete success was defined as non inducibility of any arrhythmia at the end of procedure respectively lack of VA recurrence at follow – up. Results Excepting 2 patients, all other had a non ischemic cardiomyopathy as underlying heart disease (mean age 63 ± 8 y/o, mean LVEF 42 % ± 9 %). In every patient at least one conventional RF CA has been performed previously (mean 2 ± 1) and 38 % of patients had a previous epicardial RF VT ablation. The PP PFA VT ablation was performed endocardialy in 11 patients (84 %), respectively epicardialy in 2 patients. The ablation sites had a septal location in 53 % of patients and other localisation in 47 % of patients. The applied energy was 25 A. The overall acute complete success was achieved in 77 % patients. At medium 6 ± 3 months follow up a complete success was present in 46 % cases. Most frequently a VT recurrence after PP PFA ablation was encountered in patients with combined septal and nonseptal substrate distrubution. After PP PFA, the RF CA strategy due to recurrent VAs was endocardial in 2 patients, respectively epicardial 2 in cases and bipolar in 1 case. No PP PFA redos were undergone. Three major complications have been documented (1 tamponade, 1 AV block III° and 1 complete LBBB). Conclusion As bailout strategy in patients with failed conventional CA, PP PFA represents a safe strategy. Specific complications like temporary atrioventricular or intraventricular conduction disturbancies are extremely rare, reversible but not life threathening. The midterm success is satisfactory but still limited in patients with intramural substrate.

Catheter ablation of papillary muscle arrhythmias: procedural characteristics and long term outcome

Abstract Background Ventricular arrhythmias (VA) originating from the papillary muscles can occur both in patients with and without structural heart disease. Although catheter ablation is the treatment of choice, ablation success remains challenging and long-term outcomes for this origin of VA are still unsatisfactory. Methods and Results All patients undergoing catheter ablation for premature ventricular contractions or ventricular tachycardia between june 2009 and november 2022 were analyzed. 66 patients (26 female (39%), mean age 60±15 years) undergoing catheter ablation of VA originating from the papillary muscle were identified. 21/66 (32%) patients had a reduced or mildly reduced left ventricular ejection fraction at time of initial presentation. While mitral valve regurgitation was present in 32/66 (48%) patients, mitral valve prolapse was observed in only 2/66 (3%) patients. 6/66 (9%) patients presented with non-sustained ventricular tachycardia (VT) and 1/66 (2%) patient presented with sustainend VT prior to catheter ablation. 61/66 (92%) patients underwent ablation of PVCs of the left ventricular papillary muscles (22/66 (33%) patients anterolateral; 39 (59%) patients posteromedial). 5/66 patients underwent ablation of premature ventricular complex (PVC) originating from the papillary muscles of the right ventricle. In 13/66 (19.7%) patients only a retrograde approach was used, in 26/66 (39.5%) patients a retrograde and an additional transeptal approach and in only 10/66 (15.2%) patients solely a transeptal approach. Mean PVC QRS duration was 152.5 ± 3.5 msec. Ablation was acutely successful in 44/66 (67%) patients. Mean procedure time was 145.8 ± 63.7 minutes and mean number of radiofrequency applications was 21.3 ± 16.7 (25 to 55 Watts, 37764.2 ± 27824.1 Joules). Overall, procedural complications occurred in 4/66 (6%) patients Follow up data were obtained from Holter ECGs, review of medical records, patient consultation, or via structured follow-up within the prospective TRUST registry. All information was combined to assess recurrence of PVC/VT. Recurrence of VA originating from the papillary muscles occurred in 11/66 (17%) patients. 9/66 patients (14%) underwent re-ablation due to recurrence of VA originating from the papillary muscles after previous ablation procedures. Conclusion Catheter ablation of papillary muscle arrhythmias is associated with a single procedural success rate of 67% with a procedural complication rate of 6%. 14% of patients underwent re-ablation due to recurrence of papillary muscle arrhythmias.

Cardiac magnetic resonance to predict appropriate therapies in secondary prevention

Abstract Introduction Implantable cardioverter-defibrillator (ICD) therapy plays a pivotal role in the management of patient’s survivors of life-threatening ventricular arrhythmias (secondary prevention). Risk of recurrence may be related to presence of myocardial scar and its components (including core mass, border zone (BZ) mass, and BZ channels) assessed with late gadolinium enhancement cardiac magnetic resonance (LGE-CMR). Purpose Our study aims to analyze the role of imaging in predicting the risk of recurrent ventricular arrhythmias and improving the risk stratification for appropriate ICD therapy in patients receiving an ICD for secondary prevention. Methods From 2015 to 2020, a total of 111 patients with LGE-CMR before ICD implantation for secondary prevention. Scar tissue including core, BZ and BZ channels were automatically detected by specialized investigational software in patients with LGE-CMR. Patients were followed until a new event was detected. Results The mean age was 65.4 ± 11.4 years; 87% were men; 55% had ischemic cardiomyopathy. The mean left ventricular ejection fraction was 37.8 % ± 14.31%. Patients were followed for a median of 3.26 years (IQR 1.4-4.9). Within the first year of follow-up 22% of patients had received an appropriate therapy, 39% within 3 years and 53% within 6 years. Chronic kidney disease and New York Heart Association (NYHA) class were associated with the primary endpoint [HR 1.94(1.06-3.55), P-value 0.032)] and [HR 1.86 (1.19-2.91), P-value 0.006)], respectively. Regarding CMR characteristics, BZ percentage was also associated with appropriate ICD therapy in the follow up [HR 1.04(1-1.08), P-value 0.048)]. Other CMR parameter, such as BZ mass, BZ core %, BZ core mass and core mass showed a trend to predict ICD therapies during follow-up. ROC curve analysis with Youden’s index defined an optimal BZ percentage cutoff value for recurrence prediction of 9.5% [HR 0.49 (0.28-0.85)]. Conclusion In patients receiving an ICD for secondary prevention, chronic kidney disease, NYHA class and BZ percentage analyzed by LGE-CMR were predictors of recurrent ventricular arrhythmia. A cutoff of BZ of 9.5% could be used to select patients with high risk of recurrence.