Refractory Ventricular Arrhythmias Research Articles

Life-threatening amiodarone-induced thyrotoxicosis – Personalized approach to radical treatment

ObjectiveAmiodarone is an iodine-rich molecule and an effective antiarrhythmic drug. It is a first-line treatment for patients with life-threatening ventricular arrhythmias and for prevention in patients at high risk. The use of amiodarone may cause serious adverse effects such as pharmacotherapy-resistant, life-threatening amiodarone-induced thyrotoxicosis (AIT)leading to rapid deterioration of the patient's condition.According to the European Thyroid Association (ETA) guidelines, emergency thyroidectomy is the first-line treatment option in these cases. ; however, is not always feasible in the clinical setting due to the high anesthetic risk.We aimed to assess the clinical course and results of urgent thyroidectomy and 131-I therapy in patients with severe AIT with worsening of cardiac status. MethodsRetrospective analysis of the clinical course and outcomes of life-threatening AIT refractory to pharmacotherapy in patients hospitalized at a tertiary endocrinology center between 2014 and 2022. ResultsAn electronic database search identified 75 patients hospitalized for severe AIT. At the time of AIT diagnosis, median Thyroid-stimulating hormone (TSH) concentration was 0.001 mIU/L (range 0.001–0.35), fT4 63.2 pmol/L (range 9.0 - >100), and fT3 10.2 pmol/L (range 3.8–49.3). All patients received optimal conservative treatment. Among them, 20 required urgent radical therapy due to worsening arrhythmias and/or AIT-related heart failure. In this group, 6 patients died before any radical treatment was applied, 6 underwent total thyroidectomy, while 8 patients were successfully treated with 131-I (in 6 cases after rhTSH stimulation). The median dose of 131-I used for the therapy was 784MBq (range 627–860). The decision to treat with 131-I despite low but detectable 131-I uptake (median value 6 %) was made in cases of significant contraindications to anesthesia due to refractory ventricular arrhythmias, exacerbation of severe heart failure unresponsive to cardiac treatment, myocardial infarction during AIT course, massive pulmonary embolism. ConclusionThe decision regarding the optimal time and type of radical treatment of AIT refractory to pharmacotherapy is critical for patients management and should not be delayed. Urgent therapy with 131-I may be an effective therapeutic option in patients who are unsuitable for thyroidectomy due to the high risk of anesthesia.

Outcome of Patients With Systolic Heart Failure Who Underwent Sympathectomy for Ventricular Arrhythmia

Cardiac sympathetic denervation (CSD) is a surgical procedure increasingly used for managing ventricular arrhythmia refractory to conventional medical therapy. Long-term outcomes of CSD in patients with systolic heart failure has not been well studied. This observational study aimed to evaluate the medical co-morbidities and outcomes of patients with systolic heart failure who underwent CSD performed as treatment for ventricular arrhythmia refractory to conventional therapy. A retrospective analysis in adult patients with ventricular arrhythmia and systolic heart failure who underwent unilateral or bilateral CSD at a single center was performed. Unadjusted Kaplan-Meier survival curves were constructed to evaluate survival after CSD. Between June 1, 2011 and March 31, 2021, 32 adult patients (age 62 ± 11.6 years, 88% male, left ventricular ejection fraction 22% ± 8.2%) with systolic heart failure underwent unilateral left (n = 4), unilateral right (n = 1), or bilateral CSD (n = 27). Mean survival after CSD was 613 ± 745 days, and the mean time from CSD to death was 291 ± 447 days. The cumulative probability of survival 1 year after CSD was 61.4%. In this single-center observational study, CSD performed for refractory ventricular arrhythmia showed favorable survival in patients with systolic heart failure. In conclusion, this study lays the groundwork for a more in-depth analysis of the potential survival benefits of CSD in this patient group.

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

Coronary venous ethanol ablation of refractory left ventricular summit arrhythmias: comparison with radiofrequency ablation

Abstract Background Radiofrequency (RF) ablation of ventricular premature beats (VPBs) and ventricular tachycardia (VT) arising from the left ventricular (LV) summit is challenging and may fail due to anatomical inaccessibility of the substrate. Coronary Venous Ethanol Ablation (CVEA) has been suggested as a bailout strategy following failed RF ablation of LV Summit Arrhythmias (LVSA). Comparison with RF ablation strategies are lacking. Purpose To compare CVEA with RF ablation for the treatment of LVSA. Methods Between January and November 2023, 20 patients were treated with CVEA for LVSA. Results were compared to 36 patients that underwent RF ablation for LVSA (Panel A). Endo- and/or epicardial RF ablation was performed based on local signal precocity and pace-mapping. Coronary venogram-guided mapping of coronary sinus side-branches was performed using an angioplasty wire connected to our EP-recording system using a crocodile clamp. The target veins were specifically selected based on early presystolic potentials and confirmed by matching VPB pace-maps. For the treatment, angioplasty balloon(s) measuring 2-2.5×6-8 mm were employed to administer ethanol into the target branch of the coronary sinus. Data are reported as mean ± standard deviation, unless otherwise indicated. P-values are two-tailed. Results (Panel B): Patient characteristics were similar for both groups, except for the number of prior failed ablation procedures (75% males; mean age: 63 ± 13 y; 31 with structural heart disease; mean LVEF 39 ± 9%; VPB burden 25 ± 12%; Number of (NS)VT 72 ± 151; 65% redo in case of CVEA, 28% for RF). Mean pace-match was 97 ± 1% (99.8% max.) for CVEA versus 93 ± 8% (97% max.) for RF ablation (P = 0.002). Earliest presystolic signal was -70 ms (-49 ± 12) for CVEA versus -50 ms (-31 ± 12) for RF (P = 0.0002). Acute success, defined as elimination of VPB/VT was 95% versus 83% for CVEA and RF ablation respectively. VPB burden at Holter was 1 ± 3% 6-8 weeks after CVEA versus 8 ± 10% following RF ablation (P = 0.024). In patients with VT, number of (NS)VT decreased by 90% after CVEA (P = 0.014), while this was not significant for RF ablation. After a median follow-up of 8 months (IQR 2-10), 15% of CVEA patients showed residual non-LV summit ventricular arrhythmia as compared to 39% showing recurrence of LV summit VPB or VT following RF ablation. No patients died. One patient developed tamponade following RF ablation and one patient received PCI in the CVEA group. Conclusion Retrograde coronary venous ethanol ablation is an effective ablation strategy for the treatment of LV summit arrhythmias, also compared to conventional RF ablation.

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.

STELLATE GANGLION BLOCK: CLINICAL MONITORING AFTER INJECTION

Abstract 70–year–old man with chronic coronaric syndrome (CABG x 6 in 2006) and HFrEF. ICD implant in primary prevention in 2011. He was admitted for arrhythmic storms refractory to IV lidocaine therapy. Following sedation with midazolam, a left stellate ganglion block was performed using the ultrasound–guided lateral approach, injecting 200 mg of Lidocaine and 200 mg of Mepivacaine. After a few minutes, there was the appearance of anisocoria, different thermotouch in the upper limbs, ptosis, dysphonia, as an effect of local anesthetics on the sympathetic nervous system fibers and on the recurrent laryngeal nerve, near the stellate ganglion. At the same time, the arrhythmias did not recur. Among the rare complications described in the literature (usually transient) arising after stellate ganglion block for the treatment of various chronic pain syndromes or refractory ventricular arrhythmias, we find: hoarseness, stridor, confusion, cough, severe hypertension, subdural/intrathecal block with respiratory arrest, loss of consciousness and paralysis of the four limbs, epileptic seizures, transient locked–in syndrome, headache, visual hallucinations, myoclonus, Horner‘s syndrome, diaphragmatic palsy (phrenic nerve injury), allergic reactions, bleeding and hematoma formation, dural puncture, pneumothorax, local infections. Serious adverse effects described include cases of death or tetraplegia following epidural abscess. For this reason, it is of utmost importance monitoring after the procedure and the availability of the equipment necessary for a possible resuscitation to avoid long–term of sequelae. Conclusion In cases of arrhythmic storm refractory to antiarrhythmic therapy, percutaneous stellate ganglion block is an effective and safe procedure and serious complications are rare.

Radiation therapy for ventricular arrhythmias.

Ventricular arrhythmias (VA) can be life-threatening arrhythmias that result in significant morbidity and mortality. Catheter ablation (CA) is an invasive treatment modality that can be effective in the treatment of VA where medications fail. Recurrence occurs commonly following CA due to an inability to deliver lesions of adequate depth to cauterise the electrical circuits that drive VA or reach areas of scar responsible for VA. Stereotactic body radiotherapy is a non-invasive treatment modality that allows volumetric delivery of energy to treat circuits that cannot be reached by CA. It overcomes the weaknesses of CA and has been successfully utilised in small clinical trials to treat refractory VA. This article summarises the current evidence for this novel treatment modality and the steps that will be required to bring it to the forefront of VA treatment.

A Multicenter Study of Stellate Ganglion Block as a Temporizing Treatment for Refractory Ventricular Arrhythmias

BackgroundVentricular tachycardia (VT) and ventricular fibrillation (VF) are life-threatening conditions and can be refractory to conventional drug and device interventions. Stellate ganglion blockade (SGB) has been described as an adjunct, temporizing intervention in patients with refractory ventricular arrhythmia. We examined the association of SGB with VT/VF in a multicenter registry. ObjectivesThis study examined the efficacy of SGB for treatment/temporization of refractory VT/VF. MethodsThe authors present the first analysis from a multicenter registry of patients treated for refractory ventricular arrhythmia at a clinical site in the Czech Republic and the United States. Data were collected between 2016 and 2022. SGB was performed at the bedside by anesthesiologists and/or cardiologists. Outcomes of interest were VT/VF burden and defibrillations at 24 hours before and after SGB. ResultsIn total, there were 117 patients with refractory ventricular arrhythmias treated with SGB at Duke (n = 49) and the Institute for Clinical and Experimental Medicine (n = 68). The majority of patients were male (94.0%), were White (87.2%), and had an implantable cardioverter-defibrillator (70.1%). The most common etiology of heart disease was ischemic cardiomyopathy (52.1%), and monomorphic VT was the most common morphology (70.1%). Within 24 hours before SGB (0-24 hours), the median episodes of VT/VF were 7.5 (Q1-Q3: 3.0-27.0), and 24 hours after SGB, the median decreased to 1.0 (Q1-Q3: 0.0-4.5; P < 0.001). At 24 hours before SGB, the median defibrillation events were 2.0 (Q1-Q3: 0.0-8.0), and 24 hours after SGB, the median decreased to 0.0 (Q1-Q3: 0.0-1.0; P < 0.001). ConclusionsIn the largest cohort of patients with treatment-refractory ventricular arrhythmia, we demonstrate that SGB use was associated with a reduction in the ventricular arrhythmia burden and need for defibrillation therapy.

One-year mortality and cause of death after stereotactic radiation therapy for refractory ventricular arrhythmias

One-year mortality and cause of death after stereotactic radiation therapy for refractory ventricular arrhythmias

Cardiac stereotactic radiation therapy for refractory ventricular arrhythmias in patients with left ventricular assist devices.

Left ventricular assist device (LVAD) implantation is an established treatment for patients with advanced heart failurerefractory to medical therapy. However, the incidence of ventricular arrhythmias (VAs) is high in this population, both in the acute and delayed phases after implantation. About one-third of patients implanted with anLVAD will experience sustained VAs, predisposing these patients to worse outcomes and complicating patient management. The combination of pre-existing myocardial substrate and complex electrical remodeling after LVAD implantation account for the high incidence of VAs observed in this population. LVAD patients presenting VAs refractory to antiarrhythmic therapy and catheter ablation procedures are not rare. In such patients, treatment options are extremely limited. Stereotactic body radiation therapy (SBRT) is a technique that delivers precise and high doses of radiation to highly defined targets, reducing exposure to adjacent normal tissue. Cardiac SBRT has recently emerged as a promising alternative with a growing number of case series reporting the effectiveness of the technique in reducing the VA burden in patients with arrhythmias refractory to conventional therapies. The safety profile of cardiac SBRT also appears favorable, even though the current clinical experience remains limited. The use of cardiac SBRT for the treatment of refractory VAs in patients implanted with anLVAD are even more scarce. This review summarizes the clinical experience of cardiac SBRT in LVAD patients and describes technical considerations related to the implementation of the SBRT procedure in the presence of anLVAD.

Bipolar ablation involving coronary venous system for refractory left ventricular summit arrhythmias

Catheter ablation of premature ventricular complexes (PVCs) and ventricular tachycardia (VT) from the left ventricular summit (LVS) may require advanced ablation techniques. Bipolar ablation from the coronary veins and adjacent endocardial structures can be effective for refractory LVS arrhythmias. The aim of this study was to investigate the outcomes of bipolar ablation performed between the coronary venous system and adjacent endocardial left ventricular outflow tract (LVOT) or right ventricular outflow tract (RVOT). This multicenter study included consecutive patients with LVS PVC/VT who underwent bipolar ablation between the anterior interventricular vein (AIV) or great cardiac vein (GCV) and the endocardial LVOT/RVOT after failed unipolar ablation. Ablation was started with powers of 10-20 W and uptitrated to achieve an impedance drop of at least 10%. Angiography was performed in all cases to confirm a safe distance (>5 mm) of the catheter from the major coronary arteries. Between 2013 and 2023, bipolar radiofrequency ablation between the AIV/GCV and the adjacent LVOT/RVOT was attempted in 20 patients (4 female; age 57 ± 16 years). Unipolar ablation from sites of early activation (AIV/GCV, LVOT, aortic cusps, RVOT) failed to effectively suppress the PVC/VT in all subjects. Bipolar ablation was delivered with a maximum power of 30 ± 8 W and total duration of 238 ± 217 s and led to acute PVC/VT elimination in all patients. No procedural-related complications occurred. Over a follow-up period of 30 ± 24 months, the freedom from arrhythmia recurrence was 85% (1 recurrence in the VT group and 2 in the PVC group). PVC burden was reduced from 22% ± 10% to 4% ± 8% (P <.001). In cases of LVS PVC/VT refractory to unipolar ablation, bipolar ablation between the coronary venous system and adjacent endocardial LVOT/RVOT is safe and effective if careful titration of power and intraprocedural angiography are performed to ensure a safe distance from the coronary arteries.

Intraoperative cardiac arrest caused by unexpected vasospastic angina requiring prolonged resuscitation using extracorporeal membrane oxygenation: a case report

BackgroundVasospastic angina (VSA) occurring during surgery is rare but can lead to sudden intraoperative cardiac arrest.Case presentationA 77-year-old man with hypertension, and no history of coronary artery disease, displayed an abrupt ST-segment elevation on the electrocardiogram (ECG) during laparoscopic inguinal hernia surgery under general anesthesia. Subsequently, ventricular fibrillation (VF) occurred, with a finding suggesting ischemic myocardial contracture by transesophageal echocardiography. VF was refractory to cardiopulmonary resuscitation (CPR), and veno-arterial extracorporeal membrane oxygenation (VA ECMO) was introduced. Spontaneous circulation resumed 77 min post-cardiac arrest. VSA was confirmed through the patient’s clinical course and coronary angiography. Subsequently, VA ECMO was terminated, and the patient was discharged uneventfully.ConclusionsExtracorporeal CPR may be a valuable alternative to extended resuscitation for refractory ventricular arrhythmias by VSA.

Bilateral Cardiac Sympathetic Denervation for Refractory Multifocal Premature Ventricular Contractions in Patients With Nonischemic Cardiomyopathy

BackgroundBilateral cardiac sympathetic denervation (BCSD) for refractory life-threatening ventricular arrhythmias is a neuromodulatory intervention targeting sympathetically driven focal or re-entrant ventricular arrhythmias. ObjectivesThis study sought to provide a more complete and successful option for intervention in patients in whom premature ventricular contraction (PVC) ablation is not feasible or has been unsuccessful. MethodsA total of 43 patients with >5% PVC burden and concomitant nonischemic cardiomyopathy (NICM) who previously failed medical and ablation therapies were referred for BCSD. All patients underwent bilateral video-assisted thoracoscopic surgical approach with T1-T4 sympathectomy. Primary effectiveness endpoints were postprocedural PVC burden resolution, improvement in left ventricular ejection fraction (LVEF), and cessation of antiarrhythmic drugs (AADs). Safety endpoints included peri- and postprocedural complications. Outcomes were assessed over a 1-year follow-up period. ResultsAmong the 43 patients who underwent BCSD, the mean age was 52.3 ± 14.7 years, 69.8% of whom were male patients. Presenting mean LVEF was 38.7% ± 7.8%, and PVC burden was 23.7% ± 9.9%. There were significant reductions in PVC burden postprocedurally (1.3% ± 1.1% post-BCSD, compared with 23.7% ± 9.9% pre-BCSD, P < 0.001) and improvements in LVEF (46.3% ± 9.5% post-BCSD, compared with 38.7% ± 7.8% pre-BCSD, P < 0.001). The rate of ICD therapies decreased from 81.4% (n = 35) to 11.6% (n = 5) (P < 0.001), leading to a significant reduction in use of AADs (100.0% to 11.6%, P < 0.001) and improvement in mean NYHA functional class (2.5 ± 0.5 to 1.4 ± 0.2, P < 0.001). Major intraoperative complications were seen in 4.7% of patients (hemothorax and chylothorax). Of the patients, 81.4% (n = 35) experienced no mortality or major complications over a 1-year follow-up period, with the remaining still within their first year postprocedure. ConclusionsBCSD is effective for the management of refractory PVCs and ventricular tachycardia who have failed previous ablation therapy.

Abstract 13790: Efficacy of Stellate Ganglion Block for Refractory Ventricular Arrhythmias: An Updated Systematic Review

Background: Stellate ganglion block (SGB) has emerged as an alternative approach to refractory ventricular arrhythmias (VAs). However, data on the outcome of SGB for refractory VAs are limited. Objective: This study aimed to assess the in-hospital efficacy of SGB in refractory VAs. Method: A systematic search was performed in MEDLINE and EMBASE according to the PRISMA guidelines from July 2017 to October 2022. Studies reporting the characteristics of in-hospital VAs before and after the SGB were included. Studies that had missing outcomes were excluded. Results: Of 515 publications reviewed, 162 patients (60.6 ± 13.6 years of age, 81.5% male) were included across 27 studies. Amongst, 103 patients (63.6%) had ischemic cardiomyopathy, and the mean ejection fraction was 29.8 ± 12.7%. Prior to the SGB procedure, 100 patients (61.7%) required two or more anti-arrhythmic medications control. Following SGB, there was a significant 92% reduction of VAs episodes from 13.9 ± 18.5 to 0.9 ± 2.1 (p&lt;0.01) during the hospitalization (31±35 days). Of the reported patients, 46.5% remained free of VAs, and 53.5% had recurrences before discharge. Among 61 patients who required additional neuromodulation after SGB in the same hospitalization, 32 patients (52.5%) received repeated SGB, 15 patients (24.6%) underwent surgical sympathectomy, and 14 patients (23%) underwent catheter ablation. Of the reported patients, 75.4% of patients survived throughout the hospital course. Conclusion: SGB significantly reduced VAs episodes in patients with refractory VAs during hospitalization. More than three-quarters of the patients survived following the SGB for refractory VAs. This highlights the potential effective role of SGB in managing refractory VAs. Figure Change in Ventricular Arrhythmias Burden after Stellate Ganglion Block

Abstract 16745: Continuous Stellate Ganglion Block for Ventricular Arrhythmias: Case Series, Systematic Review and Comparison With Epidural Anesthesia

Background: Percutaneous single bolus injection left stellate ganglion block (PLSGB) and thoracic epidural anesthesia (TEA) have been proposed for the acute management of refractory ventricular arrhythmias (VAs). Data on continuous PLSGB (C-PLSGB) are scant. Objectives: to report our single center experience with C-PLSGB and perform a systematic review on C-PLSGB and TEA to preliminary compare these 2 techniques. Methods: consecutive patients receiving C-PLSGB were enrolled. The systematic literature review was performed following the latest PRISMA criteria. Results: our single-center case series (8 pts, 88% male, 60 ±16 years, all with structural heart disease) supports that C-PLSGB is feasible and safe, even on fully anticoagulated patients and leads to a complete VAs suppression in half and to an overall clinical benefit in all patients. Overall, considering previously published data, 34 patients received C-PLSGB, and 18 TEA for refractory VAs. Most (61%) in the TEA group were on general anesthesia, as opposed to 24% in the C-PLSGB group (p=0.01); 52% of patients were on full anticoagulation at C-PLSGB, none at TEA (p&lt;0.01). C-PLSGB and TEA efficacy was not significantly different (31/34 versus 13/18 had a complete or at least partial response, p=0.1). No major complications occurred, yet the discontinuation rate was significantly higher in the TEA compared to C-PLSGB (22% versus 3%, p=0.037). Conclusions: C-PLSGB seems feasible, safe and effective for the acute management of refractory VAs. C-PLSGB efficacy seems to be not significantly different to that of TEA and may be accomplished with less concerns of anticoagulation, and lower discontinuation rate.

Abstract 16815: Outcomes of Cardiac Sympathetic Denervation via Cautery Ablation for Ventricular Arrhythmia: A Single Center Study

Introduction: Cardiac sympathectomy denervation (CSD) has been demonstrated to reduce ventricular arrhythmia (VA) burden and to improve arrhythmia-free survival. Early evidence for the clinical antiarrhythmic benefits for CSD was established in patients with long-QT syndrome and catecholaminergic polymorphic VT (CPVT). Its benefit has subsequently been shown to extend to other undifferentiated cardiomyopathies. Hypothesis: Literature on CSD for VA has been limited due to a small number of patients. Our retrospective study is to review patients who underwent CSD for VA at our center via cautery ablation. Methods: We identified 9 patients who underwent CSD from 4/2018 to 2/2022. Electronic medical record was reviewed for clinical history and outcomes. Results: Mean age was 52±17 and 5 patients (55.6%) were male. Seven patients (77.8%) had nonischemic cardiomyopathy (NICM) and 2 patients (22.2%) had CPVT. Mean LVEF was 43±19% and 5 patients (55.6%) had heart failure with NYHA class 3±0.7. Five patients (55.6%) underwent CSD in outpatient setting and 4 patients (44.4%) had polymorphic VT. Six patients (66.7%) had prior catheter-based VT ablation, 1 patient (11.1%) had prior ganglion block, and 4 patients (44.4%) had history of VT storm. All patients were on antiarrhythmics ranging from a beta blocker monotherapy to a combination of class Ic, class III, and a beta blocker. Seven patients (77.8%) had a defibrillator prior to CSD. All patients underwent CSD (7 with bilateral and 2 with left only) without any procedural complication. Five patients (55.6%) had recurrence of VA in 423±567 days with follow-up duration of 729±478 days. Three patients (33.3%) underwent heart transplant or LVAD and three patients (33.3%) died in 426±396 days since CSD. Overall, 3 patients (33.3%) including 2 CPVT patients and one NICM patient with normal EF were free of death, sustained VT, or advanced heart failure therapies. Conclusions: CSD via cautery ablation is safe and effective for patients with refractory VA to antiarrhythmics and/or VT ablation. Success rate appeared to be higher in patients with CPVT and normal EF. Lower rate of survival and freedom from VT or transplant/LVAD compared to published literature may reflect our sick population.

Abstract 15291: Early Outcomes With Left Cardiac Sympathetic Denervation for Medically Refractory Idiopathic Ventricular Fibrillation

Introduction: Treatment options for patients with recurrent ventricular arrhythmias (VAs) refractory to pharmacotherapy and/or ablation are minimal. Although left cardiac sympathetic denervation (LCSD) is well established in long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT), LCSD’s role in idiopathic ventricular fibrillation (IVF) is less clear. Here, we report our single-center experience regarding the early outcomes of LCSD in patients with IVF. Hypothesis: To determine the efficacy of LCSD on reducing VAs in IVF patients refractory to conventional therapy. Methods: A retrospective analysis of the electronic health record of patients with IVF between January 2000 to April 2023 was performed. Cardiac event rates [defined as arrhythmic syncope/seizure, appropriate implantable cardioverter defibrillator (ICD) therapy, sudden cardiac arrest (SCA), or sudden cardiac death (SCD)] before and after LCSD for each patient were calculated and a Wilcoxon signed rank test was performed. Results: In total, 94 patients (41% female) were classified as IVF. Overall, 15/94 patients (16%) had LCSD due to refractory VAs (60% male; mean age at LCSD 36 ± 20 years) despite beta-blocker treatment (100%) or combined drug therapy (67%). In total, 14 patients (15%) had an electrophysiology study performed before LCSD of which 10 (67%) had VAs ablation. All patients had a structurally normal heart and genetic testing performed in 14/15 patients (93%) confirmed absence of genetic cardiomyopathies and channelopathies. SCA was the sentinel event in 10 of 15 patients (67%); 14 patients (93%) had an ICD in place. The average follow-up time after LCSD was 3 ± 4 years. The VA event rate before LCSD was 4 ± 3 events per year and was reduced to 1 ± 3 per year (p&lt;0.04) after LCSD. Patients had a median of 3.2 less events per year after LCSD (p=0.02) with 7 patients (47%) having no post-LCSD recurrences thus far while 3 (20%) patients were deemed LCSD non-responders with no reduction of event rate. Conclusions: LCSD represents a substrate-independent, anti-fibrillatory treatment option for patients with life-threatening, genetic arrhythmias. While not curative, the early outcomes of LCSD for patients with medically refractory IVF are promising.

Pediatric extracorporeal cardiopulmonary resuscitation for yew cardiotoxicity.

English yew is an evergreen conifer frequently planted in household gardens and, when ingested in large doses, results in severe cardiotoxicity characterized by difficult to control ventricular arrhythmias with high rates of mortality. A previously healthy teenage female presented as an out-of-hospital cardiac arrest with refractory ventricular arrhythmias and severe biventricular dysfunction. Due to rapid deterioration in her clinical status, she was cannulated onto venoarterial extracorporeal membrane oxygenation (ECMO) which resulted in rapid normalization of her rhythm and ventricular function. Our case highlights the importance of keeping a broad differential diagnosis when considering etiologies of ventricular arrhythmias in the pediatric population. The final diagnosis was not made until after discharge and implantable cardiac defibrillator (ICD) placement. The delayed diagnosis of this intentional English yew ingestion ultimately resulted subsequent ICD removal. Early ECMO activation in cases of English yew toxicity can be essential for patient survival.

Management of refractory intramural left ventricular summit ventricular arrhythmia: Acute success using bipolar radiofrequency catheter ablation with recurrence.

Bipolar radiofrequency catheter ablation (RFCA) is a novel strategy for refractory or recurrent ventricular arrhythmias (VAs) resistant to conventional ablation methods. Lesions created during bipolar RFCA are larger than those created during sequential unipolar ablation. We present a case of refractory LV summit VAs, which identified the origin using a 2.7-F over-the-wire microelectrodes catheter, and it was successfully treated with bipolar RFCA in the acute phase.

Case report: A case of complete resolution of obstructive and central sleep apnea with Cheyne Stokes breathing in a patient with heart failure 60 days post-left ventricular assist device implantation

Sleep-disordered breathing (obstructive and central sleep apnea) are common in patients with heart failure with reduced ejection fraction. Herein, we report a 69-year-old patient with a history of severe heart failure and refractory ventricular arrhythmia who was diagnosed with a moderate degree of obstructive and central sleep apnea with Cheyne Stokes breathing. He underwent a successful implantation of left ventricular assist device. Our patient had a complete resolution of both obstructive and central sleep apnea 60 days post-LVAD implantation as confirmed by home sleep apnea test.