Ventricular Tachycardia Storm Research Articles

Abstract 4135425: Add-on Therapy with Dantrolene, a RyR2 Stabilizer, Terminates Ventricular Tachycardia Storm refractory to Intravenous Amiodarone in Heart Failure.

Background: Aberrant diastolic Ca 2+ leak through the cardiac ryanodine receptor (RyR2) is an important cause of heart failure (HF) and lethal arrhythmia. Dantrolene (DAN) specifically binds to the Leu 601- Cys 620 of N terminal domain in RyR2 and stabilizes the tetrameric structure of RyR2, preventing the Ca 2+ leak through RyR2. Our previous study as a proof-of-concept showed that intravenous injection (i.v.) of DAN was effective in termination and prevention of refractory ventricular tachycardia (VT) storm in HF. Research Question: How much is loading dose of DAN i.v. to terminate VT storm in HF? We hypothesized that the optimal dose was within 3mg/kg from our previous study. Aim: This study aimed to verify that 3mg/kg DAN i.v. was optimal for the termination of amiodarone-resistant VT storm in HF. Methods: This was an open-label, uncontrolled, single-center study. The detail in the study design and methods is shown in Fig.1 . We studied patients with episodes of VT storm regardless of medications, such as amiodarone and beta-blockers, recommended by HF guidelines. DAN(3mg/kg) was intravenously added on the above guideline treatment. The acute anti-arrhythmic efficacy of DAN was assessed as follows: 1) proportion of patients whose VT storm was terminated by 3mg/kg DAN i.v., 2) incidence rate of VT storm within 24 hours before and after DAN i.v.. Results: The consecutive 7 patients with refractory VT storm were enrolled in this study (median age:72 years old, male/female: 4/3, median LVEF29%). Underlying heart disease included 3 ischemic cardiomyopathy, 3 acute myocardial infarction after successful percutaneous coronary intervention and 1 tachycardia-induced cardiomyopathy. 2 of 7 patients underwent mechanical circulatory support before DAN i.v. because of pulseless VT. All patients were classified as NYHA class III/IV. 3 mg/kg of DAN i.v. ceased VT storm within 60 min in 7/7 (100%) (Fig.2, left). The number of sustained VT within 24 h after DAN i.v. were significantly lower than those within 24 h prior to DAN administration (Fig 2, right) . A representative case is shown in Fig.3 The VT storms refractory to amiodarone and landiolol (beta-blocker) as well as sedation showed complete response to 3mg/kg DAN i.v.. Conclusions: DAN, a RyR2 stabilizer, was effective in the termination of VT storm in HF resistant to guideline directed medical treatment. This is the first study to evaluate the optimal dose of DAN i.v. against the refractory VT storm in HF.

Targeting ventricular tachycardia originating from the anterolateral papillary muscle with stereotactic body radioablation therapy

Abstract Background Ventricular Tachycardia (VT) is prevalent in the setting of non-ischaemic cardiomyopathy (NICM), a heterogeneous group of conditions characterized by myocardial dysfunction in the absence of coronary artery disease. Challenges of catheter ablation to treat VT in NICM patients are well known, and recurrence rates can be as high as 58%. Stereotactic body radioablation therapy (SBRT) involves precise delivery of radiation to arrhythmogenic substrates, and represents a novel treatment to reduce recurrent implantable cardioverter defibrillator (ICD) therapies in patients with refractory VT. Though SBRT has shown preliminary effectiveness in reducing VT episodes, its effectiveness in NICM patients has not been widely evaluated. Purpose To evaluate SBRT effectiveness in NICM patients with scars at the basal anterolateral papillary muscle at a tertiary care center between November-December 2022. Methods Eligible patients had their VT substrate mapped using a single-use ECGI vest and a 4D-CT simulation scan. In addition, MRI scans were used to aid anatomical identification of the anterolateral papillary muscle which could not be seen on the non-contrast diagnostic CTs. SBRT was delivered in a single fraction of 25 Gy under image guidance. Effectiveness of the treatment was evaluated as changes in frequencies of total antitachycardia pacing (ATP) and ICD shock episodes from 6 months pre-, and within to 3, 6, and 12 months follow up post SBRT. Results Participants were 3 males with NICM, aged 56, 60, and 73 with previous dual chamber ICD implantation, 2 of whom had a history of VT ablation/ VT storm and paroxysmal atrial fibrillation. All participants had basal lateral scar, and were receiving beta blockers, mexiletine, and amiodarone with refractory VT before SBRT treatment. Prior to SBRT, ICD device interrogation showed a total of 119 (77, 7, and 35 in patients 1-3 respectively) ATPs, and 27 (10, 1, and 16 in patients 1-3 respectively) ICD shocks delivered. At 12 month follow-up, none of the participants experienced any episodes of ATP or ICD shock. Ejection fraction remained consistent pre-post SBRT. Conclusion SBRT showed remarkable success in reducing ATP and ICD shock episodes, facilitating uncomplicated 1 year follow-up in 3 male patients with NICM and VT from the anterolateral papillary muscle.

Use of Esmolol to treat resistant electrical storm in a patient with decompensated heart failure

BackgroundVentricular tachycardia storm is a syndrome defined by the presence of at least three episodes of ventricular tachycardia over a 24-h period, requiring termination by intervention. Standard therapy consists initially of using intravenous betablockers (if left ventricular ejection fraction is preserved) and Amiodarone, in addition to intravenous Lidocaine (in case of ischemic etiology) and light sedation. In the present case, a ventricular tachycardia storm episode is terminated by Esmolol, a particular intravenous betablocker, despite acute decompensated heart failure.Case presentationWe report the case of an 89-year-old patient presenting for a ventricular tachycardia storm and acute heart failure with reduced left ventricle ejection fraction of coronary ischemic origin that persisted despite coronary revascularization, oral betablocker, intravenous Amiodarone and Lidocaine, light sedation, and multiple electrical cardioversion. Emergency catheter ablation was not feasible due to meteorological conditions. We decided to use an intravenous betablocker despite the presence of acute heart failure. We favored use of intravenous Esmolol over other intravenous betablockers due to its short half-life and thus his rapid elimination, a unique characteristic for Esmolol. Intravenous Esmolol has successfully terminated the ventricular tachycardia without causing cardiogenic shock.ConclusionsIntravenous Esmolol can be used safely in patients with acute decompensated heart failure to terminate an electrical storm after failure of other measures. Close monitoring of the patient remains essential.

3D-targeted, electrocardiographic imaging-aided stereotactic radioablation for ventricular tachycardia storm: a case report

Abstract Background Stereotactic arrhythmia radioablation (STAR) is a promising non-invasive therapy for patients with ventricular tachycardia (VT). Accurate identification of the arrhythmogenic volume, or clinical target volume (CTV), on the radiotherapy (RT) 4D planning computed tomography (CT) scan is key for STAR efficacy and safety. This case report illustrates our workflow of electro-structural image integration for CTV delineation. Case summary A 72-year-old man with ischaemic cardiomyopathy and VT storm, despite two (endocardial and epicardial) catheter-based ablations, was consented for STAR. A 3D electro-structural arrhythmia model was generated from co-registered electroanatomical voltage and activation maps, electrocardiographic (ECG) imaging, and the cardiac CT angiography scan (in ADAS 3D), pinpointing the VT isthmus and inferoapical VT exit. At this location, an area with short recovery times was found with ECG imaging. A multidisciplinary team delineated the CTV on the transmural ventricular myocardium, which was fused with the 4D planning CT scan using a digital images and communication in medicine (DICOM) radiotherapy file. The CTV was 63% smaller compared with using the conventional American Heart Association 17-segment approach (11 vs. 24 cm3). A single fraction of 25 Gy was delivered to the internal target volume. After an 8-week blanking period, no VT recurrences or radiation-related side-effects were noted. Eight months later, the patient died from end-stage heart failure. Discussion We report a novel workflow for 3D-targeted and ECG imaging-aided CTV delineation for STAR, resulting in a smaller irradiated volume compared with segmental approaches. Acute and intermediate outcome and safety were favourable. Non-invasive ECG imaging at baseline and during induced VT holds promise for STAR guidance.

Unsupervised machine learning defines subgroups in ischemic heart disease patients presenting with ventricular tachycardia

Abstract Background Ventricular tachycardia (VT) in ischemic heart disease (IHD) is the leading cause of sudden cardiac death (SCD). Despite the well-defined recommendations, tailoring therapies individually is often a challenge owing to the great heterogeneity in this population. We hypothesized that unsupervised machine learning can uncover hidden patterns to identify patient subgroups with similar characteristics. Aims To use unsupervised machine learning methods on a database of patients with ischemic VT, to discover subgroups with similar characteristics and compare the survival of the identified groups. Methods We collected the data of 566 patients with IHD hospitalized for sustained monomorphic VT, excluding those with acute coronary syndrome. The 17 recorded features included medical history and echocardiography. All-cause mortality was registered with one-year follow-up. We performed dimension reduction using T-distributed Stochastic Neighbor Embedding (TSNE) to produce 3 dimensions of the data. Then, we applied spectral clustering to create three groups within the population. Each group was compared to the rest of the population for each variable. Finally, we compared the survival across the three groups using Kaplan-Meyer analysis, univariate Cox-regression, and Log-rank test. Results We identified three groups with distinct characteristics. Group 1 represented the healthiest population; patients had no previous VT hospitalizations, and none of HD instability, LBBB, SCD, diabetes, VT storm or ICD shocks; additionally, they always had a single VT episode at presentation. They showed better left ventricular ejection fraction (LVEF) (38% vs. 33%, p<0.001) and TAPSE (20 mm vs. 18 mm, p=0.01), less severe mitral and tricuspid regurgitation (MR, TR), smaller left ventricular end-systolic diameter, and longer DT. Conversely, patients in Group 2 (n=349) had more previous VT hospitalizations (30% vs. 18%, p=0,003), more often had diabetes (46% vs. 18%, p<0.001), left bundle branch block (23% vs. 13%, p=0.006), and more often presented with HD instability (47% vs. 28%, p<0.001). Group 3 contained all seriously ill patients with VT storm or incessant VT, more commonly presenting with ICD shocks (34% vs. 21%, p=0.004), SCD (24% vs. 15%, p=0.004), hemodynamic instability (50% vs. 37%, p=0.01). This group had the poorest LVEF (30% vs. 35%, <0.001) and TAPSE (17 mm vs. 19 mm p=0.001), more severe MR and TR, and the shortest DT (140 ms vs. 173 ms p<0.001). Finally, we compared survival across the three groups. Significantly better survival was found in Group 1 (HR: 0.52 CI [0.28 - 0.98]) and Group 2 (HR: 0.61 CI [0.42 - 0.88]), while Group 3 had higher mortality (HR: 2.7 CI [1.83 - 3.97]). Conclusions Using spectral clustering we identified three groups in our cohort of ischemic VT patients. This method delineates the group of ischemic VT patients with the highest risk of mortality who might need more aggressive treatment and closer follow-up.

Mid-term outcomes after stereotactic arrhythmia radioablation for refractory ventricular tachycardia

Abstract Introduction stereotactic arrhythmia radioablation (STAR) is used as a rescue treatment for refractory ventricular tachycardia (VT) originating from unreachable myocardial substrate following unsuccessful radiofrequency catheter ablation (RFCA). The mid-term outcomes of STAR, however, remain poorly known. Objective to report the mid-term efficacy and safety outcomes in our series of 21 patients (pts) treated by STAR over 6 years. Methods Inclusion of consecutive pts treated by STAR with a Cyberknife system between 2017 and 2023. 3D-electroanatomical maps (EAM) of the VT substrate during unsuccessful RFCA were used to delineate the planned target volumes (PTV) on a 4D CT scan. Patients were followed up at least every 6 months by echocardiography and ICD interrogation at the outpatient clinic. Results 21 pts [16 (76 %) male, age 66±8 years] with a mean LVEF of 40±15% were included. The underlying substrate was ischemic in 7 (33 %); non-ischemic dilated in 7 (33 %); inflammatory in 4 (19%); hypertrophic in 1 (5%); neoplasic in 1 (5%); and malignant mitral valve prolapse in 1 (5%). A dose of 21±2 Gray was delivered to the PTV (26 ml, IQR 18-43 ml). After a median follow-up of 39 [IQR, 14-48] months, 12 pts (57%) remained in stable condition, 1 (5%) underwent a heart transplantation, 1 (5%) a left ventricular assistance device, 1 (5%) was in an incessant slow VT and 6 (29%) pts died (3 from end stage heart failure). 15 (71%) pts presented VT recurrences [7 (33%) ATPs; 3 (14%) shocks; 4 (19%) VT storm and 1 (5%) with a well-tolerated slow VT (100 bpm) with an LVAD till transplantation, of whom 9 (43%) required redo RFCA. The median value of total ventricular arrhythmic burden (defined as any arrhythmia requiring ICD therapies) decreased significantly from 31 (IQR, 4-100) to 7 (IQR, 1-23) (p<0.05); for nsVT from 57 (IQR, 1.5- 1196) to 41 (IQR, 0.5-584) (p ns); or ICD shocks from 1.5 (IQR, 0-5.5) to 0 (IQR, 0-2) (p<0.05); for ATPs from 21 (IQR, 2.5-94) to 4 (IQR, 0.5-13) (p<0.05). Figure 1 shows a graphic representation of arrhythmic burden before and after STAR. Conclusion in this cohort of highly selected pts with refractory VT, STAR significantly reduced the arrhythmic burden by a factor of 4 over a 3-year follow-up. Death rate remained high (29%), mostly by terminal heart failure. Nevertheless, a high proportion of pts had VT recurrences that were successfully managed by redo RFCA.VT burden before and after STAR

Digital health in the electrophysiological lab: Initial experience, safety and feasibility using remote support for arrhythmia ablation-Results of REMOTE-VA study

Abstract Background In most electrophysiology (EP) labs, electroanatomical mapping (EAM) systems are operated on site by qualified staff or field technical engineers (FTE). Due to lack of skilled personnel, the FTE usually must travel between different hospitals and procedures must be planned in advance. Ablation of ventricular arrhythmias (VA) represents the most complex procedure in the field. The use of remote support (RS) to guide complex EP procedures has the potential to increase flexibility, reduce travel times and maximise healthcare resources. Purpose To evaluate the safety and feasibility of RS as compared to on-site support guided catheter ablation procedures for VA. Methods All patients undergoing ventricular tachycardia (VT) or premature ventricular complex (PVC) ablation using remote support were included. The electronical system of the hospital was searched for 30 days postprocedural emergency department (ED) visits, unplanned ambulatory presentations, and readmissions. RS guided three-dimensional (3D) mapping was achieved by connecting the EAM software with an integrated audio-visual solution for remote support. Internet connection-based headphones and high-resolution cameras ensured the communication between the operator and the FTE, who worked exclusively from home office. The control group consisted of an equal number of patients matched for the type of procedure and undergoing on-site guided procedures. All ablations were performed using high density 3D mapping, as per institutional standard. Results Between October 2022 and October 2023, a total of 25 patients underwent VT (32%) or PVC ablation in our centre using RS and were compared to 25 patients undergoing the same procedures under on-site guidance. In the RS group one patient underwent epicardial VT ablation and another one bipolar ablation for VT Storm. The demographic data were similar between the groups. The median procedure time was 120 (93, 143) minutes in the RS group and 112 (95, 138) minutes in the control group (p=0.95), while the fluoroscopy time was 11.4 (7.0, 14.0) and 7.26 (5.0, 10.9) minutes respectively (p=0.08). The procedural success was achieved in 96% procedures in the RS group and in 100% in the control group. No technical issues or changes to on-site support were reported. One minor intraprocedural complication was noted among the control patients, while 24% of the patients in each group developed minor complications until discharge. Two patients in the RS group and one in the control group had ED visits, while only one patient in the control group had an unplanned ambulatory presentation. One unplanned readmission was reported in the control group (Table 1). Conclusions Even in the most complex procedures including epicardial ablation, the use of RS was feasible and safe in this single centre study. This approach has the potential to increase the feasibility in case of emergency procedures, reduce travel times, and maximise healthcare resources.

A randomized clinical trial of catheter ablation and antiarrhythmic drug therapy for suppression of ventricular tachycardia in ischemic cardiomyopathy: The VANISH2 trial

Recurrent ventricular tachycardia (VT) in patients with prior myocardial infarction is associated with adverse quality of life and clinical outcomes, despite the presence of implanted defibrillators (ICDs). Suppression of recurrent VT can be accomplished with antiarrhythmic drug therapy or catheter ablation. The Ventricular Tachycardia Antiarrhythmics or Ablation In Structural Heart Disease 2 (VANISH2) trial is designed to determine whether ablation is superior to antiarrhythmic drug therapy as first line therapy for patients with ischemic cardiomyopathy and VT.The VANISH2 trial enrolls patients with prior myocardial infarction and VT (with one of: ≥1 ICD shock; ≥3 episodes treated with antitachycardia pacing (ATP) and symptoms; ≥5 episodes treated with ATP regardless of symptoms; ≥3 episodes within 24 hours; or sustained VT treated with electrical cardioversion or pharmacologic conversion). Enrolled patients are classified as either sotalol-eligible, or amiodarone-eligible, and then are randomized to either catheter ablation or to that antiarrhythmic drug therapy, with randomization stratified by drug-eligibility group. Drug therapy, catheter ablation procedures and ICD programming are standardized.All patients will be followed until two years after randomization. The primary endpoint is a composite of mortality at any time, appropriate ICD shock after 14 days, VT storm after 14 days, and treated sustained VT below detection of the ICD after 14 days. The outcomes will be analyzed according to the intention-to-treat principle using survival analysis techniques.The results of the VANISH2 trial are intended to provide data to support clinical decisions on how to suppress VT for patients with prior myocardial infarction.Clinicaltrials.gov registration NCT02830360

Electrical storm after left ventricular assist device (LVAD) implantation.

Ventricular tachycardia storm or electrical storm (ES) is a common complication following left ventricular assist device (LVAD) implantation. The factors contributing to ES and outcomes are less studied. The study aimed to determine the factors associated with ES and the probability of survival in patients undergoing LVAD in three tertiary centers over a span of 15 years. We performed a retrospective cohort study on all patients who underwent LVAD implantation at the Mayo Clinic (Rochester, Phoenix, and Jacksonville) from January 1, 2006to December 31, 2020. ES was defined as ≥3 episodes of sustained ventricular tachycardia over a period of 24 h with no identifiable reversible cause. Detailed chart reviews of the electronic health records within the Mayo Clinic and outside medical records were performed. A total of 883 patients who underwent LVAD implantation were included in our study. ES occurred in 7% (n = 61) of patients with a median of 13 days (interquartile range [IQR]: 5-297 days) following surgery. We found 57% of patients (n = 35) developed ES within 30 days, while 43% (n = 26) patients developed ES at a median of 545 (IQR 152-1032) days after surgery. Following ES, 26% of patients died within 1 year. Patients with ES had a significant association with a history of ventricular arrhythmias and implantable cardioverter defibrillator(ICD) shocks before the procedure. ES was significantly associated with reduced survival compared to patients without ES(hazards ratio [HR]: 1.92, 95% CI: 1.39-2.64, p < .001). Following LVAD implantation, the rate of ES was 7% with majority of ES occurring within 30 days of LVAD. Risk factors for ES included pre-implant history of ventricular arrhythmias and ICD shock. ES was significantly associated with reduced survival compared to patients without ES.

Non-invasive Neuromodulation of Arrhythmias.

Dysfunction of the cardiac autonomic nervous system (CANS) is associated with various cardiac arrhythmias. Subsequently, invasive techniques have successfully targeted the CANS for the treatment of certain arrhythmias, such as sympathetic denervation for ventricular tachycardia storm. Non-invasive strategies capable of modulating the CANS for arrhythmia treatment have begun to gain interest due to their low-risk profile and applicability as an adjuvant therapy. This review provides an evidence-based overview of the currently studied technologies capable of non-invasively modulating CANS for the suppression of atrial fibrillation and ventricular arrhythmias.

SARS-CoV-2 Infection Precipitating VTStorm in Patients With CardiacSarcoidosis.

The authors describe 3 patients presenting with cardiac sarcoidosis (CS) flare and ventricular tachycardia (VT) storm following infection with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), the causative agent of COVID-19. COVID-19-related cardiac manifestations can vary and include arrythmias, myocarditis, and exacerbation of underlying cardiovascular disease. The exact mechanism of myocardial involvement is not clear but may include abnormal host immune response and direct myocardial injury, thereby predisposing to enhanced arrhythmic risk. Arrhythmias account for 20% of COVID-19-related complications with ventricular arrythmias occurring in 5.9% of cases. Further studies are needed to better understand mechanisms underlying the intersection between COVID-19 infection and inflammatory cardiomyopathies.

Surgery for ventricular tachycardia originating from the left ventricular summit.

Ventricular tachycardia (VT) originating from the left ventricular summit region, the most superior region of the left ventricle surrounded by the major coronary arteries and veins, is frequently refractory to pharmacological therapies and endocardial and epicardial catheter ablation. Eleven patients with an age from 31 to 79 (median 56) years old, underwent map-guided surgery for left ventricular summit VT. All patients had undergone 1-5 unsuccessful sessions of catheter ablation for incessant VT, preoperatively. Five patients had suffered VT storm and 1 had a history of cardiopulmonary resuscitation. Four patients had implanted with a defibrillator. Epicardium to endocardium transmural cryothermia was applied at the VT origin determined by intraoperative epicardial mapping with electro-anatomical mapping system. Harmonic scalpel was used to remove the epicardial fat and cryothermia was applied directly to the myocardium, avoiding thermal or mechanical injuries to the coronary vessels. Additional endocardial cryothermia at the VT origin was performed by a cryoprobe introduced into the left ventricular cavity through an aortotomy. There was no surgical mortality or long-term mortality related to VT during a median follow-up period of 60 months (interquartile range: 34-82). Five-year freedom from preoperatively documented left ventricular summit VT and non-documented VT was 91% and 73%, respectively. All the patients with postoperative VT underwent successful catheter ablation. Other patients were free from VT during the follow-up period. Epicardial to endocardial transmural cryothermia at the VT origin guided by intraoperative electro-anatomical mapping with a close collaboration with electrophysiologists was crucial in successful surgery for left ventricular summit VT.

Ischemic or Coronary Evaluations in Patients With Monomorphic VT Electrical Storm Undergoing VT Ablation

BackgroundMonomorphic ventricular tachycardia (VT) electrical storm (ES) in patients with coronary artery disease is dependent on scarred myocardium. The role of routine ischemic or coronary evaluations before ablation in patients presenting with monomorphic VT storm, without acute coronary syndrome (ACS), remains unknown. ObjectivesThis study sought to assess the impact of ischemic or coronary evaluations on procedural outcomes and post-ablation mortality in monomorphic VT storm patients. MethodsAll patients undergoing VT ablation at the Cleveland Clinic from 2014 to 2020 after presenting with monomorphic VT storm were enrolled in a prospectively maintained registry. The associations among ischemic or coronary evaluations and short-term procedural efficacy, acute outcomes, and mortality during follow-up were assessed. ResultsA total of 97 consecutive patients with monomorphic VT storm in the absence of ACS underwent VT ablations. This cohort was characterized by severe LV systolic dysfunction (mean left ventricular ejection fraction 30.3%, 67% with known ischemic cardiomyopathy) with moderately severe heart failure (median NYHA functional class II); 45% of patients underwent ischemic or coronary evaluations via coronary angiography (10%), noninvasive myocardial perfusion (26%), or both (9%). The yield of these evaluations was low: No acute coronary occlusions were identified. There was no association between ischemic evaluation and acute ablation outcomes or mortality during follow-up. Similarly, in a secondary analysis, the yield of ischemic or coronary evaluations in patients with monomorphic VT storm and known coronary disease (regardless of ablation status) was found to be low. ConclusionsIschemic evaluations in patients with monomorphic VT storm without ACS may not improve procedural outcomes or mortality after ablation.

Polymorphic Ventricular Tachycardia Storm After Coronary Artery Bypass Graft Surgery: A Form of 'Angry Purkinje Syndrome'.

Polymorphic ventricular tachycardia (PMVT) is a highly lethal arrhythmia which is commonly caused by acute myocardial ischaemia. PMVT mediated by short-coupled ventricular ectopy patients with ischaemic heart disease but in the absence of acute ischaemia may relate to transient peri-infarct Purkinje fibre irritability and has been termed 'Angry Purkinje Syndrome'. We present a case series of three patients with PMVT storm 3-5 days following coronary artery bypass graft surgery (CABG). In all three cases, recurrent episodes of PMVT were initiated by monomorphic ventricular ectopy with a short coupling interval. Acute coronary ischaemia was excluded in all three patients with a coronary angiogram and graft study. Two out of three of the patients commenced oral quinidine sulphate with subsequent rapid suppression of arrhythmia. Implantable cardiac defibrillators were implanted in all three patients and revealed no recurrence of PMVT following hospital discharge. The Angry Purkinje Syndrome is a rare but important cause of ventricular tachycardia storm after CABG surgery and is mediated by short-coupled ventricular ectopy in the absence of acute myocardial ischaemia. This arrhythmia may be highly responsive to quinidine.

P105: Pre-Emptive Use of Mechanical Circulatory support in sudden cardiac death- A contrasting case series

Life-threatening ventricular tachycardia(VT) and fibrillation(VF) are the most important causes of sudden cardiac death(SCD). Patients who survive are often predisposed to recurrent VT secondary to scar tissue and require definitive ablation therapies. However given the unpredictable nature of arrhythmias, patients can degenerate into VT storm even as outpatient and become hemodynamically unstable which precludes ablation therapies. Using preemptive mechanical circulatory support in such patients as a bridge to ablation can be a game changer, especially in the event of a fresh VT. We present two contrasting cases, where preemptive use of Impella showed better outcomes in neurological status post cardiac arrest. Our patient is a 16-year-old competitive basketball player who suffered an out-of-hospital VT arrest during match practice requiring bystander CPR and multiple shocks. He was stabilized in an outside hospital and brought to us intubated, paralyzed, on multiple pressors and maintained on IV amiodarone and lidocaine. ECHO demonstrated a very large right ventricle (RV) with severe left ventricle(LV) dysfunction, ejection fraction(EF) 10-15% with basal RV diameter 6.8cm. Cardiac MRI(CMRI) showed an area of late gadolinium enhancement (LGE) of the RV-free wall near the apex. Endomyocardial biopsy, Cardiac catheterization, and CT angiogram were unremarkable. With improvement in volume status, he was weaned off all inotropes and antiarrhythmics, received an AICD, and maintained only on sotalol and lisinopril. On outpatient follow-up, repeat CMRI confirmed Arrhythmogenic RV dysplasia. Unfortunately, four months later, the patient had another episode of cardiac arrest secondary to a VT storm with 20 minutes of downtime. He was deemed too unstable for VT ablation and thus emergently underwent a stellate ganglion block. The patient remained encephalopathic post-cardiac arrest with very slow neurologic recovery. He subsequently underwent cardiac transplantation The second case is that of a 63-year-old male with a past medical history of nonischemic cardiomyopathy with LVEF of 10% status post-ICD placement, and VT on amiodarone who presented with episodes of monomorphic VT followed by ICD shocks and syncope. Heart catheterization showed diffuse three-vessel disease. Due to recurrent VT patients, he received an Impella CP as a bridge to VT ablation. Interestingly during ablation, the patient goes into cardiac arrest requiring CPR for 90 minutes. He had successful VT ablation and with no neurological deficit post-procedure. Multiple trials have shown an improved 30-day survival rate without neurological sequelae with early implantation of Impella during ongoing CPR for cardiac arrest. Impella has several favorable properties by unloading the LV which limits the infarct size and maintains cerebral perfusion during the arrest. Preemptive Impella use is often used as a bridge to transplant, however using it as a bridge to ablation is yet to gain prominence.

A new workflow including Coherent algorithm in sinus rhythm for the treatment of Ventricular Tachycardia in patients with scar related heart disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is a well establish therapy in patients with structural heart disease (SHD) and sustain ventricular tachycardia (VT). Scar substrate modification is one of the two endpoint of a VT ablation procedure. Dechanneling is one of the described successful techniques that shown to be effective for substrate modification Aim This is a pilot study aiming to evaluate the feasibility and the acute efficacy of a new mapping approach for VT ablation with the combination of high density (HD) mapping and Coherent mapping algorithm. Methods All enrolled patients underwent radio frequency catheter ablation (RFCA) for drug-refractory VT or VT storm. Before mapping, programmed ventricular stimulation was performed in all patients for the induction of clinical VT or any other ventricular arrhythmias (VA), if VA was inducible, then electrical cardioversion was conducted to restore sinus rhythm. After transseptal puncture, left ventricular (LV) HD mapping was conducted using a 3D mapping system aiming &amp;gt;5000 mapping points during sinus rhythm, intrinsic atrial rhythm, or ventricular pacing with a multielectrode catheter. During HD mapping, all late potentials (LPs) were tagged as double potentials (DP) and all potentials below 0,2 mV were tagged as scar. Then, Coherent mapping was used to visualize electrical propagation through the LV, based on velocity vector identification, highlighting how the electrical signal enters the scar and identifying the "entrance points" (EP). RFCA was delivered in a power-controlled mode on all the individuated EPs using an open, irrigated-tip ablation catheter with contact force sensor. After RFCA, a second remap was conducted to evaluate the LPs abolition. Then, a programmed ventricular stimulation was performed to validate non inducibility of any VAs. Results 10 consecutive patients (age 71,25±10,32 years, 100% male) undergoing RFCA for drug-refractory VT or VT storm (50%). Acute procedural end-point were: abolition of the LPs and non-inducibility of any VA at the end of the procedure. Abolition of LPs was reached in all cases while non inducibility was reached in 9 patients (90%). Mean procedural time was 214±33,81 min, mean mapping time was 89±15,40 min with mean number of acquired points of 5218±359,56. Mean fluoroscopy time and dose were 15±33,81 min and 5218±7149,8 µGm2, respectively. Mean entrance points identified was 2,6±0,84. In 5 patents (50%), after ablation a modification in the refractory period of the left ventricular myocardium was observed. Mean RF time was 1216±565,46 seconds, with mean number of Visitag of 33±29,98. No acute complication were reported. Conclusion High-density mapping in sinus rhythm combined with Coherent algorithm facilitates the understanding of the substrate and provides targets for effective ablation. This approach has been proven safe and with high acute success rates.

Efficacy and safety of catheter ablation of VT using the QDOT Micro catheter: a propensity-matched dual-center comparison with the thermocool SmartTouch catheter

Abstract Funding Acknowledgements Type of funding sources: None. Background Catheter ablation is an increasingly used treatment option for patients with recurrent ventricular tachycardia (VT) or electrical storm (ES). The QDOT Micro (QDOT) Catheter (Biosense Webster) is a novel radiofrequency ablation catheter that was found to allow rapid and effective pulmonary vein isolation among patients with atrial fibrillation. There is no published data on the safety and efficacy of catheter ablation for VT using the QDOT catheter, and few data allow a direct comparison of different technologies in this setting. Purpose to assess outcomes of CA for VT among patients with structural heart disease using the QDOT catheter, and compare them to those observed with the Thermocool Smarttouch (TC-ST, Biosense Webster) catheter. Methods we conducted a dual-center, observational, prospective study enrolling patients with structural heart disease and recurrent VT/ES undergoing catheter ablation with the QDOT catheter. For comparison, we performed a 1:1 propensity score matching to identify patients who underwent VT CA with the TC-ST catheter, using the nearest neighbor method. Propensity score was based on gender, age, etiology of structural heart disease, left ventricular ejection fraction, electrical storm, and number of previous CAs for VT. The primary efficacy outcome was freedom from recurrent VT, as assessed by implantable defibrillator (ICD) interrogation; the primary safety outcome was in-hospital complications. Results Forty propensity-matched patients were included in the analysis (QDOT, n=20; TC-ST, n=20); baseline clinical characteristics are resumed in Table. After a median follow-up of 7 months, survival free from any recurrent VT measured 74 (95% CI, 57-97)% and 69 (95% CI, 51-93)% in the QDOT and TC-ST groups, respectively (log-rank p=0.54, Figure A), while survival free from ICD shocks was 95 (95% CI, 86-100)% versus 84 (95% CI, 69-100)% (log-rank p=0.26, Figure B). There were no major complications in the QDOT group, while three patients (15%) in the TC-ST had a primary safety event (p=0.23; femoral pseudoaneurysm, n=1; cardiac tamponade, n=1; aortic cusp perforation, n=1). Conclusion In a cohort of patients with structural heart disease and recurrent VT or ES, the novel QDOT ablation catheter had similar efficacy and safety compared to the TC-ST catheter. Interestingly, no major procedural complications were observed with the QDOT catheter, suggesting that this device may be safe even in most challenging patients.

PO-05-070 ENDOCARDIAL RADIOFREQUENCY ABLATION OF VT STORM IN CARDIOGENIC SHOCK PATIENTS WITH MECHANICAL CIRCULATORY SUPPORT

Ventricular tachycardia (VT) storm in the setting of cardiogenic shock requiring mechanical support (MCS) carries a high mortality rate. Limited data exist in the literature using VT ablation as a treatment strategy in this cohort of patients. We aim to evaluate the outcome of patients receiving ablation in VT storm complicated by cardiogenic shock requiring MCS, as well as assess predictors for poor outcomes. This is a single-center, retrospective cohort study in patients with refractory VT and cardiogenic shock on MCS, undergoing endocardial ablation from 2015 to 2022. Complete substrate isolation with high output pacing within the scar, followed by stimulation protocols, was used to confirm substrate isolation and the success of ablation. Patients’ demographic and outcome data was obtained from chart review. The PAINESD score, a scoring system to predict early post-procedural mortality of VT ablation, was calculated for each patient. Peak lactate levels recorded during the procedure and preoperative invasive hemodynamic measurements were also taken into consideration. A total of 37 patients with VT storm and concomitant cardiogenic shock on MCS were included. The average age was 61.7 years old, 94.7% were men, with a mean left ventricular ejection fraction of 17.3%, and the average PAINESD score was 24.9. The type of mechanical support utilized is listed in Table 1. Twenty-one were discharged alive, 8 patients (21.6%) with long-term LVAD support, and 13 (35.1%) after weaning support, while 16 patients (43.2%) didn’t survive the index hospitalization (Figure 1). The PAINESD score between those who survived and those who died was not significantly different (25.3 vs. 24.3, p = 0.31). The survivor group had a significantly higher procedure success rate (76.2% vs. 35.3%, p=0.018), higher mean pulmonary artery pulsatility index (PAPI) (2.7 vs. 1.4, p = 0.005), and lower mean intraoperative peak lactic acid level (1.1 vs. 3.5 mmol/L, p = 0.027). Ablation for medication refractory ventricular arrhythmia in cardiogenic shock is efficacious in facilitating mechanical support weaning in a large proportion of the cohort. The absence of right ventricular dysfunction as measured by PAPI, intraoperative lactic acid level, and acute procedure success, as measured by VT inducibility at the end of the procedure, predict the short-term outcome, while the PAINESD score demonstrated weak differentiating power in this moribund, high-risk cohort.

PO-05-145 A CASE OF SUSPECTED CARDIAC SARCOIDOSIS MIMICKING ISCHEMIC CARDIOMYOPATHY

Cardiac sarcoidosis (CS) is challenging due to varied clinical presentation and limited accuracy of diagnostic criteria. We describe a case of suspected CS in a patient with ischemic cardiomyopathy (ICM) presenting in ventricular tachycardia (VT) storm. To describe the presentation of suspected CS in a patient with ICM and VT. N/A A 73 year old male with ICM and ejection fraction of 35% initially presented with myocardial infarct requiring 3-vessel coronary artery bypass surgery. Months later he developed sustained monomorphic VT which was detected on his pacemaker and underwent upgrade to a dual chamber implantable cardioverter defibrillator. He continued to have frequent VT ultimately presenting in VT storm. He was loaded on amiodarone and referred for radiofrequency catheter ablation. During index ablation, the left ventricular (LV) endocardial bipolar voltage was normal, which was inconsistent with the inferobasal and basal septal scar identified on pre procedural cardiac computed topography (CT) (Figure 1). The clinical VT was mapped to the anterior interventricular vein and targeted from the LV summit since proximity of AIV to the left anterior descending artery precluded ablation from the AIV. His arrhythmic presentation and LV dysfunction was disproportionate to degree of coronary disease. In addition, discordance between clinical VT origin site, bipolar endocardial voltage, and scar on cardiac CT prompted suspicion of an alternate underlying diagnosis, such as an arrhythmogenic inflammatory cardiomyopathy. A positron emission tomography/computed tomography (PET/CT) later obtained showed evidence of patchy 18F-fluorodeoxyglucose uptake along the inferolateral LV, suggestive of CS. He was started on immunosuppressants but developed recurrent VT despite anti arrhythmic therapy and required 2 subsequent ablations. He has since remained quiescent from a VT standpoint on amiodarone with plans for alcohol septal ablation or stereotactic body radiation therapy if VT recurs. Symptoms have improved with steroids and immunosuppressants with no inflammation detected on most recent PET/CT High suspicion of CS should remain in patients presenting with significant arrhythmic burden. Normal endocardial voltage during VT ablation can be suggestive of an acute inflammatory process and should prompt consideration of CS, especially in cases with discordant areas of scar and wall thinning on imaging.

PO-05-007 CORONARY VENOUS ETHANOL ABLATION OF SUBEPICARDIAL SUBSTRATE IN PATIENTS WITH VENTRICULAR TACHYCARDIA AND LEFT VENTRICULAR ASSIST DEVICE.

Patients with a left ventricular assist device (LVAD) and ventricular tachycardia (VT) often have subepicardial substrate, which may not be amenable to epicardial ablation due to sternotomy-related adhesions and the LVAD itself. As an alternative approach, coronary venous ethanol ablation (VEA) can be used to ablate VT substrates without needing pericardial access. To assess the feasibility and acute safety of VEA in patients with LVAD and VT. We retrospectively studied patients with LVAD who underwent VT ablation using VEA between 8/2015 – 11/2022 at a tertiary referral medical center. Baseline patient and procedural characteristics were obtained. Of the 10 patients included, 7 presented with VT storm, 5 had prior VT ablation, 3 had multiple prior sternotomies, all were on amiodarone, 8 were on 2 or more antiarrhythmic drugs in the prior year, all had prior defibrillator implants, and 9 had shocks in the prior year. Across the cohort, 4 different vein territories were targeted for VEA, including the middle cardiac vein, posterolateral branch vein, anterolateral branch vein, and septal branch of the anterior interventricular vein. In 4 cases, 2 separate vein territories were targeted. An average of 17 ± 10 cc of ethanol was used per case. Concomitant radiofrequency ablation was used in all 10 patients. Procedure and fluoroscopy times were 290 ± 56 minutes, and 32 ± 15 minutes, respectively. Acute procedural success, defined as no inducible VT, was achieved in 9 cases. There was 1 complication, which was transiently increased threshold on the LV pacing lead and RV failure necessitating prolonged inotropic support. All the patients survived to hospital discharge. In an inherently high-risk LVAD population with VT, VEA can be used as an alternative approach to target subepicardial substrate that would otherwise be inaccessible via standard percutaneous access of the pericardial space. Acute procedural success was high in this limited cohort. Further study with larger numbers of cases and longer follow up is warranted.