Functional ElectroAnatomiC Isochronal Late Activation Mapping For Empiric VT Ablation Trial

Overview

About this study

This is a multicenter, prospective, parallel, randomized controlled trial to test for non-inferiority with an ILAM-guided VT ablation compared to conventional voltage- based ablation. The study has two treatment arms: conventional voltage mapping and ablation (control arm). In the investigational arm, the ablation strategy is guided by ILAM to target deceleration zones, blinded to voltage mapping. In the control arm, ablation will be performed to extensively ablate all low voltage regions (\<1.5mV) during sinus rhythm, right ventricular (RV) pacing, or left ventricular (LV) pacing, with discretionary use of pacemapping and activation mapping. In both arms, mapping with be performed with a multielectrode catheter (HD Grid) and ablation will be performed using an irrigated tip catheter (FlexAbility SE or Tactiflex catheters).

In the control armonly voltage mapping displays will be utilized (blinded to functional ILAM and fractionation). High density mapping with automated last deflection annotation (Ensite X) will be performed in all patients randomized to ILAM approach during either sinus rhythm or RV pacing.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. There is no guarantee that every individual who qualifies and wants to participate in a trial will be enrolled. Contact the study team to discuss study eligibility and potential participation.

Inclusion Criteria

To participate in this clinical investigation, the subjects must meet all of the following inclusion criteria:

1. Patient is ≥18 years of age.
2. Able and willing to comply with all study requirements.
3. At least one documented episode of sustained MMVT (\>30 sec) by either EGM or ECG (including Holter, or loop recorder) in the 6 months prior to enrollment.
4. Informed of the nature of the study, agreed to its provisions, and has provided written informed consent as approved by the Institutional Review Board/Ethics Committee (IRB/EC) of the respective clinical study site.
5. Refractory (i.e., not effective, not tolerated, or not desired) to at least one anti-arrhythmic medication (including, but not limited to beta blocker, mexiletine, amiodarone or sotalol) for treatment of MMVT.
6. Structural heart disease (ischemic or non-ischemic) with one of the following (a, b or c):

1. Evidence of myocardial scar by echocardiography (segmental wall motion or wall thinning), CT (wall thinning) and/or MRI (presence of delayed enhancement /late gadolinium enhancement) . CT or MRI with scar is mandatory for inclusion of NICM., or
2. Left ventricular ejection fraction (EF) \<50% \[documented within the last 6 months via transthoracic echocardiogram (TTE), MRI\] with presence of scar, or
3. Arrhythmogenic RV cardiomyopathy/dysplasia (per 2010 ARVC/D Task Force Criteria)

Exclusion Criteria

Subjects who meet any of the following exclusion criteria must be excluded from the clinical investigation:

1. Active infection (positive blood culture).
2. Patient is pregnant or nursing.
3. Cardiac surgery via sternotomy (CABG or valve repair/replacement) within 30 days prior to enrollment.
4. Contraindication to systemic anticoagulation (i.e., heparin, warfarin, or a direct thrombin inhibitor).
5. Currently receiving support via extracorporeal membrane oxygenation (ECMO) or ventricular assist device (VAD).
6. Left Ventriclar ejection fraction \< 15%.
7. Stroke within 30 days or presence of LV thrombus within 1 month prior to enrollment.
8. Idiopathic VT or preprocedural imaging without scar (MRI or CT).
9. Limited life expectancy of 1 year or less.
10. Presence of mitral and aortic valves both mechanical.
11. Ventricular tachycardia secondary to electrolyte imbalance or any other reversible or non-cardiac cause.
12. Severe aortic stenosis or flail mitral valve with severed mitral regurgitation.
13. Thrombocytopenia (defined as platelet count \<50,000/μl ) or coagulopathy.
14. Ventricular arrhythmias secondary to underlying channelopathies (LQTS, Brugada Syndrome).
15. Enrolled in an investigational study evaluating another device or drug that would confound the results of this study.
16. Other anatomic or co-morbid conditions that, in the investigator's opinion, could limit the patient's ability to participate in the study or to comply with follow up requirement of 1 year, or impact the scientific integrity of the study results.

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 9/09/2025. Questions regarding updates should be directed to the study team contact.

Participating Mayo Clinic locations

Study statuses change often. Please contact the study team for the most up-to-date information regarding possible participation.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Ammar Killu

Open for enrollment

Contact information:

CVRU Heart Rhythm Services Research Team

(507) 255-0774

More information

Publications

  • This study aimed to evaluate the feasibility and accuracy of using a novel grid mapping catheter during scar-related ventricular tachycardia (VT) ablation. Read More on PubMed
  • Sinus rhythm surrogates for critical isthmus sites are highly desirable because the vast majority of VT is hemodynamically unstable. While many ablation strategies to decrease the arrhythmogenicity of scar have been shown to be effective, the predominant method for electroanatomic mapping relies on a voltage-based depiction of scar and abnormal electrograms. A functional prioritization of slow conduction, distinct from late activation, is feasible in clinical practice with the creation of isochronal late activation maps. Regions of slow conduction are easily visualized with isochronal displays of baseline intrinsic rhythm activation and deceleration zones, where isochrones crowd, have been observed to have strong correlation with successful ablation sites. Automated annotation of the offset of local electrograms was developed to create the propagation maps to incorporate electrogram width and completion of local activation. Simple conduction velocity estimates where three isochrones are seen within a 1 cm radium confirm that deceleration zones harbor conduction velocity of <0.6 m/s. We present a practical methodology of analyzing electroanatomic substrate in a voltage-independent manner with correlation to reentrant VT. Non-linear 3D transmyocardial conduction limits the validity of conduction velocity estimates that assume planar and tangential conduction and we show an example of a patient with 3D isthmus boundaries with an activation gap on the epicardial surface during tachycardia. Read More on PubMed
  • Studies analyzing optimal voltage thresholds for scar detection with electroanatomic mapping frequently lack a gold standard for comparison. Read More on PubMed
  • Recurrent ventricular tachycardia among survivors of myocardial infarction with an implantable cardioverter-defibrillator (ICD) is frequent despite antiarrhythmic drug therapy. The most effective approach to management of this problem is uncertain. Read More on PubMed
  • The impact of catheter ablation of ventricular tachycardia (VT) on all-cause mortality remains unknown. Read More on PubMed
  • It is not known whether the most delayed late potentials are functionally most specific for scar-related ventricular tachycardia (VT) circuits. Read More on PubMed
  • We conducted this pilot randomized clinical trial to determine the feasibility of a large clinical trial aimed at testing whether early use of catheter ablation of ventricular tachycardia (VT) is superior to antiarrhythmic medications at reducing mortality. Read More on PubMed
  • To evaluate the efficacy of radiofrequency ventricular tachycardia (VT) ablation targeting complete late potential (LP) activity. Read More on PubMed
  • Catheter ablation of ventricular tachycardia (VT) is effective and particularly useful in patients with frequent defibrillator interventions. Various substrate modification techniques have been described for unmappable or hemodynamically intolerable VT. Noninducibility is the most frequently used end point but is associated with significant limitations, so the optimal end point remains unclear. We hypothesized that elimination of local abnormal ventricular activities (LAVAs) during sinus rhythm or ventricular pacing would be a useful and effective end point for substrate-based VT ablation. As an adjunct to this strategy, we used a new high-density mapping catheter and frequently used epicardial mapping. Read More on PubMed
  • Contact mapping of the ventricle with NAVX has not been validated. Read More on PubMed
  • Ultra High-Density Multipolar Mapping With Double Ventricular Access.  Read More on PubMed
  • The purpose of this study was to compare the characteristics and prevalence of late potentials (LP) in patients with nonischemic cardiomyopathy (NICM) and ischemic cardiomyopathy (ICM) etiologies and evaluate their value as targets for catheter ablation. Read More on PubMed
  • In 1994, an International Task Force proposed criteria for the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) that facilitated recognition and interpretation of the frequently nonspecific clinical features of ARVC/D. This enabled confirmatory clinical diagnosis in index cases through exclusion of phenocopies and provided a standard on which clinical research and genetic studies could be based. Structural, histological, electrocardiographic, arrhythmic, and familial features of the disease were incorporated into the criteria, subdivided into major and minor categories according to the specificity of their association with ARVC/D. At that time, clinical experience with ARVC/D was dominated by symptomatic index cases and sudden cardiac death victims-the overt or severe end of the disease spectrum. Consequently, the 1994 criteria were highly specific but lacked sensitivity for early and familial disease. Read More on PubMed
  • In patients with ventricular tachycardia (VT) and a history of myocardial infarction, intervention with an implantable cardioverter defibrillator (ICD) can prevent sudden cardiac death and thereby reduce total mortality. However, ICD shocks are painful and do not provide complete protection against sudden cardiac death. We assessed the potential benefit of catheter ablation before implantation of a cardioverter defibrillator. Read More on PubMed
  • Steam pops are a risk of irrigated radiofrequency catheter ablation (RFA) and may cause cardiac perforation. Data to guide radiofrequency (RF) energy titration to avoid steam pops are limited. Read More on PubMed
  • For patients who have a ventricular tachyarrhythmic event, implantable cardioverter-defibrillators (ICDs) are a mainstay of therapy to prevent sudden death. However, ICD shocks are painful, can result in clinical depression, and do not offer complete protection against death from arrhythmia. We designed this randomized trial to examine whether prophylactic radiofrequency catheter ablation of arrhythmogenic ventricular tissue would reduce the incidence of ICD therapy. Read More on PubMed
  • Implantable cardioverter defibrillators (ICDs) are life-saving devices in treatment of life-threatening arrhythmia. We evaluate the emotional status of Turkish patients with ICD and try to explain factors that affect emotional status of the patients. Read More on PubMed
  • Implantable cardioverter defibrillator (ICD) therapy is effective but is associated with high-voltage shocks that are painful. Read More on PubMed
  • The experiences of patients who received shocks from their implantable cardioverter defibrillator (ICD) and how these events affect their overall adjustment are poorly understood. Our goal was to evaluate quality of life and psychological well-being, and the prevalence of, and changes in, depression and anxiety of patients who did or did not experience defibrillatory shocks in the first 12 months after ICD implantation. In total 167 patients were monitored after discharge. Four self-administered questionnaires were used. The first assessment took place before ICD implantation, the remaining three at 1, 6 and 12 months after discharge. Read More on PubMed
  • The experience of shock is the distinguishing feature for patients with implantable cardioverter defibrillators (ICDs) and is associated with diminished psychological functioning and quality of life. Multiple shocks and ICD storm are a relatively common event among patients with ICDs (10-20%) and may present specific challenging medical and psychological management for the attending health care providers. This paper examines the medical and psychological aspects of ICD shocks and storms and describes a model of biopsychosocial management for patients following the experience of ICD storm. Successful management of patients post shock includes the use of antiarrhythmic medications and careful attention to the causality of the shocks via stored electrograms. The psychological management includes specific attention to debriefing post-shock feelings and attributions, preventing avoidance behavior, and facilitating positive "return to life" actions. Preliminary research examining formal psychosocial treatment supports a cognitive behavioral strategy to reduce psychological distress and facilitate quality of life. Collectively, these data suggest that interdisciplinary management of patients with multiple ICD shocks or the experience of ICD storm is advised, and routine psychological consultation may be indicated for the patient post ICD storm to reduce the possibility of symptoms of post-traumatic stress. Read More on PubMed
  • The purpose of this multicenter study was to evaluate the safety and efficacy of a radiofrequency (RF) catheter ablation system with internal saline irrigation. Read More on PubMed
  • Patients with implantable cardioverter-defibrillators often receive adjunctive antiarrhythmic therapy to prevent frequent shocks. We tested the efficacy and safety of sotalol, a beta-blocker with class III antiarrhythmic effects, for this purpose. Read More on PubMed
  • Although the effects of epicardial implantable cardioverter-defibrillator (ICD) leads on underlying cardiac tissue have been reported, the gross and microscopic changes associated with endocardial ICD leads are less well described. This study describes the gross and microscopic changes associated with endocardial ICD leads in humans. Read More on PubMed
  • The fatal outcome of victims after initially successful resuscitation from cardiac arrest has been attributed both to global myocardial ischemia during the interval of cardiac arrest and to the adverse effects of reperfusion. The present study was prompted by earlier experimental observation that the magnitude of myocardial dysfunction was in part related to the energy delivered during electrical defibrillation. Read More on PubMed