Ultra-high Density Mapping With Multielectrode Catheter vs Conventional Point by Point Mapping for Ventricular Tachycardia Substrate Ablation

Study Overview
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Brief Summary
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Ultra-high density mapping with multielectrode catheter may improve slow conduction channels identification in ventricular tachycardia substrate ablation procedures compared to conventional point by point mapping. This study compares the ability of both mapping catheters to detect slow conduction channels in areas of myocardial scar and their utility to assess substrate modification after ablation.

Detailed Description
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This is a prospective, randomized controlled study. Twenty patients with sustained ventricular tachycardia and structurally abnormal ventricle(s) will be prospectively enrolled. In all patients a detailed pre and post-ablation electroanatomical mapping will be performed, and these maps will be merged with CT and/or MRI images. Patients will be randomly assigned to two groups. In Group A patients both pre and post-ablation mapping will be performed firstly by conventional point by point mapping using a Navistar Thermocool catheter, and secondly by multielectrode contact mapping using a Pentaray catheter. In this group, target ablation sites will be guided by point by point map. In Group B patients, both pre and post-ablation mapping will be performed firstly by multielectrode contact mapping using a Pentaray catheter, and secondly by conventional point by point mapping using a Navistar Thermocool catheter. In this group target ablation sites will be guided by multielectrode contact mapping. Slow conduction channels will be identified by color-coded voltage map adjustment of the lower and upper thresholds and also the presence of fractioned electrograms with the delayed component showing sequential orthodromic activation. The entrances of these channels will be the target of the ablation sites (scar dechanneling technique).

Official Title
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Ultra-high Density Mapping With Multielectrode Catheter vs Conventional Point by Point Mapping for Ventricular Tachycardia Substrate Ablation

Conditions
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Ventricular Tachycardia

Intervention / Treatment
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* Device: Ablation guided by conventional mapping.
* Device: Ablation guided by ultra-high density mapping with multielectrode catheter.


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Patients with indication for ventricular tachycardia substrate ablation. Exclusion Criteria: Pregnant woman. Reduced expectancy of life (less than 12 months) Patient participating in another clinical study that investigates a drug or device Psychologically unstable patient or denies to give informed consent Any cause that contraindicate ablation procedure or antiarrhythmic drug

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Conventional Mapping<br>Both pre and post-ablation mapping will be performed firstly by conventional point by point mapping using a Navistar Thermocool catheter, and secondly by multielectrode contact mapping using a Pentaray catheter. In this group, ablation will be guided by conventional mapping. | Device: Ablation guided by conventional mapping.<br>* Substrate mapping and ablation of ventricular tachycardia.<br>|
| Other: Multielectrode mapping.<br>Both pre and post-ablation mapping will be performed firstly by multielectrode contact mapping using a Pentaray catheter, and secondly by conventional point by point mapping using a Navistar Thermocool catheter. In this group ablation will be guided by multielectrode contact mapping. | Device: Ablation guided by ultra-high density mapping with multielectrode catheter.<br>* Substrate mapping and ablation of ventricular tachycardia.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Mapping and ablation times | Mapping and ablation times with each mapping system (point by point vs multielectrode mapping). | During procedure. | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Scar area correlation with MRI. | To assess the correlation between the values of scar area obtained from both electroanatomical mapping systems and those resulting from the analysis of MRI. | Immediately after intervention. | 
| Radiofrequency delivery time. |  | During procedure. | 
| Reduction of residual electrograms with delayed component. | Reduction of residual electrograms with delayed component after ablation. | Immediately after intervention. | 
| Ventricular tachycardia inducibility after ablation. |  | Immediately after intervention. |