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