MANual vs. automatIC Local Activation Time Annotation for Guiding Premature Ventricular Complex Ablation (MANIaC-PVC)

MANual vs. automatIC Local Activation Time Annotation for Guiding Premature Ventricular Complex Ablation

MANual vs. automatIC Local Activation Time Annotation for Guiding Premature Ventricular Complex Ablation Procedures (MANIaC-PVC Study). A Randomized, Multicenter Study

Current navigation systems incorporate algorithms for automatic identification of local activation time (LAT). However, data about their utility and accuracy in premature ventricular complex (PVC) ablation procedures are scarce. This prospective, randomized study analyzes the accuracy and effectivity of an algorithmic method based on automatic annotation of the maximal negative slope of the unipolar electrogram within the window demarcated by the bipolar electrogram, compared with conventional, manual annotation during PVC ablation procedures.

This is a prospective, randomized, controlled and international multicenter study. The investigators aim to analyze the accuracy of LAT annotation using a novel algorithmic method (Wavefront, CARTO, Biosense Webster, Diamond Bar, California, USA) (WF), based on automatic annotation of the maximal negative slope of the unipolar electrogram (U-EGM) within the window demarcated by the B-EGM, by comparison with conventional, manual annotation in a multicenter cohort of patients referred for PVC ablation. Further on, the automatic annotation of LAT will be aided by an ECG recognition pattern algorithm (included in the last version of CARTO), which is intended to avoid wrong annotation of ventricular complexes other than the clinical PVC. The investigators hypothesize that automatic LAT annotation (using WF and the ECG recognition algorithm) could be superior to conventional, manual annotation in terms of mapping success and could reduce both procedure time and radiofrequency time.

This is a prospective, randomized, controlled and international multicenter study. All patients who fulfill the inclusion criteria will be consecutively enrolled and randomized on a 1:1 basis to each of the LAT annotation systems (WF vs. M-method) before the ablation procedure. Ablation will be directed to the earliest activation site identified with the assigned annotation system. Any change of the assigned annotation system during the procedure won't be allowed, thus being a reason for justifying study exclusion.

The annotation of LAT in each acquired point will be automatically performed using the LAT annotation tool integrated into CARTO navigation system, called Wavefront (WF). Automatic annotation of LAT performed by the CARTO system uses the maximum negative slope of the distal U-EGM to set the timing of the mapping annotation, displayed on the corresponding B-EGM. Additionally, the automatic annotation of LAT will be aided by an ECG recognition pattern algorithm (included in the last version of CARTO), which is intended to avoid wrong annotation of ventricular complexes other than the clinical PVC.

A detailed electrocardiogram (ECG)-gated activation map of the chamber of interest will be acquired using the CARTO navigation system. An experienced electrophysiologist will perform the annotation of LAT in each acquired point. The LAT will be measured from the onset of B-EGM (earliest positive or negative deflection) of the distal dipole of the mapping catheter to the defined reference. The use of the U-EGM as a guidance to identify the real onset of B-EGM will be decided under electrophysiologist criteria.

Automatic annotation of LAT during PVC activation mapping. Acquisition of points will be automatically performed using the Wavefront (WF) annotation tool integrated into CARTO navigation system.

Conventional, manual annotation of LAT during PVC activation mapping. Acquisition of points will be performed using the CARTO navigation system by an expert electrophysiologist.

Rates of mapping success, using the assigned mapping approach (automatic vs. manual), as defined in description

Mapping success will be defined as complete PVC abolition after RF applications at the earliest activation site (EAS) identified using the assigned mapping approach. A maximum of 2 RF applications with appropriate parameters (contact force, impedance drop, catheter stability) during a maximum of 45 seconds will be allowed. If the PVC is not abolished after 2 RF applications with appropriate parameters, mapping will not be considered successful.

In the case of PVCs arising from ventricular outflow tracts, we propose an algorithm to avoid subjective criteria, and to deal with eventual wrong selection of the first mapped chamber, leading to unnecessary RF applications. This algorithm involves a step-by-step analysis of the PVC-ECG morphology: precordial R/S transition and presence of one or more of the following clinical items, which have been previously related with a left origin: male gender, hypertension, or age > 50 years.

Target point is defined as any suspected PVC-site of origin where RF is delivered according to mapping data. Therefore, for one case there can be found a single target point with multiple RF applications, or multiple target points with one single RF application. The maximum distance between 2 RF applications to be considered at the same target point will be defined as 5 mm (equivalent to a 1-cm2 area).

Inclusion Criteria: Age > 18 years. Indication for PVC ablation. Signed informed consent. Exclusion Criteria: Age < 18 years. Pregnancy. PVC ablation procedures guided by pace-mapping (PASO® module); eg. low burden of PVCs during the study, mechanical impact during activation mapping. Impossibility to perform activation mapping with the required density of points in the region of interest (see section 4.5.3). Concomitant investigation treatments. Medical, geographical and social factors that make study participation impractical, and inability to give written informed consent. Patient's refusal to participate in the study.

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