Non Invasive Mapping Before Ablation for Atrial Fibrillation.

RATIONALE / CONTEXT The ECG records the electrical activity propagating along cardiac cells (from the atria to the ventricles). The standard 12 ECG leads placed on the chest measure the global activation of the heart and do not have the ability to detect small-scale disturbances or to pinpoint ectopic activity. By the 1960s, multiple electrodes were placed around the chest to try to understand the complexity of the distribution of electrical activity in relation to the single cardiothoracic geometry of each individual. The safety of this method is similar to the ECG but its superiority has been demonstrated by the detection of anomalies imperceptible to the standard ECG. The accuracy of the technique in localizing rhythm disturbances is on the order of 5 mm.

OBJECTIVES Main objective: To evaluate the utility of noninvasive mapping during persistent AF electrophysiology procedure

Secondary objectives:

1. Compare the effectiveness of noninvasive mapping compared to conventional standard of care methods for AF mapping and ablation procedure.
2. Evaluate the absence of recurrence of persistent AF after a follow up of 12 months after the procedure during a scheduled hospitalization.

DIAGRAM OF RESEARCH European Diagnostic Study, feasibility, non-randomized, multi center

RESEARCH PROCEDURES A trained clinical specialist places 252 dry gelled ECG electrodes on the patient's torso. The 252 ECG electrode array is hooked up to the CardioInsight system and body surface ECG recordings are made during the patient's arrhythmia. The patient is then sent to the radiology department for a CT scan (no contrast) to image both the heart and electrodes on the patient's torso. A trained clinical specialist from CardioInsight then segments the CT DICOM images from the CT scan to obtain epicardial anatomy and establish heart-torso geometry.

The electrograms are processed by the system to produce movies of fibrillatory activity (both focal activity, and rotor activity).

PROCEDURAL ENDPOINTS Primary endpoint: Acute AF termination to atrial tachycardia or sinus rhythm

Secondary outcome criteria:

• Reduction in RF time compared to standard of care (historical control - comparable patient population)
• Reduction in procedure time compared to standard of care (historical control - comparable patient population)
• Freedom from persistent AF at the end of the 12 months F/U period STUDY SIZE

The sample size was estimated at 100 patients, with up to 20 patients per center STUDY CENTERS 8 Centers :

• Brugmann - Brussels (Belgium)
• Clinique Pasteur - Toulouse (France)
• Medizinische Klinik und Poliklinik - Mainz (Germany)
• University ed Herzzentrum Freiburg Bad Kozingen (Germany)
• Deutsches Herzzentrum München, Munich (Germany)
• Kerkhoff Klinik, Bad Nauheim, (Germany)
• Sint-Jan Sint-Franciscus Xaverius, Brugge (Belgium)
• Clinique Ambroise Paré, Paris, France

EXPECTED OUTCOME In patients referred for ablation of persistent AF, ECG mapping data will be correlated to the invasive procedure. It is expected that procedure time will be statistically shorter and total RF energy delivery is expected to be smaller than that of standard of care for AF treatment.