INtra-procedural ultraSound Imaging During Pulmonary Veins Isolation
Condition: Atrial Fibrillation
MeSH terms: Atrial Fibrillation
Study type: Observational

Summary: 
      One of the biggest limitations of the currently used percutaneous techniques for Pulmonary
      Vein Isolation (PVI) in the setting of atrial fibrillation ablation is the lack of real-time
      information about the left atrial (LA) wall thickness and about its acute changes during
      energy delivery for ablation. This makes difficult to predict the achievement of transmural
      lesions, to identify the possible causes of ablation failure and also to avoid the occurrence
      of perforation and/or other collateral damage.

      Computed tomography (CT) is a reliable technique for measurement of the LA wall thickness but
      it cannot be used during the ablation procedure and its extensive use is limited by the need
      of ionizing radiation. Preliminary data from animal studies support the accuracy of real-time
      ultrasound imaging modalities such as intracardiac echocardiography (ICE) or Intravascular
      Ultrasound (IVUS) imaging for measurement of LA wall thickness and monitoring of its acute
      changes related to catheter ablation.

      The pilot study INSIDE PVs has been primarily designed to evaluate the feasibility and
      accuracy of intravascular imaging techniques for real-time imaging of the LA wall thickness
      during AF ablation.
    

Detailed description: 
      Patients scheduled for their first pulmonary vein (PV) isolation ablation for symptomatic,
      drug-refractory paroxysmal atrial fibrillation (AF), will be considered for inclusion in the
      study.

      Potential subjects will initially be approached some weeks before their ablation procedure,
      in order to give the patients enough time to consider the information, to ask questions to
      the Investigator, their general practitioner (GP) or other independent parties to decide
      whether they wish to participate in the study or not.

      For those interested in participation, a baseline assessment will be arranged to coincide
      with their standard pre-admission visit, for informed consent, screening and eligibility
      assessment. Moreover, a pre-operative imaging assessment with a cardiac computed tomography
      (CT) scan will be performed to define the LA and PV anatomy and to measure the baseline LA
      wall thickness and PVs ostial diameters.

      All AF ablation procedures will be performed in a standard fashion by using radiofrequency
      (RF) energy, cryo-balloon or laser balloon ablation under general anaesthesia and with
      continuous oesophageal temperature monitoring. Ultrasound imaging by IVUS (Visions PV .018,
      20 MHz digital probe, Volcano Corp) or ICE (Ultra ICE (9 MHz rotational transducer, Boston
      Scientific) will be performed at sites corresponding with the PV/LA junction at the beginning
      and the end of the procedure in order to measure acute changes in LA wall thickness and PV
      ostial diameters.

      The cardiac CT will be repeated within 24 hours post-procedure. After the procedure, a
      pre-discharge review and a telephone follow-up at 1 week will be performed to identify any
      early and late complications related to the procedure.

      A total of 12 patients will finally be enrolled in the study. The end of the study for each
      patient will be the date of the telephone follow-up 1 week after the procedure.

      For each patient the pre-procedural and post-procedural CT measurements of LA wall thickness
      and PVs ostial diameters will be compared with the corresponding IVUS or ICE measurements.
    

Intervention name(s): ICE/IVUS imaging during atrial fibrillation ablation
Intervention type(s): Procedure
Intervention description(s): Intravascular ultrasound imaging of the left atrial wall thickness with ICE/IVUS during atrial fibrillation ablation
Observational model: Case-Only
Time perspective: Prospective
Sampling method: Non-Probability Sample
Study population: 
        Patients scheduled for elective AF ablation in view of a history of symptomatic and
        drug-refractory paroxysmal AF.
      
Keywords: catheter ablation; intraprocedural left atrial wall thickness imaging