CASDAF-HD

  • Research type

    Research Study

  • Full title

    Characterising the stable and dynamic left atrial substrate in atrial fibrillation using high density contact and non-contact mapping

  • IRAS ID

    255290

  • Contact name

    Tim Betts

  • Contact email

    tim.betts@ouh.nhs.uk

  • Sponsor organisation

    Oxford University Hospitals NHS Foundation Trust

  • Clinicaltrials.gov Identifier

    NCT04229472

  • Duration of Study in the UK

    2 years, 0 months, 0 days

  • Research summary

    Atrial fibrillation (AF) is the most common sustained arrhythmia with increasing prevalence associated with an ageing population. Management is challenging, and invasive catheter ablation procedures are increasingly used in those with symptoms refractory to drug therapy. Unfortunately, success rates from this procedure can be limited. This is partly due to limitations in our understanding of the mechanisms involved in arrhythmia propagation. There is much interest in the role of structural changes within the muscle of the left atrium resulting in scaring (known as fibrosis). This has been identified on MRI studies and invasive electroanatomical mapping uses voltage amplitude of recorded signals as a surrogate measure of tissue properties. This however is affected by the technology used as does not routinely incorporate the effect of heart rate on conduction properties. Furthermore, although this aims to identify regions of structural changes, it does not identify more dynamic patterns of conduction seen during AF.
    This study aims to use a high density mapping catheter (Abbott Advisa HD grid (SE)), which employs a novel algorithm to minimise the effect of wavefront direction on the size of electrical signals. We aim to conduct electroanatomical mapping of the left atrium in patients with atrial fibrillation whilst pacing at long and short cycle lengths to assess the effect of pacing rate on conduction properties, assessed using signal morphology and conduction velocity. The same procedure will also be carried it in 5 control patients to allow comparison with normal atria. 2 subgroups will also analysed. In the first we aim to compare the use of the HD grid catheter to a bipolar ablation catheter in carrying out electroanatomical mapping. In the second, we will correlate electrical signals obtained with propagation patters identified using the AcQMap non-contact mapping system and atrial properties identified on cardiac MRI.

  • REC name

    London - Surrey Research Ethics Committee

  • REC reference

    20/LO/0150

  • Date of REC Opinion

    25 Mar 2020

  • REC opinion

    Further Information Favourable Opinion