Scar VF
Research type
Research Study
Full title
The personalised subcutaneous ICD vector: assessing recognition of ventricular fibrillation
IRAS ID
233594
Contact name
Benedict M Wiles
Contact email
Sponsor organisation
University Hospital Southampton NHS Foundation Trust
Duration of Study in the UK
1 years, 0 months, 31 days
Research summary
Implantable cardioverter defibrillators (ICD) are used to prevent sudden cardiac death in patients who are felt to be at risk of developing life threatening heart rhythms. They work by continuously analysing a patient's heart rhythm and shocking the heart if required. An entirely subcutaneous ICD (S-ICD) is now available. It has been demonstrated to be both safe and effective.
Ventricular fibrillation (VF) is a chaotic, fast and dangerous heart rhythm. To be effective, an implanted ICD must be able to quickly recognise VF such that life saving shock therapy can be delivered. The S-ICD records a patient's heart rhythm continuously, analysing the heart rate and seeking to identify VF. The sensing mechanism of the S-ICD has been shown to be highly effective.
However, the sensing mechanism employed by the S-ICD is not perfect and modifying this mechanism has numerous potential clinical advantages. These include increasing the number of people who can receive an S-ICD, improving the device's ability to distinguish between dangerous and non dangerous rhythms and also reducing inappropriate shock therapies.
It is vitally important that any alteration to S-ICD sensing does not alter the device's ability to detect VF. This must be tested clinically, using recorded examples of real life VF. Fortunately, many patients who receive an ICD, have a defibrillation threshold test (DFT) performed. This is a routine test during which VF is induced to test the device. A patient's heart tracing can be recorded during a DFT using simple ECG stickers attached to the patient's chest and limbs.
Recording a patient's heart tracing in this manner, allows real life recordings of VF to be made in a non invasive fashion. These recordings can then be used to facilitate testing of a new sensing mechanism, in a simulated environment, with no risk at all to patients.
REC name
London - Bromley Research Ethics Committee
REC reference
17/LO/1952
Date of REC Opinion
2 Nov 2017
REC opinion
Favourable Opinion