Subclinical TWOS and ECG Predictors (STEP Study)
Research type
Research Study
Full title
Identification Of Subclinical T-wave Over Sensing By The Subcutaneous Internal Cardioverter Defibrillator and Electrocardiographic Criteria Which Predict Risk: A Single Centre Case-Control Study
IRAS ID
200844
Contact name
Benedict M Wiles
Contact email
Sponsor organisation
University Hospital Southampton NHS Foundation Trust
Duration of Study in the UK
1 years, 9 months, 1 days
Research summary
Implantable cardioverter defibrillators (ICDs) are used to prevent sudden cardiac death (SCD) 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. This ICD does not enter the heart or blood vessels but sits under the skin. It is still able to recognise and treat dangerous heart rhythms and prevent SCD. It has been demonstrated to be both safe and effective and is now widely available.
A significant problem with ICDs is inappropriate shocks (IAS). This is where a patient receives shock therapy when they are not in a life threatening heart rhythm. This can be associated with physical, psychological and emotional stress. It is important to reduce the risk of IAS as much as possible in the ICD population. In patients who have an S-ICD, the most common reason for IAS is the device incorrectly interpreting heart signals, a malfunction called T-wave over sensing (TWOS).
This study will identify patients with an ICD and perform a combination of resting heart traces (ECGs) and 24 hour heart monitors (Holters) to both look for TWOS, and to identify which patients are at greatest risk of experiencing this complication. We believe that certain ECG findings increase risk of TWOS and are hoping to assess this further. The overall aim in to further our understanding of TWOS and reduce the risk of IAS for S-ICD patients.
REC name
London - Brent Research Ethics Committee
REC reference
16/LO/0534
Date of REC Opinion
22 Mar 2016
REC opinion
Favourable Opinion