Identifying and assessing the risk of recurrent stroke in patients with atrial fibrillation and cardiac ultrasound findings
Atrial fibrillation (AF) is the most common type of irregular heart rhythm, and happens when, in addition to the heart’s natural pacemaker, other areas of the heart make electrical impulses too. Instead of a co-ordinated beat, part of the heart twitches, which can allow blood clots to form. These clots can travel through the bloodstream and can cause a stroke or TIA.
The prevalence of AF increases with age, and can either be present and therefore easily detected all the time (permanent), or comes and goes (paroxysmal). People diagnosed with AF are usually treated with blood thinning medication (anticoagulants), but the relevance of brief episodes of paroxysmal AF detected shortly after TIA or minor stroke and the subsequent stroke risk is uncertain.
This project involves fitting all patients attending an emergency TIA and minor stroke out-patient clinic with a five-day R test monitor, which is repeated at one year.
In addition, we also look for small structural changes in the heart, which can either be present from birth or develop later in life, which can also cause clots to form. These can be seen by a simple ultrasound scan of the heart, called an echocardiogram.
The recordings from the R test are then reviewed to identify the presence, length and frequency of any episodes of AF and any abnormalities seen on the echocardiogram. From this information we can answer questions such as:
- what is the short and long term risk of recurrent stroke in patients who had brief paroxysmal AF (pAF) on 5-day monitoring?
- do very brief episodes of pAF progress to longer episodes over time?
- can the progression of pAF to permanent AF be predicted from the results of the echocardiogram?
This project is coordinated by the Centre for the Prevention of Stroke and Dementia www.stroke.ox.ac.uk.
