Arrhythmia is a heart rhythm abnormality. Now, this can either be due to the fact that
the heart is beating too slowly which is called a bradycardia or too quickly which is called
a tachycardia. The most common cause of bradycardia is intrinsic disease within the conducting
tissue of the heart. This is normally treated with a pacemaker. If your heart beats too
quickly, this called a tachycardia and the most common reason for a tachycardia is atrial
fibrillation. This diagnosis is prevalent in more than 5% of the population above 60
years of age and the most common risks that predispose patients to atrial fibrillation
include hypertension, diabetes or a previous history of a heart attack
If the arrhythmia is due to a slow heart rate or bradycardia, this is usually only resolved
with a permanent pacemaker implantation. If the arrhythmia is due to a tachycardia, the
most common of which is a diagnosis of atrial fibrillation, then there are several strategies
in a step wise manner that can be applied to treat the arrhythmia.
The first is to try and modify risk factors that provoke arrhythmia. This may be to do
with lifestyle changes treating obesity, treating diabetes, and hypertension. In patients who
continue to have frequent arrhythmic episodes, then drugs could be tried and in the case
where the drugs fail, then the option of catheter ablation, which is a specialised keyhole cardiac
surgical procedure, can be performed and selected individuals who fulfil the criteria. These
procedures are normally performed by a cardiac electrophysiologist in a specialised catheter
laboratory such as this.
A catheter ablation approach utilises an ablation
catheter such as this with a handle that allows very precise deflection of the tip of the
catheter and this is passed up through the femoral vein in your groin up to the heart.
Now, we have here a life size model of the heart - slightly larger than life size - where
you can see how we can navigate the catheter very precisely around regions of the heart
flexing onto the areas of the heart that are causing the arrhythmia to start up or fire
off from. We can then use radiofrequency energy which generates heat to destroy areas of tissue
that are causing the arrhythmia thus providing a cure for your arrhythmia. These procedures
are usually done in a catheter laboratory which has complex mapping equipment as you
can see behind me. These procedures are usually done by a cardiac electrophysiologist.
Here at Imperial College London, we have a very active research program looking into
the mechanisms of arrhythmia that underscore atrial fibrillation. We have developed with
our industry partners and charitable funders novel treatment strategies for atrial fibrillation
which includes an understanding of the heart rhythm abnormalities that are due to the nervous
supply of the heart or the autonomic nervous system.
There are other recent strategies that we focus on which includes the understanding
of the substrate or the tissue characteristics of the atria which promote atrial fibrillation
and this is done with 3D mapping technology in collaboration with our industry partners
to try and refine the ablation protocol to improve the cure and success rates for atrial
fibrillation for our patients