Arrhythmia: causes and types
The term arrhythmia describes a heart rhythm abnormality. 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.
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 stepwise manner that can be applied to treat the arrhythmia.
Treatment approaches for 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 on selected individuals who fulfil the criteria. These procedures are normally performed by a cardiac electrophysiologist in a specialised catheter laboratory.
A catheter ablation approach utilises a catheter 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. 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. These procedures are usually done by a cardiac electrophysiologist.
The latest developments in treatment
Here at Imperial College London, we have a very active research program which looks 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