Mapping heart signals to help atrial fibrillation sufferers
9 February 2010
Scientists at the University of Leicester are creating maps of
irregular signals of the heart in an innovative project that has
potential to bring benefits for millions of people who suffer from
irregular heart rhythm.
An estimated 4.5 million people in the European Union are known to
have atrial fibrillation (AF) — the most common type of arrhythmia or
abnormal heart rhythm. The condition affects about 10% of people over
the age of 70. Considering the advancing age in the general population
and links to body size and obesity, scientists say the increase in AF is
almost approaching epidemic proportions.
Researchers from the Department of Engineering at the University of
Leicester are working with colleagues in the University’s Department of
Cardiovascular Sciences and St Jude Medical UK to devise a new way of
‘mapping’ the electrical signals of the heart and creating a colour map
of abnormal signals. This will allow cardiologists to target them with
University of Leicester scientists Dr. André Ng (Cardiovascular
Sciences) and Dr. Fernando Schlindwein (Engineering) were recently
awarded a grant in excess of £63,000, to pursue research on the
diagnostic and treatment of atrial arrhythmias by the Engineering and
Physical Sciences Research Council.
Additionally, Dr Schlindwein has also been awarded an industry
secondment by the Royal Academy of Engineering, worth £15,000, for the
same collaborative research involving St. Jude Medical UK and
Departments of Cardiovascular Sciences and Engineering at the University
Atrial fibrillation (AF) is the most common type of arrhythmia or
abnormal heart rhythm. The condition involves the left and right atrial
chambers of the heart and is characterised by quivering or
‘fibrillating’ of heart muscles, instead of the usual coordinated
AF is currently treated using strategies that either slow the heart
rate or revert heart rhythm to normal. Surgical and catheter-based
therapies are also used in certain individuals, but these procedures
pose a certain amount of risk to the patient.
Dr. Schlindwein says, “A catheter is a very thin tube that is
inserted in the patient’s femoral vein (usually) and guided into the
patient’s heart, wherein it can record from or deliver electrical
signals to the heart. The ablation catheter delivers high-energy
radiofrequency waves to ‘burn’ and kill the cells that are responsible
for the heart rhythm disturbance once identified”.
Dr. Ng performs catheter ablation procedures including that for AF at
Glenfield Hospital, Leicester, which is one of the largest cardiac
electrophysiology centres in the UK.
Dr Ng says, “Catheter ablation is a new and effective treatment aimed
at ‘curing’ patients of AF. Patients referred early in the disease
respond very well to the procedure whilst others with more advanced form
of the condition respond less well. Much research effort is currently
focused on improving the success and safety of the procedure with the
least amount of ‘burning’ and best outcome.”
Dr Ng is also an expert in the use of state-of-the-art non-contact
multi-electrode array catheter for 3-dimensional mapping of the heart to
facilitate ablation and is director for pan-European training courses
for this technique.
Dr Ng and Dr Schlindwein’s research aims at improving current
techniques by using the non-contact array catheter to detect and map
cardiac electrical signals during AF ablation. On account of its
‘non-contact’ nature, it is possible to map signals more accurately
using this strategy.
Dr Schlindwein explains, “This technique essentially enables us to
identify regions of the heart which shows the best promise of a good
outcome with ablation. Regions of the heart showing abnormal signals can
be visualised using a real-time colour map superimposed to the
three-dimensional representation of the atrium. This allows us to pick
targets for ablation with unprecedented accuracy”.
Dr Ng and Dr Schlindwein's collaborative work thus makes a stark
improvement on the existing technique by incorporating more
sophisticated and near ‘real-time’ signal analyses, which significantly
increases chances for successful ablation therapy. Importantly, they
expect that these approaches can potentially reduce the need for a
second procedure, which is significant given the inherent risk of the