The electrics of the heart
The ‘spark’ who looks after our hearts
When it comes to matters of the heart André Ng is the electrician.
As a Professor of Cardiac Electrophysiology, and a Consultant Cardiologist and Electrophysiologist, his work focuses on the electrics of the heart, the messages that go between the heart and the brain, and what controls them. If those messages don’t get through our hearts can start beating erratically or suddenly stop beating altogether.
The good news is that the field of sudden cardiac death and atrial fibrillation (AF) has moved on swiftly in the last 10 to 15 years so most broken hearts can be mended. Professor Ng said: “Ways to fix a heart are at our finger tips for the vast majority of patients. We are doing life changing stuff every day. A lot of new things are happening and all for the common good of improving patient outcomes.”
But, despite these advances, around 100,000 people in the UK still die every year as a result of sudden cardiac death.
As well as heading up the Department of Cardiovascular Sciences, Professor Ng leads a research team working on sudden cardiac death prevention and prediction, and atrial fibrillation mechanisms. They hold two patents on technology that is currently being developed to predict sudden death risk. It has the potential to save thousands of lives.
What causes the electrics to fail?
Heart rhythm disturbances occur when the electrical impulses that coordinate the heartbeat don’t work properly. This can happen in patients of all ages from teens to centenarians.
Professor Ng sees young patients with Supraventricular Tachycardia (SVT) – an electrical short-circuiting of the heart that can cause palpitations.
Cardiac ablation procedures can fix arrhythmias and restore a regular heart rhythm. Tens of thousands of these procedures are carried out every year. Professor Ng says this technique has transformed health care. “We burn away a bit of heart tissue to correct the electrical signals and they don’t have the problem again, which is literally a cure for many patients.”
If the heartbeat slows a pacemaker can be fitted. Professor Ng said: “Before the pacemaker was first developed patients were dying in front of our eyes. You put a pacemaker in and you see a patient coming back to life. We don’t stop at any age for pacemakers.”
High-risk patients are fitted with an Implantable Cardioverter Defibrillator ICD) which will charge up and shock the patient if their heart stops. But only 40 out of every 100 ICDs ever get used so 6 out of 10 devices are implanted without the need for them. The difficulty is predicting which patients are at risk.
Predicting sudden cardiac death
Professor Ng has developed two markers that could predict which patients are at risk of sudden cardiac death. It is the culmination of a decade of research.
Together with the late Professor John Coote, he identified a property of the heart muscle called ‘electrical restitution’ – a dynamic of the heart’s electrical system that can determine how easy it is for abnormal rhythms to occur.
Based on this discovery an interdisciplinary team at the University of Leicester, led by Professor Ng, is in the process of developing award winning technology called LifeMap™. The potential for this technology has been recognised with a Da Vinci Award, a Medical Futures Innovation Award 2011 and the European Heart Rhythm Association Inventors Award 2016.
Professor Ng said: “There is no other tool like this. It is addressing a major clinical gap in identifying patients who are at risk of sudden death. A lot of these patients will die if there is no one nearby.”
Using a wire inserted into the groin and up into the heart this new measurement has already been embedded into ECG recordings. The next job is to make it into a much more user-friendly tool.
The team have been awarded funding of over £1m from the Medical Research Council’s (MRC) Developmental Pathways Funding Scheme. Professor Ng is working with Dr Fernando Soares Schlindwein a Biomedical Engineer in the School of Engineering at the University of Leicester and Dr Will Nicolson at the University Hospitals of Leicester NHS Trust to develop a non-invasive, treadmill test. As soon as that is done it will be applied to a large clinical study.
What lies on the horizon?
AF affects one in 10 of people over 70 increasing their risk of stroke five fold. Whilst ablation is effective in AF patients when diagnosed early, it proves to be more challenging in more advanced stages of the disease.
He said: “Atrial fibrillation has really opened our eyes to what we can really do. In the next five to ten years we will see a lot better treatment of AF. Things have moved very rapidly over last 10-15 years and we will see this continue over next decade or so.
“We are using new tools every day in the drive to do things better, faster and safer.”
What can we do to look after our hearts?
When it comes to looking after our hearts Professor Ng says be sensible and strike the middle ground. Eat healthily and do things in moderation. Doing nothing is bad – doing something in moderation is probably the best way to keep the heart healthy. He said: “Exercise is good for the heart and being active is healthy, but doing too much might not be that wise. Sports fanatics put a lot of demand on the heart and we see a lot of young people developing heart rhythm problems because of that.” Rest, he says, is also important.