Trials are underway at a London hospital to treat a heart rhythm disorder by removing some of the heart’s nerve endings. The Royal Brompton Hospital is using the experimental treatment for Atrial Fibrillation, an irregular and often abnormally fast heart rate, which can affect people with cardiomyopathy. The procedure uses imaging to identify the locations of a branch of nerves, known as the sympathetic nervous system, that are thought to have a role in causing AF.
Radiofrequency energy is then used to destroy the nerve endings. This is done through catheter ablation. Thin, flexible wires are put into a blood vessel, often in the groin, and guided into the heart. A special machine sends the energy into the heart to treat small areas of heart tissue where the abnormal heartbeats are thought to originate.
AF is thought to affect up to 800,000 people in the UK and can cause palpitations, tiredness, breathlessness and dizziness. As the heart beats less effectively, it can lead to low blood pressure and blood clots that may cause a stroke.
In the trial, led by consultant electrophysiologist Dr Sabine Ernst at the Brompton, patients are injected with a dye and scanned with a high-resolution nuclear camera, called the D-SPECT. This shows up the areas in their hearts where the sympathetic nerves end.
The image from the nuclear camera is then merged with a standard 3D image of the heart from a CT scan and used as a guide during catheter ablation. The aim of the new Atrial Fibrillation Treatment is to adjust the activity of the sympathetic nervous system. Once the sympathetic nervous system works in a more balanced way with the parasympathetic side, AF is reduced.
The patients involved in the study will be followed up for 12 months, having regular tests including electrocardiograms (ECGs) to check their heart rhythms. After six months, the nuclear imaging scan is repeated to show how many areas of sympathetic nerve endings are still in the heart and how active they are.
The hospital says that one of the first patients treated on the trial was Tony Crook, a father of two from St Albans. The 55-year-old chartered accountant was diagnosed with AF in October 2014, after experiencing chest pains.
He had the trial treatment last month. Subsequent follow-up tests have showed that his heart is now in normal sinus rhythm and his six-month scan found that none of his sympathetic nerve endings are active in his heart anymore.
Tony said: “I’m really pleased I took part in the trial. It’s given me a new lease of life. I am completely drug free, and I am back enjoying life with peace of mind knowing that my children do not need to worry about me. This time last year I was at a very high risk of a stroke, which could have been devastating for my young family, but now that risk has totally disappeared.”
The pilot trial will involve 20 patients who have been diagnosed with AF. It is part-funded by Spectrum Dynamics, who make the D-SPECT camera.