"It’s a miracle."

That's Dartford grandmother of six Frances Rodgers' conclusion after her life was transformed by a cutting-edge miniature, wireless pacemaker.

Frances, 70, was one of the first patients to have the new devices implanted in September 2016, in a last ditch attempt to treat her atrial fibrillation - a condition that causes an irregular and often abnormally fast heart rate.

Not much bigger than a grain of rice, the implant was fitted by surgeons at St Thomas’ Hospital in London - one of only three cardiac centres around the country to use the device, which is known as WiSE technology and developed by EBR Systems.

Unlike conventional devices, the innovative implant has no leads - which can be prone to failure - and is placed directly inside the heart tissue.

This makes it work more efficiently and over time the heart’s lining grows over it, so it becomes part of the heart.

Frances, from Shepherds Lane, Dartford, said: "I had another device fitted in 2000 but in 2015 I started to get very breathless so my doctor said I needed an upgrade which required another lead to be put in. But they couldn’t get it in because one of my heart valves had narrowed and although they tried their best, I was told nothing more could be done.

"By that point I was struggling to go up the steps to reach my front door and I was sleeping 18 hours a day. Then my doctor at Darent Valley Hospital told me that Professor Rinaldi was implanting a revolutionary device at St Thomas’, which I could have because it had no leads, and he put my name forward for it.

"I can’t believe how much difference the procedure has made. I’m not breathless, I sleep less, I can walk further and seeing friends and family is easier. It’s a miracle."

Experts at St Thomas' Hospital have worked with Siemens to create an image guidance system unique to the Trust which combines MRI (magnetic resonance imaging) and ultrasound imaging to create a detailed map of the heart. As a result, they can find the best place for the device to work as effectively as possible.

Professor Aldo Rinaldi, consultant cardiologist and professor of cardiac electrophysiology, said: "This type of device, known as a cardiac resynchronisation (CRT) device, is always placed inside the left ventricle which is the chamber that pumps oxygenated blood to organs around the body. Where we place it can affect how well it responds so our precise imaging system is very important. For example, some patients who have had a heart attack may have scarring inside the heart and the device won’t work well if it’s put there."

In order to implant the new device, patients first have a matchbox-sized generator implanted between their ribs, which sends out ultrasound impulses. In a separate procedure, a tube is inserted into an artery in the groin and is guided to the heart, where the device is positioned. It then converts the ultrasound waves into electrical pulses which keep the heart’s ventricles pumping in sync.

CRT devices synchronise the contraction of both sides of the heart. Conventionally they are placed under the skin in the upper chest and are linked to wires that feed into the right and left ventricles. But it is thought that around a third of patients do not benefit from them, with lead failures being the main complication.

Professor Rinaldi added: "The new device seems very promising for patients so far. At the moment it’s being used for patients who haven’t responded to conventional CRT devices or who can’t have a standard device, but if studies prove it is better then it could be used more widely in future."