Sean Rodgers can feel his heart pounding during his marathon-training run - a reminder of how close to death he has come. The 43-year-old suffers from a dangerously abnormal heart rhythm that led, almost two years ago, to a cardiac arrest at his South Yorkshire home. It took 15 minutes for paramedics to shock him back to life using defibrillator paddles. 

Yet this spring, he plans to complete both the London and Edinburgh marathons, while pioneering a new life-saving technology, implanted in the skin under his arm. 

Implanted cardioverter-defibrillators (ICDs) have been used 

to jump-start dodgy hearts back into action since the 1980s. But Sean is one of the first patients in the UK to receive a radically new type of ICD that promises to transform the lives of the thousands of Britons at risk of abnormal heartbeat, called an arrhythmia (which is thought to have caused Fabrice Muamba, the Bolton footballer, to collapse on the pitch last month). 

Conventional ICDs have extended countless lives, but they have drawbacks, as reported on these pages recently. The battery-powered devices, implanted under the collarbone, monitor the heartbeat via wires that are passed through a vein into the heart. The wires pose a risk of infection and, because heart muscle moves constantly, there is also a chance of them fracturing and needing to be replaced, the surgery for which carries a further risk of damaging heart muscle and of infection. 

In addition, about one third of the shocks given by ICDs are triggered by variations in heartbeat that pose no immediate danger to the patient but can cause anxiety and panic attacks. 

The new state-of-the-art device, called the Subcutaneous Implantable Cardioverter-Defibrillator (S-ICD) is positioned in the chest area of skin under the arm. Unlike a standard ICD, the leads are not embedded in the heart but run just under the skin, outside the rib cage. Doctors say fitting the new

S-ICD is a simpler procedure, with less potential complications. The new device is also less likely to pick up harmless electrical “noise” from the heart and trigger distressing false alarms. 

“It doesn’t appear to give the false shocks that the old one did,” explains Dr Andrew Grace, consultant cardiologist at Papworth Hospital, Cambridge, who helped develop the device. “And it’s not touching the heart, so if an infection does occur, you can take it out without any problems.” 

Studies at Papworth and in New Zealand, published in the New England Journal of Medicine in 2010, found the S-ICD 100 per cent successful in treating severe arrhythmias. 

That’s exactly what Sean, a housing repair manager, discovered when he had a second cardiac arrest last November. 

“The S-ICD saved my life,” he says. “I got up off the sofa and could suddenly feel my eyes rolling into the back of my head. Then it went dark. The device must have kicked in - I was conscious again. According to the specialists, my heart stopped for only 17 seconds. I spent one night in hospital for a check-up – very different from my first attack.” 

More than 70,000 Britons die every year from sudden cardiac death triggered by an arrhythmia. After his first collapse in March 2009, Sean was in a coma for a week, and his wife, Maria, 47, and children, Liam, 16, and Emma, 13, were warned that it was unlikely he’d pull through. A marathon veteran, he had completed a 17-mile run days earlier. He had no idea there was a problem with his heart. 

Tests revealed that he had Long QT Syndrome, a condition affecting one in 10,000, where the heart takes longer than normal to reset its electrics after each beat. 

Unlike standard ICDs, the new type cannot act as pacemakers to help synchronise weaker hearts, so they are not suitable for all patients. However, Professor Peter Weissberg, medical director for the British Heart Foundation, said they may well prove cheaper for the NHS because fitting them is simpler and they are less problematic to maintain. 

Sean was the first patient at Sheffield Northern General hospital to have the £13,000 device fitted in January 2010, and one of just 1,000 patients worldwide. "It’s given me the confidence to get on with life," he says. 

"I haven’t had any false alarms, either. I run 30 miles a week now and ran a half- marathon recently. The device has given me the security of knowing that, if I need it, my heart will get a jump-start."