Thousands of people with an irregular heartbeat could be cured thanks to a pioneering technique that uses a high-tech balloon.
British patients are the first to benefit from the procedure that is currently being trialled worldwide and UK doctors hope it could soon replace existing, more complex treatments.
Patients diagnosed with atrial fibrillation (AF) – the most common cause of abnormal heart rhythm – often get symptoms which can respond to surgery or drugs.
Thousands of people with an irregular heartbeat could be cured thanks to a pioneering technique that uses a high-tech balloon
The condition, which affects more than one million Britons, is triggered by abnormal electrical pulses in one or all four pulmonary veins leading from the lungs to the heart. These extra pulses over-ride the heart’s natural rhythm, causing it to beat abnormally fast and triggering symptoms such as palpitations, dizziness, shortness of breath and tiredness.
Diagnosis and treatment are vital because left untreated, AF can cause blood to pool in the heart rather than being pumped through, causing clots to form. If clots travel to the brain, they can block the blood supply, cause a stroke and also lead to heart failure.
Patients diagnosed with AF are usually prescribed medication to help control their heart rate and blood-thinning drugs to reduce the risk of clots.
Those with severe AF, or deemed unsuitable for medication, may be offered surgical intervention. Until now, there have been two main solutions.
The first involves freezing the pulmonary vein entrance, a procedure known as balloon cryoablation. This creates scarring, which blocks abnormal signals from the pulmonary veins and so helps maintain a normal heartbeat.
First, a tiny balloon measuring around 28mm is threaded from a 4mm incision in the groin to the entrance of each pulmonary vein.
British patients are the first to benefit from the procedure that is currently being trialled worldwide and UK doctors hope it could soon replace existing, more complex treatments
Once in position – touching the vein entrance – the balloon is cooled to minus-40C using nitrous oxide gas.
Then, in several minute-long bursts, the vein walls are frozen until a monitor connected to the balloon shows abnormal electrical signals have been blocked.
This is repeated for each pulmonary vein.
But, says Professor Richard Schilling, consultant cardiologist at Barts Health NHS Trust in London: ‘Results can be variable due to the back part of the pulmonary vein being thinner than the front. Freezing it all equally means that some areas don’t get enough treatment, while others are overtreated.’
A second treatment, called radiofrequency catheter ablation, involves burning a ring of dots around the vein wall that forms scar tissue to block abnormal electrical pulses.
Patients diagnosed with atrial fibrillation (AF) – the most common cause of abnormal heart rhythm – often get symptoms which can respond to surgery or drugs
However, this has only been available to a relatively small number of patients due to the complexity of the procedure.
The new technique being trialled at St Bartholomew’s Hospital is called radiofrequency balloon ablation, and is a combination of the two methods.
It involves a balloon fitted with ten electrodes delivering precise doses of heat to tissue around the pulmonary vein entrances to prevent rogue electrical signals.
‘It targets all the vein wall at the same time rather than destroying individual bits of tissue one after the other,’ explains Prof Schilling.
‘We can adjust the power and duration of burn to suit the thickness of tissue under each electrode. More resistant areas can be treated more than once, without moving the balloon, by switching electrodes on or off.
The condition, which affects more than one million Britons, is triggered by abnormal electrical pulses in one or all four pulmonary veins leading from the lungs to the heart
‘This allows us to adjust treatment for each patient and really is a game-changer – reducing average operation times from three hours to less than 90 minutes.’
‘Initial follow-up data of patients shows they have all been hugely improved. They’ve been able to come off medication and are symptom-free.’
He hopes the next stage of the trial – treating 30 more UK patients and 50 worldwide – will provide evidence for the treatment to be made routine for AF. Prof Schilling says: ‘We also hope the relative simplicity of this technique means more cardiologists can train to perform it, allowing more patients to receive this vital treatment.’
Dr Douglas Newberry, 67, a lung specialist at Princess Alexandra Hospital in Harlow, Essex was one of the first patients to benefit from the new technique.
These extra pulses over-ride the heart’s natural rhythm, causing it to beat abnormally fast and triggering symptoms such as palpitations, dizziness, shortness of breath and tiredness
After suffering symptoms four years ago, he was diagnosed with Paroxysmal AF (PAF) – a variant of the condition that goes away spontaneously or without intervention in less than a week, but returns.
‘I didn’t feel quite right and had a little discomfort after doing a vigorous step class,’ says Dr Newberry, a fit, non-smoker.
Tests showed he did not have narrowed arteries and was prescribed Flecainide, a blood thinning drug used for AF. He adds: ‘Then, about two years ago, episodes began to last longer, more frequently and at any time. I didn’t finish an exercise class for the first time. I would take the lift rather than stairs and twice I had to sit down as I felt dizzy standing.’
After a referral to Barts, Dr Newberry was offered the new treatment by Prof Schilling.
‘He said, “We’re trying out a new way of doing this”, and I thought he is one of the top guys in the world so let’s go for it!
‘I felt slightly unwell for four to six weeks, and since then I’ve felt fine.
‘I’ve spent my life working in the health service and I’ve received outstanding service from my GP to Barts.’