Tiny wire basket that stops your heart beating too fast
AROUND 600,000 Britons have abnormal heart rhythms, including atrial flutter. Rod Stapley, 65, a retired youth justice manager from Newcastle, was one of the first to undergo a new procedure to treat it, as he tells CAROL DAVIS.
DUrINg routine tests before an operation for a collapsed disc in my back in may 2015, doctors asked if I knew I had an irregular heartbeat. Apparently the ECg, which measures the electrical activity of my heart, had revealed that the upper chambers of it were beating too fast.
I was initially quite shocked because I didn’t think I had any symptoms. but now, looking back, I realise I’d started to cycle less over the previous year because it had become too difficult. I’d always blamed my back pain.
Doctors said I had atrial flutter, which means the top chambers beat much faster than the bottom ones because of problems with the electrical signals in my heart.
I was prescribed beta-blockers to slow my heart and warfarin to ward off the chance of a blood clot, but my cardiologist said I’d need a procedure to fix the faulty signals at some point.
After I recovered from back surgery six months later, as I became more active again I noticed myself getting breathless even when doing a weekly shop.
my cardiologist recommended I have cardioversion, where they give your heart a shock to send it back into normal rhythm. I had that in November 2015 and it seemed to work.
but around six months later, while on holiday with my wife lin and our family, my breathlessness returned. Instead of hiring a bike like I’d planned, I felt totally lethargic and just lazed all day, watching my two grandchildren playing — it was annoying not to be running around with them. When I got back home my cardiologist said I now needed ablation, where they burn the area of the heart that’s triggering abnormal signals. I was referred to the Freeman Hospital in Newcastle, and went there in December.
The cardiologist explained he was trialing a new device called AcQmap which made ablation more accurate so it was less likely I’d need to have it done again (Apparently in half of patients it has to be repeated because it doesn’t work first time.) He said it is a hand-held probe, like a wire basket, studded with tiny ultrasound ‘crystals’, that help create a precise image of the heart which doctors use to know where the faulty signals are coming from.
I had the four-hour procedure under local anaesthetic and sedation last December. It was fascinating to watch the images of my heart in real-time on a screen next to me. About 90 minutes in, they increased the sedation so I don’t remember anything else. I woke up feeling groggy, but went home that evening. Next morning I was full of energy and went for a walk with my dog Des. The breathlessness had disappeared.
Now I’m back to cycling and seven-mile walks at weekends. I can run around with my grandchildren, too, which feels great.
THE SPECIALIST
Dr Steve Murray is a consultant cardiologist at the Freeman Hospital in Newcastle. AbNormAl heart rhythms make most patients feel tired, breathless and lethargic because not enough blood is pumped around the body.
Normally the heart beats in response to an electrical signal sent from the sinus node in the heart’s top right chamber (the right atrium), which spreads down to the lower chambers (ventricles).
In atrial flutter, the signals take an abnormal route through the heart and the top chambers beat too fast. It’s like driving a car stuck in third gear, which is too fast for resting and too slow for exercise. This can wear the heart out and lead to heart failure — where the heart can’t supply enough blood to vital organs — and blood can stagnate in crannies of the heart and clot, potentially leading to heart attack or stroke.
We can prescribe beta-blockers to slow the heart rate and warfarin to thin the blood so clots are less likely. If these aren’t enough we offer cardioversion, which resets the heart using an electric shock.
If that doesn’t help, next we use catheter ablation, where we burn lines of scar tissue in the atrium to block these abnormal electrical signals, restoring normal rhythm.
We do this using a flexible tube (catheter) with an electrode on the end. We can use the same or different electrodes to map the heart first to create an image — but currently this involves touching the walls of the atrium to create a map.
Touching the heart could change the rhythm by blocking it or switching it off temporarily, which may be why this technique succeeds in one patient but not the next. Quite often it works the first time, but half of patients need it done again.
The image with standard ablation is also not very detailed, so we could potentially burn away healthy tissue, too.
but a new device, AcQmap, which was developed in the U.S., lets us map the heart during the procedure and creates a detailed image which we use as a guide for more accurate ablation.
We also don’t need to touch the heart tissue at all as it uses ultrasound to produce the image.
AcQmap looks like a round basket made of wire which is studded with crystals and electrodes. The crystals emit ultrasound signals that gauge the shape of the heart while the electrodes pick up where the faulty impulses are coming from.
The data is fed into a computer that creates a very detailed image of the heart which we use to guide the ablation device. The procedure takes around four hours under general anaesthetic or sedation.
First we make four tiny punctures in the vein at the top of the groin. We insert two long tubes and feed them into the right atrium, then slide the ablation device and the AcQmap device through each tube.
We activate the AcQmap first to create the image and we then activate the ablation device.
When we’re done, we use AcQmap to check the heart has returned to normal rhythm. If not, we do it again.
Then we withdraw all the tools and seal the punctures by putting pressure on them for 15 minutes; they don’t need bandages.
The patient can leave soon afterwards — most will feel a difference immediately.
Patients take blood-thinning medication for the first 12 weeks but most won’t need it after that.
Using AcQmap makes ablation more accurate and gives us a higher success rates because we tailor it to the individual patient.
tHe procedure costs the NHS around £3,500, and £8,000 if done privately.