Hospital doctor Míde Duff considers herself lucky to be enjoying a full, active life, despite having a complex congenital heart condition that became apparent only when she was born an alarming blue colour.
“I was obviously clearly very unwell and they didn’t know what was wrong with me. Then [they] quickly realised that I had a heart condition,” she says of what she has heard about her birth at the National Maternity Hospital in Holles Street, Dublin, 35 years ago. Her condition is known as transposition of the great arteries – one of the rarer forms of congenital heart disease (CHD).
“I describe it as a plumbing problem of the heart. Effectively, it’s a condition whereby, when I was born, the deoxygenated blood that was meant to go to my lungs was going around my body, and the oxygenated blood was going to my lungs. You need surgery, or else you won’t survive.”
As a newborn, she had a procedure to allow mixing of the blood flow to keep her stable until her heart became a bit bigger. When she was 10 months old, the late, pioneering cardiac surgeon Maurice Neligan did open-heart surgery on her in the children’s hospital in Crumlin.
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The Senning/Mustard procedure involved rerouting of the blood flow of her heart. There are two chambers in the heart and normally the bigger one pumps blood around the body. In Duff’s case, the surgery had to permit rearranging for the smaller chamber to pump the blood.
“I have got reduced heart function, but, despite that, the surgery went very well. I’ve done very well as a child into adulthood.”
Currently working in Scotland, she plans to return to Ireland to specialise in medicine for the elderly.
One big challenge Duff had to overcome happened in her teenage years. By then the family had moved from Leixlip, Co Kildare, to Dungarvan, Co Waterford, where she had a “very outdoorsy, active” childhood, growing up as the middle child between Deirdre, her elder sister and April, the youngest.
“I was always racing around the place with my sisters and involved in lots of sports, athletics and Gaelic games and hockey. I was good at sports and, as you get into teenage years, sports become very competitive and a bit more serious.”
As a member of West Waterford Athletic Club, she had won underage medals at county, provincial and national level. But, on the advice of her cardiologist, Duff’s parents had to pull her out of competitive sports. “It was terribly upsetting for me at the time,” she says. “When you’re young, your friends are there – you don’t see the bigger picture.”
She tried some other sports, which again she had to be withdrawn from, until she settled on tennis at the local club in Dungarvan. “That’s just somewhat less demanding. I was very happy and did well in that. You just move on.”
[ All-island children’s heart surgery now world class, say doctorsOpens in new window ]
An estimated 500-600 babies are born in Ireland with CHD every year. These conditions range from what are now considered simple cases, such as a hole in the heart or valve-narrowing, to complex cases such as a single pumping chamber, arteries joined together or reversed, or a combination of valve-narrowing plus a hole in the heart. Up to 70 per cent of diagnoses are made at the 20-week maternal scan. However, some cases may not be picked up until well into adulthood – sometimes in the course of investigations for something else.
The amazing thing about the heart is that, as it is built for exercise, it has a great reserve, says cardiologist Prof Kevin Walsh. It can go from pumping five litres per minute to 25 litres per minute. “So often, patients even with significant heart defects remain asymptomatic in terms of day-to-day activities, as they are not eating into their reserve.”
Advances in surgery, imaging and catheter interventions have led to dramatic increase in survival rates among those with complex CHD. Back in the 1940s and 1950s, 20 per cent of babies might survive their first year, but only 10 per cent would get to 18 years of age. The survival rate to at least 18 years of age is now more than 90 per cent.
Walsh is clinical lead at the adult congenital heart disease centre in the Mater Misericordiae University Hospital, Dublin, where about 10,000 adults attend for ongoing surveillance and follow-up. About 2,000 of these are complex patients, including Duff, for whom routine monitoring is an annual event, while monitoring every two or three years will suffice for others.
Most women with CHD who have had surgery or whose condition is managed medically can safely plan to have children. There are certain circumstances, however, where pregnancy is contraindicated, says Walsh.
“This would include severe pulmonary hypertension. Severe valve-narrowing or leaks would usually get fixed, and then the patient could have a successful pregnancy.”
Patients with metal valves need special precautions, because the anticoagulant medication they take can affect bone structure in the foetus.
Planning of pregnancy is recommended so medications can be reviewed and changed, or stopped. “Usually there are medications that we can switch them to ahead of time, so that the heart function isn’t affected too much in the pregnancy.”
The Mater and Rotunda hospitals collaborate on care of maternity patients with complex congenital heart disease, or other significant cardiac problems. A multidisciplinary team will discuss mode of delivery, medications required before and afterwards, and any other special precautions required.
“Occasionally,” says Walsh, “the patients come up to the Mater hospital rather than the Rotunda to have a delivery by section, and then for the mother to go to intensive care afterwards.”
Some adults with CHD will need surgical reintervention when they’re older. They may for instance require new tubes, or pacemakers or ablation procedures, although most just need clinical follow-up, maybe with medication. However, a few could possibly need a heart transplant in their 40s or 50s.
“That can be a problem because, by then, there can be effects on the liver and kidneys and other organs, making it more complicated.” The number of transplants being performed on adults with CHD in Ireland each year is small, about 10-15, he believes. It is only done as a last resort, if a suitable donor organ is available.
Another option is a ventricular assist device, which is where a pump connected to a battery is implanted in the body. “Essentially, you have to have some sort of battery power source at all times with it and then you have risks of infection and clotting while it’s in,” explains Walsh.
Mechanical valves and tissue valves have also been a big advance. A valve can be put in through a vein at the top of the leg rather than surgically, usually requiring the patient to stay just one night in hospital instead of a fortnight, and take two weeks off work instead of three months.
Due to increased medical testing being carried out in the general population, congenital heart issues may be detected in adults who do not have “proper symptoms”, he says. “There might be a bit of breathlessness or a bit of tiredness.”
Lack of scanning machines in the public health service means there can be long waiting times for MRIs. CHD patients should not have to wait more than about three months, he says, whereas, sometimes, the wait can extend to more than two years. “Some of it’s just routine follow-up, and maybe it doesn’t matter so much for [these patients], but I think it does matter for some.”
The Mater CHD centre is very understaffed when it comes to consultants, he says, and needs a “five-fold increase”. Four full-time clinical nurse specialists, one an advanced nurse practitioner, are “what keeps the service ticking over, and patients and families can contact them directly”. Each of the centre’s four consultants also work a couple of days in CHI@Crumlin, where the overall three-year survival rate of 98.6 per cent for CHD surgical procedures is among the best globally, according to figures released last June in a UK-based audit.
[ A quiet revolution in treating small children with serious heart diseaseOpens in new window ]
The vast majority of children with CHD will enjoy fulfilling lives, as Míde Duff does. She had studied for a physiology degree at University College Cork with a view to becoming a physiotherapist, but went on to do a four-year post-graduate course in medicine in Warsaw, Poland. An intern year in Glasgow led to foundation training there and she is currently working for a 12-month stretch in University Hospital Ayr on Scotland’s west coast.
Duff will be one of the speakers at The Beat Goes On conference, for people with congenital heart disease and their families, organised by the charity Heart Children in Dublin on Saturday, February 21st (registration at heartchildren.ie). She welcomes Heart Children’s development of a new, individual healthcare manual for school pupils with CHD.
“Congenital heart disease is not very well known and understood. It’s very individualistic for each patient, for each different condition,” she says.
‘There is a possibility that I may need a heart transplant. But that’s something I just put to the back of my mind, and enjoy every day when I’m healthy’
— Míde Duff, hospital doctor
Some children with CHD may tire quickly or have short-term memory issues, or difficulties with fine motor and visual motor skills. The manual will not only guide school staff but will also, she suggests, empower children and their families.
Her advice for youngsters living with CHD is to “always strive to be what you want to be in life”. Although she had to turn away from competitive athletics, she is still a keen runner and enjoys hillwalking and long-distance hikes. She also cycles and swims. “Keeping fit and being active is important for all of us, particularly for people with heart problems.”
Does she ever worry that she is pushing herself too much? “I know my limits now,” she replies. “I can’t train in the true sense of an athlete… pushing yourself beyond what you want to do. I run, I suppose, just for the joy of running.”
However, Duff knows that health challenges may lie ahead. “There is a good likelihood that I will run into trouble in the future. You know, my heart will become weaker, unfortunately.”
The small chamber is having to do all the work, which, physiologically, it was not designed to do. “So it’s enlarged and it’ll continue to enlarge. Once it’s enlarged, the pumping actually starts to fail.” The weakening will be gradual, but she is confident of the care she receives at the Mater.
“There is a possibility that I may need a heart transplant,” she adds. “But that’s something I just put to the back of my mind, and enjoy every day when I’m healthy.”
The heart is the focus of the inaugural exhibition at Humanarium, the new cafe and exhibition space at RCSI University of Medicine and Health Sciences on St Stephen’s Green in Dublin.
Visitors to Heart: More Than a Beat, which opened on February 12th, will find information on how to protect cardiac health. They can also learn how advances in medicine and health sciences research are shaping the future of heart care. The free exhibition is open to the public from 7.30am to 5pm, Monday to Friday, and Saturdays from 10am to 3pm, at 118 St Stephen’s Green, Dublin 2, D02 X0N1.
