Q&A with Dr Louise Segan

Dr Louise Segan is a cardiac electrophysiology PhD Fellow at the Baker Heart and Diabetes Institute. Dr Segan received a Heart Foundation Health Professional Scholarship in 2020.

Atrial fibrillation is the most common rhythm problem worldwide. It is a result of abnormal electrical activity causing an irregular heartbeat. Atrial fibrillation can cause weakening of the heart muscle in some people. Although the reasons why this occurs in some and not others is not entirely clear. Scarring of the heart muscle can occur over time, which can be detected during a magnetic resonance imaging (MRI) scan of the heart. This scarring may impact the ability of the heart muscle to heal.

Dr Segan’s study aims to evaluate the impact of scarring of the heart muscle (myocardial fibrosis) on outcomes following catheter ablation for atrial fibrillation.  Scarring of the heart is often seen in people with heart failure. Her hope is that this research will lead to a better understanding of the link between atrial fibrillation and heart failure. In addition, she hopes this research will provide additional treatments strategies for people with both atrial fibrillation and heart failure.

What are you currently researching?

Atrial fibrillation is the most common type of abnormal heart rhythm (arrhythmia), which affects the ability of the heart to pump blood around the body. Over time, this can weaken the heart and can cause heart failure. In fact, atrial fibrillation affects more than 30% of people with heart failure.  There is growing awareness that people with both atrial fibrillation and heart failure benefit from treatments that return the heart rhythm to normal. A normal heart rhythm is called 'sinus rhythm'. Sinus rhythm resets the electrical activity and improves the pumping action of the heart, particularly in people with heart failure or weakening of the heart muscle.  People often feel better, experience less breathlessness, have more energy and feel less tired. The result is an improvement in quality of life). Catheter ablation is a keyhole treatment that can be used to treat abnormal heart rhythms and help restore the normal pumping action of the heart. The procedure involves inserting a thin tube (catheter) with an electrode at the tip into a blood vessel into the leg. The catheter travels up through the artery to the heart. The electrode emits radiofrequency waves (heat energy) to inactivate the part of the heart that is creating or passing the abnormal electrical impulses.

In the past, people with heart failure were far less likely to be referred for this procedure. However, in the last 10 years, increasing research recognises the benefits of this procedure for certain people with both heart failure and atrial fibrillation.  Research has also shown that the procedure is also safe.

My research involves examining the relationship between atrial fibrillation, heart failure and scarring of the heart. We know that people without scarring who have an ablation procedure experience an improvement in heart muscle function and symptoms. However, less is known about the impact of an ablation procedure in people who have scarring of the heart muscle.

Scarring can be detected with a MRI scan.  We hope to better understand the relationship between scarring and how well the heart muscle recovers in people with atrial fibrillation and heart failure who have a catheter ablation procedure. This will be compared to people who continue taking medicines for their heart conditions. This is the first study of this kind to examine this question.  Hopefully it will help us to improve outcomes for people with atrial fibrillation and heart failure and will add to existing heart failure treatment strategies.

What difference will your research make to people’s cardiovascular health in Australia?

We know that the number of people diagnosed with atrial fibrillation and heart failure is growing in Australia and abroad. We also know that cardiovascular disease remains the leading cause of the global burden of disease, causing ill-health and death. It is critical that we continue to look for ways to improve health outcomes for people living with cardiovascular disease. This includes the ability to diagnose and treat heart conditions early, which means treatments can be more effective.

We know that atrial fibrillation tends to get worse over time. Research shows that the longer a person has atrial fibrillation, the more likely they are to have persistent symptoms, despite treatments like catheter ablation. Overwhelming research supports early intervention and treatment of atrial fibrillation to restore the heart rhythm to normal ‘sinus rhythm’. However, even if a person has had atrial fibrillation for a long time, they may still benefit from an ablation procedure.

We hope to show the benefit of catheter ablation in people with heart failure and atrial fibrillation.   In turn, this will hopefully encourage doctors to consider referring people with atrial fibrillation for treatment earlier. We also hope to bridge the gap between cardiologists with expertise in atrial fibrillation and heart failure. By combining their knowledge, we can improve outcomes for people living with both heart failure and atrial fibrillation.

What motivated you to do your research?

I have been involved in heart research for many years and across many areas. I have developed a strong research interest in better understanding the relationship between electrophysiology (electrical activity of the heart) and heart disease. I feel there is a real need to establish a holistic model of care for these patients, given the significant overlap in these conditions. Through my research, I hope to better understand the link between atrial fibrillation and heart failure so that we can improve care for the growing number of people affected by these conditions. My focus is on early treatment and prevention, providing the best possible care. I am passionate about advocacy and empowering people through heart health education. This helps people to understand their options, make informed decisions and feel in control of their health journey. Understanding their heart conditions means they can have more input into the care they receive.

What role has Heart Foundation funding had in your career journey?

I am extremely humbled to receive a Heart Foundation postgraduate research scholarship. This funding will allow me to dedicate my time to this clinical trial and other related projects. This scholarship will provide a fantastic foundation for me to continue to build a career in heart research. I will also be able to collaborate with and learn from other researchers who have navigated this journey. I truly appreciate the support of the Heart Foundation and I am so thankful that the Heart Foundation recognises the importance of this research.  I believe that together we can make a huge difference to people’s lives and improve the future of heart health in Australia.

Do you have a message for Heart Foundation supporters?

Thank you for your generous support of the Heart Foundation. It is with the support of our community that these advances in research are transformed from ideas into reality. I have long admired the work of the Heart Foundation. My research would not be possible without the generous support of Heart Foundation donors and supporters. As a health professional, it is inspiring to be able to work together to improve awareness and promote heart health for all Australians.