The Brain-Heart Connection
Updated: Apr 6
They are dubbed “little brains” – brain cells on the heart’s surface – and understanding how they work may lead to reducing a prevalence of stroke and dementia.
That is the hope of Associate Professor Johanna Montgomery, who leads a first-class research team in Auckland that is looking at Atrial Fibrillation (AF) – the most common serious cardiac arrhythmia.
AF results in the heart beating too rapidly, slowly, or erratically, impairing heart function. Twelve per cent of people aged 75 or older suffer from it, but it affects younger people too, resulting in significant clinical consequences including a five-fold increase in stroke, a three-fold increase in heart failure, and a two-fold risk of dementia.
“We are looking at the nuts and bolts of how these brain cells – neurons – work,” Johanna says. “They are the last part of the pathway from your brain to your heart, with somewhere between 14,000 and 40,000 neurons on the surface of the heart. We think these brain cells can induce arrhythmia, and in turn be the key to preventing it.
“Having the arrhythmia itself can significantly impact your quality of life,” Johanna says. “The treatment strategies are either using drugs – many of which can have side effects, including causing other arrhythmia. Or you can have a surgical procedure – but unfortunately people often need multiple surgeries and it doesn’t always work.
Heart health video: medical research finds atrial fibrillation and arrhythmia linked to stroke, dementia, heart failure
Historically, AF research has been focused on heart cells. With the support of funding from the Auckland Medical Research Foundation, Johanna is using her expertise in brain physiology and applying it to the heart.
Johanna’s project is cutting edge, as the team is recording the electrophysiology of human cells using samples from patients collected during open heart surgery. The project brings together the collective expertise of a neurophysiologist, cardiac physiologists, heart surgeons and cardiologists, all focussed on AF treatment.
“That is something that is really neat about New Zealand is that we can have those direct links and work together on this kind of research – the research benefits immensely from the clinical input.
“Our big picture hope is the research that we do will significantly contribute to a treatment or cure for AF.”
The Auckland Medical Research Foundation (AMRF) has been funding Johanna since she started her lab at the University of Auckland School of Medical Sciences in 2005. AMRF Executive Director Sue Brewster says it is vital that work like Johanna’s is supported on an ongoing basis.
“Our generous donors have enabled Johanna to lead this ground-breaking, collaborative research that has the potential to impact the lives of so many – and enabled research of a kind that has never been published before.”
Johanna is asked to present her work to researchers around the globe and is proud of the reputation New Zealand has on the world stage.
“Having clinicians and scientists work together is a powerful combination and being the size of New Zealand, means we can collaborate whereas it is not really easy in many parts of the world.
“The impact of suffering from AF can be debilitating. The only way we are going to be able to prevent, treat or cure AF is via research to understand what is causing it in the first place.”
“Having the arrhythmia itself can significantly impact your quality of life. New knowledge, tools, and strategies are critical for developing effective therapies.”