From Data to Diagnosis: Imperial Research for World Heart Day

Your heart will beat about two billion times in a lifetime, slowing to around 60 beats per minute during sleep and accelerating to more than 200 during intense exercise. This remarkable adaptability is driven by the heart’s electrical wiring system – the cardiac conduction system – which initiates and coordinates every beat.

Dr Alicia D’Souza is an Associate Professor in Cardiac Electrophysiology, and her lab is one of the few worldwide dedicated to understanding how it functions and why it fails. When it malfunctions, the consequences are serious: fainting, exercise intolerance, heart failure, atrial fibrillation, or even sudden death. Currently, treatment relies almost entirely on pacemakers and other surgically implanted devices – effective but invasive, costly, and not suitable for all patients.

To uncover the root causes, Dr D’Souza’s team combine living human heart tissue, advanced electrophysiology, multi-omics profiling, gene therapy tools, precision transgenic mouse models, and computer modelling. “This integrated approach allows us to probe how inflammation, ageing, circadian rhythms, heart failure, and exercise training remodel the conduction system and trigger arrhythmias.”

Conduction system disease is treated entirely with pacemakers, cardiac resynchronisation therapy, or conduction system pacing. These save lives but do not cure the underlying biology, don't work for all patients, and are expensive from a public health perspective. Dr D'Souza's lab works to address these issues by:

•                Identifying biomarkers and mechanisms – from cytokines, circadian clock genes, and microRNAs to ion channel remodelling – that predict or drive disease.

•                Developing drug- and gene-based therapies (e.g., Galectin-3 inhibition, anti-cytokine treatment, microRNA modulation) to maintain healthy rhythm and reduce reliance on devices.

“This could directly benefit patients by offering less invasive, biologically targeted treatments, lowering risks and costs, and improving quality of life. At the same time, our human tissue studies provide mechanistic insights of immediate relevance to clinicians, regulators, and industry developing next-generation rhythm therapies.”

In the past few years, Dr D’Souza’s team have uncovered several paradigm-shifting insights into how the heart’s wiring system ages, adapts, and fails.

They also overturned a century-old dogma by showing that the sinoatrial node contains its own molecular clock, independent of the nervous system. This intrinsic circadian machinery, together with newly identified cortisol-sensitive pathways, helps to explain the morning peak in lethal arrhythmias.

In the context of arrhythmias in endurance athletes, “we demonstrated that the slow heart rates and conduction changes long observed in endurance training are not simply due to heightened vagal tone, as assumed for decades, but arise from intrinsic remodelling of pacemaker cells themselves. Extending this work, we recently mapped pulmonary vein sleeve myocytes as novel atrial fibrillation triggers in athletes, a discovery that was recognised with a Young Investigator Award for Arrhythmia and Electrophysiology at the European Society of Cardiology for Dr Roman Tikhomirov.”

Taken together, these findings overturn the view that conduction system decline is an inevitable by-product of ageing, disease, or training. Instead, they reveal it as a mechanistically driven process, one that can be intercepted, corrected, and ultimately prevented.

Dr D’Souza’s goal is “to transform conduction disease from a surgically managed condition to one that is preventable and druggable. This vision includes reducing pacemaker implants, particularly in frail elderly patients; developing new therapies for His–Purkinje dysfunction in heart failure where devices fall short; delaying or preventing atrial fibrillation that often follows conduction system dysfunction; and advancing precision medicine through biomarker-guided, computationally modelled interventions delivered to the right patient at the right time.”

She’s working toward a future where rhythm disorders are not just managed with devices, but prevented and treated at their source. “Your heartbeat depends on a wonderfully intricate yet fragile wiring system that can be disrupted by ageing, inflammation, stress, and lifestyle choices. Protecting it starts with prevention: regular physical activity, balanced nutrition, and avoiding cardiovascular risk factors all reduce strain on the heart. But the future holds even more promise. Our research is opening the door to new medicines and targeted therapies that can restore the heart’s natural rhythm, reducing reliance on devices and giving patients healthier, longer lives.”

For Dr Paz Tayal, Associate Professor in Cardiology at Imperial’s National Heart and Lung Institute, this stark reality drives her mission. A consultant cardiologist specialising in heart muscle diseases, Dr Tayal has spent over a decade researching cardiomyopathies, particularly genetic forms, to uncover how sex and genetics shape disease outcomes. 

Her work is rooted in a simple but powerful observation: “We accept that men and women have different shoe sizes, but when it comes to healthcare, everything is treated as sex-neutral.” That disconnect sparked her research into whether biological sex should influence how we diagnose and treat heart muscle conditions. “It doesn’t matter if the answer is yes or no, what matters is that we’ve done the research to find out.” 

Dr Tayal’s studies have revealed striking sex differences in Dilated Cardiomyopathy (DCM). Her team showed that current diagnostic thresholds disproportionately identify men, while sex-specific approaches, such as imaging-first and genotype-first strategies, help uncover cases in women that would otherwise be missed. “If you’re missing diagnoses, you’re missing treatment – and that’s what helps people long term.” 

Her recent research also found that variants in the desmoplakin (DSP) gene are three times more likely to affect women, potentially putting them at greater risk of dangerous heart rhythms. These discoveries are helping to reshape how clinicians think about heart disease in women and underscore the need for tailored diagnostics and long-term monitoring, especially after pregnancy. 

Dr Tayal is also a passionate advocate for women’s cardiovascular health. She co-leads the Imperial Women’s Cardiovascular Health Network of Excellence, which brings together clinicians, scientists, and patient advocates to raise awareness of sex differences in health and disease and improve access to care for women, and the BHF–NIHR PREG-Heart study, which explores how pregnancy affects long-term heart health. She’s deeply committed to involving patients in research, ensuring that lived experiences guide scientific priorities. 

But she’s also candid about the challenges. “One of the most pressing challenges is the declining number of clinical academics in the UK. Without a strong pipeline of clinicians engaged in research, there is a real risk that progress in translating scientific discoveries into patient benefit will stall.” 

Dr Tayal’s message for World Heart Day is clear and urgent:

She believes that young women need to be better informed. “We all know to check our breasts and attend cervical screenings, but heart health isn’t on the radar, and it should be.” 

Her work is contributing to a future where every patient with cardiomyopathy receives the right care at the right time. “By closing the gaps in diagnosis and treatment, we can improve survival and quality of life for all.”