Auckland leads major international collaboration into heart disease

02 August 2013

The causes of abnormal heart rhythms will come under scrutiny by scientists in a major new investigation led by researchers from the University of Auckland.

The study, due to begin in October, will map the determinants of arrhythmia (abnormal electrical rhythm) in structural heart disease.  The five year $5 million research programme is funded by a recent grant from the Health Research Council of New Zealand.

This work, which will be directed by Professors Bruce Smaill and Peter Hunter, involves a high level of local and international collaboration.  It will include senior investigators from the Auckland Bioengineering Institute and the Faculty of Medical and Health Sciences at the University of Auckland, Auckland City Hospital, and the universities of Oxford, Michigan and Gent.  Leading researchers from other universities in Europe, the United Kingdom and Canada will also take part.

Hearts with fibrosis (excessive connective tissue between heart muscle cells) are susceptible to arrhythmia and fibrillation. Ventricular fibrillation - complete loss of coordinated activity in the lower chambers of the heart - is fatal if not reversed.

Atrial fibrillation, which affects the upper chambers of the heart, is not immediately life-threatening. However, this relatively common condition increases the risk of stroke and can be debilitating.

The mechanisms linking cardiac fibrosis with arrhythmia and fibrillation remain unclear, and will be investigated during the study.  This will be done by combining recordings of 3D electrical activity in the heart with detailed structural imaging and computer modelling - an approach pioneered by the Auckland research group.

“Increased understanding of the links between fibrosis and arrhythmia will provide new targets for assessing the risk of sudden death due to ventricular fibrillation,” says Professor Bruce Smaill from the Auckland Bioengineering Institute.  "Improved knowledge of the mechanisms that trigger and sustain arrhythmia are also an important step toward developing better ways of countering long-standing atrial fibillation, an area where current treatment outcomes are disappointing," he says.

The research programme will also focus on novel methods for mapping electrical activation in the atrial chambers during atrial fibrillation and of identifying regions of the atria that drive electrical instability from these maps.

“If validated, the non-contact electrical mapping techniques proposed here could have real impact on clinical intervention,” says Dr Nigel Lever, a senior cardiologist at Greenlane Cardiovascular Services, Auckland City Hospital and a member of the research team.

A further objective of the programme is to establish cardiac electrophysiology data standards that will enable analysis tools developed in the wider scientific community to be used more readily in a clinical setting.

“Such an open-source approach facilitates data sharing by researchers, but also has the potential to increase the efficiency of clinical workflow and enhance clinical decision making,” says Professor Peter Hunter, Director of the Auckland Bioengineering Institute.

This study will generate the first comprehensive 3D maps of tissue structure in hearts with atrial fibrillation and heart failure. Computer models that incorporate this structure will be combined with measured electrical activation maps from the same hearts to provide new understanding of the increased susceptibility to arrhythmia of individuals with structural heart disease.

Finally, novel electrical mapping techniques and data analysis methods will be developed and this could contribute to improved health delivery outcomes in patients with chronic cardiac arrhythmia.

For more information contact:

Suzi Phillips

Faculty of Medical and Health Sciences, Communications The University of Auckland Email s.phillips@auckland.ac.nz