Auckland Bioengineering Institute
Cardiac Metabolism
The electrical and mechanical performance of the heart is fundamentally dependent upon its metabolism. In fact reduced blood supply to the heart (ischaemia), compromising its metabolism, is the main cause of mortality in the developed world.
This altered metabolism produces many changes to the mechanical and electrical properties of heart cells. Despite extensive experimental studies, however, the complicated sequence of events leading from the initial trigger, the blockage of a coronary artery, to life-threatening pump failure remains poorly understood.
We utilise both theoretical and experimental techniques to study this complex cardiac function. We have developed a unique microcalorimeter to simultaneously measure heat production and mechanical performance (force and shortening) of isolated cardiac trabeculae. We combine this experimental approach with the development of biophysically-based mathematical models of cardiac metabolism with the particular aim of characterising metabolic compromise during ischaemic events.
Heat output (upper, red trace) and force production (lower, blue trace) of a trabecula during a Ba2+-contracture.
Simulated responses (pHi, [Na+]i, [Ca2+]i and force) to respiratory acidosis, induced by reversibly increasing extracellular CO2 from 1.2 to 10 mM (indicated by the bar).
The regional work calculated through the heart contraction cycle, the small cubes located at the Gaussian quadrature points in the deforming finite element mesh are coloured according to the work from blue (low) to red (high).
The Cardiac Metabolism Project gratefully acknowledges the support of its funding partners:
