Marie Allen Schroeder1, Helen J. Atherton1, Lisa C. Heather1, Mark Aaron Cole1, Kieran Clarke1, George K. Radda1, Damian J. Tyler1
1Physiology, University of Oxford, Oxford, Oxfordshire, UK
As decreased pH is characteristic of myocardial ischaemia, the ability to dynamically monitor cardiac pH may be clinically important. This study assessed the validity of using hyperpolarized [1-13C]pyruvate, specifically the H13CO3-/13CO2 ratio, as a marker of intracellular pH in the isolated perfused heart. Intracellular 13C pH measurements made in healthy hearts, with 1 s temporal resolution, were validated using steady-state 31P MR spectroscopy (MRS). Additionally, pH equilibration showed distinct kinetic trends in healthy and post-ischaemic hearts. These results have indicated that H13CO3-/13CO2 could be a useful parameter to monitor alterations to cardiac metabolism that occur due to ischaemic heart disease.