Evaluation of myocardial viability following ischemic and reperfusion injury using phosphorus 31 nuclear magnetic resonance spectroscopy in vivo

Abstract

Recovery of myocardial high-energy phosphate (HEP) metabolism after coronary occlusion and reperfusion may vary with ischemic duration and may provide information about the extent of tissue viability. To evaluate the differences between varying durations of ischemia and to attempt to identify metabolic indexes of salvaged viable tissue, intact New Zealand white rabbits underwent either 30 (group 1; n = 8) or 60 (group 2; n = 8) minutes of coronary occlusion followed by reperfusion. HEP metabolism was evaluated with cardiac gated phosphorus 31 (31P) nuclear magnetic resonance (NMR) spectroscopy with a 2.0 T spectrometer. While similar HEP changes were observed during ischemia in both groups, differences in HEP recovery between groups were seen following reperfusion. Group 1 animals demonstrated a gradual decrease in inorganic phosphates (PI) (p p = ns versus baseline), and a gradual increase of adenosine triphosphate (ATP) to pre-ischemic levels. Group 2 animals had elevated levels of Pi (p p p p p r = 0.59, p R = 0.73, p 31P NMR spectroscopy may be useful in the evaluation of postischemic myocardial viability.