Determination of deoxymyoglobin changes during graded myocardial ischemia: An in vivo ¹H NMR spectroscopy study

¹H NMR spectroscopy was used to detect the proximal histidyl N(δ) proton signal of deoxymyoglobin from canine hearts in vivo during graded myocardial ischemia. The NMR signal intensity provided an indicator of intracellular oxygenation in myocardium. The relationship between the myocardial blood flow and the deoxymyoglobin concentration was successfully measured during resting, partial, and complete coronary artery occlusion conditions. The results demonstrate the feasibility to detect deoxymyoglobin using a ¹H NMR spectroscopy technique in living hearts for the first time and the possibility to use this technique for investigating myocardial oxidative metabolism nondestructively and repetitively.