Nuclear magnetic resonance spectroscopy: its present and future application to studies of myocardial metabolism

The current status of NMR spectroscopy as a quantitative analytic method for studying a variety of aspects of cardiac metabolism and physiology is reviewed. It should be apparent that this method has much to offer as an experimental tool. 31P-NMR provides a valuable on-line method for continuous measurement of tissue pH and high energy phosphate content which will be invaluable in studies probing the relationship between myocardial function and tissue metabolism. 13C-NMR has only begun to be applied to the study of myocardial biochemistry, but promises to provide truly unique information on the in vivo control of the reaction pathways involved in the synthesis and breakdown of tissue glycogen. Finally, in vivo proton spectroscopy of the heart, while still in the very early phases of its development, holds forth perhaps the greatest promise to serve both as a valuable analytic method to the biochemist and perhaps eventually as a diagnostic method to the clinician. However a number of experimental obstacles remain to be overcome before NMR spectroscopy could become a useful tool to clinical cardiology. Foremost among these will be resolving issues of localization of the source of spectral information. In addition the issues of machine expense and patient safety will be continuing sources of concern and debate. (Auth.)