Proton NMR spectroscopy in canine myocardial infarction

Proton NMR spectroscopy was used to study the relationship between proton relaxation times and other resonances in the proton spectra, such as lipids, creatine, and choline/carnitine in subacute (8-day-old) myocardial infarctions. Eight mongrel dogs received operative ligation of the left anterior descending coronary artery (four were permanently occluded, four were occluded for 1 h and reperfused) and were sacrificed 8 days later so that tissue samples could be prepared for NMR spectroscopy. The results of this study indicate that (for the core of infarcted tissue) the lipids do not contribute directly to the increased bulk relaxation times associated with myocardial infarction and that the lipid peaks (2.3, 1.2, 0.8 ppm) and creatine peak (3.0 ppm) are more specific to the kind of infarct than to the relaxation times. Therefore, analysis of the proton spectrum of myocardial tissue may serve as a method for tissue characterization.