Abstract
To assess the usefulness of in vivo 31P nuclear magnetic resonance (NMR) spectroscopy, we investigated spectra from the myocardium in 6 patients with old Q-wave infarction (QMI), 6 with old non-Q-wave infarction (NQMI) and 9 con-trols by ECG-gated depth-resolved surface-coil spectroscopy. External hex-amethylphosphoric triamide (HMPT) was used to quantify the signal intensities. Left ventricular weight in the region of interest (LVW) was estimated from IH magnetic resonance images. The extent score by 201T1 scintigraphy was deter-mined in 3 QMI and 4 NQMI patients. No significant differences were found among the 3 groups in peak area ratios of 31P NMR spectra to phosphocreatine (PCr) or adenosine triphosphate (ATP). Compared with controls, significant reductions were observed in values for the peak areas of PCr normalized by the standard HMPT (PCr/HMPT) or by both HMPT and LVW (PCr/HMPT/LVW) for QMI patients (p<0.05), and in ATP/HMPT and ATP/HMPT/LVW for QMI and NQMI patients (p<0.01). There was a significant negative correla-tion between ATP/HMPT and the 201T1 scintigraphy extent score (p<0.05). These findings suggest that in vivo 31P NMR spectroscopy can detect high-energy phosphate reduction in the infarcted myocardium and may be useful in evaluating myocardial viability.
