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PURPOSE: Heart valve disease combined with left ventricular hypertrophy leads to derangements in cardiac energy metabolism, which can be detected non-invasively by 31P-MR-spectroscopy. The purpose of the present study was to examine whether the derangements in cardiac metabolism are reversible after surgical valve replacement. PATIENTS AND METHODS: 10 healthy volunteers and 10 patients with aortic stenosis (pressure gradients > 60 mmHg) were included. For assessment of energy metabolism, 31P-MR spectra were obtained with a double oblique 3D-CSI technique (voxel size 25 cm3). In 5 of 10 patients, follow-up examination was performed 3 months after surgical valve replacement (SVR). Left ventricular (LV) function was analyzed by cine MRI. RESULTS: Before SVR the myocardial phosphocreatine to adenosinetriphosphate (PCr-ATP) ratio was significantly (p = 0.0002) reduced to 0.80 +/- 0.25 in patients compared to 1.65 +/- 0.21 in volunteers. 3 months after SVR, LV mass had significantly (p = 0.04) decreased from 238 +/- 33 g to 206 +/- 47 g. At the same time a significant (p = 0.04) increase of the PCr-ATP ratio from 0.80 +/- 0.25 to 1.28 +/- 0.22 was observed. A slight, but not significant, reduction of the phosphodiester ATP ratio was observed before SVR, with a trend towards normalization after SVR. CONCLUSIONS: After SVR, the deranged energy metabolism shows a trend towards normalization. Further follow-up is necessary to determine whether complete normalization of the energetic derangement can be observed over longer periods of time following SVR.

Purpose: A quantitative 31P-MR-spectroscopic technique was used to assess the energy metabolism in healthy and diseased myocardium. Methods: 31P-spectra were acquired on a 1.5 T scanner using a 3D-chemical shift imaging technique. Based on the anatomical information provided by 1H- images, SLOOP (Spatial Localization with Optimal Pointspread Function) allows to obtain spectra from defined compartments. With SLOOP a free voxel shape with adaption to anatomic structures, e.g. the myocardium, is possible. Absolute values for phosphocreatine (PCr) and adenosine triphosphate (ATP) were determined using an external standard. Results: 31P-spectra showed only minimal contamination by surrounding tissue. The standard deviation for the determined values of healthy volunteers was low. Compared to healthy volunteers, reduced PCr and ATP concentrations were seen for dilative cardiomyopathies and coronary artery disease and unchanged concentrations were observed for hypertensive heart disease. Conclusion: 31P-MR- spectroscopy with SLOOP allows a non-invasive, quantitative analysis of cardiac energy metabolism.