Untersuchungen des kardialen energiestoffwechsels bei herzvitien mit der ³¹P-MR-spektroskopie

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.