The myocardial phosphocreatine-to-ATP ratio, measured noninvasively with 31P-MR spectroscopy, is a predictor of both total and cardiovascular mortality in patients with dilated cardiomyopathy.

We examined possible age- and gender-specific differences in the function and mass of left (LV) and right (RV) ventricles in 36 healthy volunteers using cine gradient-recalled echo magnetic resonance imaging. Subjects were divided into four groups (nine men and nine women in each): men aged under 45 years (32 +/- 7), women aged under 45 (27 +/- 6), men aged over 45 (59 +/- 8), and women aged over 45 (57 +/- 9). Functional analysis of cardiac volume and mass and of LV wall motion was performed by manual segmentation of the endocardial and epicardial borders of the end-diastolic and end-systolic frame; both absolute and normalized (per square meter body surface area) values were evaluated. With age there was a significant decrease in both absolute and normalized LV and RV chamber volumes (EDV, ESV), while LV and RV masses remained unchanged. Gender-specific differences were found in cardiac mass and volume (for men and women, respectively: LV mass, 155 +/- 18 and 110 +/- 16 g; LV EDV, 118 +/- 27 and 96 +/- 21 ml; LV ESV, 40 +/- 13 and 29 +/- 9 ml; RV mass, 52 +/- 10 and 39 +/- 5 g; RV EDV, 131 +/- 28 and 100 +/- 23 ml; RV ESV, 53 +/- 17 and 33 +/- 15 ml). Normalization to body surface area eliminated differences in LV volumes but not those in LV mass, RV mass, or RV function. Functional parameters such as cardiac output and LV ejection fraction showed nonsignificant or only slight differences and were thus largely independent of age and gender. Intra- and interobserver variability ranged between 1.4% and 5.9% for all parameters. Cine magnetic resonance imaging thus shows age- and gender-specific differences in cardiac function, and therefore the evaluation of cardiac function in patients should consider age- and gender-matched normative values.

Surgical valve replacement for aortic stenosis leads to normalization of the left ventricular torsion 1 year after surgery. Pressure overload before surgery is associated with an increase of systolic left ventricular wringing motion, possibly serving as a compensatory mechanism. This mechanism declines with increasing left ventricular hypertrophy and dilatation.

Evidence of delayed hyperenhancement of dysfunctional myocardium may be used to predict lack of mechanical improvement or nonviability, whereas the lack of hyperenhancement can be correlated with improvement of regional contractility or viability after revascularization.

In the present work, we studied clinical and haemodynamic correlates of impaired cardiac high-energy phosphate metabolism in patients with heart failure due to dilated cardiomyopathy (DCM). Myocardial 31P-magnetic resonance (MR) spectra were obtained at 1.5 T in 14 volunteers and 23 patients with DCM (mean ejection fraction 34%) in order to quantify the creatine phosphate (CP)/ATP ratio. In addition, patients underwent cardiac catheterization and echocardiography. Compared to volunteers (2.02 +/- 0.11), CP/ATP ratios were significantly reduced in DCM patients (1.54 +/- 0.10; P < 0.05), indicating impaired high-energy phosphate metabolism. CP/ATP ratios correlated with the clinical severity of heart failure estimated from the NYHA class (r = 0.47, P < 0.01); also, CP/ATP correlated with left ventricular ejection fraction (r = 0.54, P < 0.01) and left ventricular end-diastolic wall thickness (r = 0.51, P < 0.01). Thus, 31P-MR spectroscopy can detect abnormal cardiac high-energy phosphate metabolism in patients with heart failure due to DCM. These abnormalities correlate with clinical and haemodynamic parameters. Future studies will have to determine whether 31P-MR spectroscopy can contribute to the routine clinical evaluation of patients with heart failure.

DWI facilitates fast, accurate and comprehensive workup in Crohn disease without the need for intravenous administration of contrast medium. Contrast-enhanced MRI is superior in terms of spatial resolution and multiplanar acquisition.

Human cardiac 31 P nuclear magnetic resonance (NMR) spectra are usually quantified in relative terms, i.e., the ratio of metabolite signals is calculated. If 31 P NMR spectroscopy of the heart is to emerge as a clinically relevant diagnostic modality, reliable quantification of absolute concentrations of 31 P metabolites is required. We applied spectral localization with optimal point spread function (SLOOP) 31 P NMR spectroscopy to measure absolute concentrations of phosphocreatine (PCr) and adenosine triphosphate (ATP) in human myocardium. The accuracy of the quantification was first validated in a phantom study. Seven healthy volunteers (aged 19-29 years) were then examined at 1.5 T using a nominal spatial resolution of 25 mL. SLOOP allowed us to obtain localized spectra from compartments anatomically matched to the left ventricular wall. The a priori knowledge of the anatomical structure was obtained from 1 H images. The spatially varying effects of saturation, off-resonance, and sensitivity were considered during the reconstruction process. Metabolites were quantified with reference to an external 31 P standard. Concentrations of 9.0 ؎ 1.2 and 5.3 ؎ 1.2 mmol/kg wet wt (mean ؎ SD, n ‫؍‬ 9) were determined for PCr and ATP in normal heart, respectively. The influence of nuclear Overhauser enhancement on metabolite quantification is dis-

The stereoselective total synthesis of the sesquiterpene herbertenediol (3) and of its naturally occurring dimers, mastigophorenes A [(P)-1] and B [(M)-1], is described. Following the “lactone concept”, the configuration at the biaryl axis was atropo-divergently induced to be P or, optionally, M, by stereocontrolled reductive ring cleavage (diastereomeric ratio up to 97:3) of the configurationally unstable joint biaryl lactone precursor 17 using the oxazaborolidine−borane system, through dynamic kinetic resolution. Mechanistic considerations of the lactone coupling suggested interference by a methoxy group next to the halogen substituent and led to an improvement of the coupling yield from 39 to 87% (to give the lactone 37). As a new, likewise highly efficient variant of the lactone method, we report for the first time thenow nondynamickinetic resolution of a structurally related, but centrochiral “aliphatic−aromatic” lactone, (rac)-10. Its highly efficient (k rel > 300) enantiomer-differentiating Corey−Bakshi−Shibata reduction delivers the centrochiral building block (R,R)-10 in good chemical yield and with excellent stereochemical purity (enantiomeric excess > 99.9%; enrichment of the starting matrial). The new synthesis of natural herbertenediol (3) confirms its absolute stereostructure as well as that of its dimers, (P)-1 and (M)-1.