Cardiac PCr/ATP ratios measured by 31P MRS change in cardiovascular disease giving them value as a biomarker. We scanned 13 healthy volunteers at 7T, assessing their PCr/ATP with 6 ½ min 31P CSI scans. These data have better reproducibility than a 30min 3T protocol previously published by our centre. Repeated PCr/ATP measurements from subjects in this study were not significantly (P=0.83) different. Measurements were significantly different (P<0.001) from DCM patient data acquired in a previous 7T study using the same coil and pulse sequence. This data will allow us to plan future 7T 31P-MRS clinical studies.