Detection of low phosphocreatine to ATP ratio in failing hypertrophied human myocardium by 31P magnetic resonance spectroscopy.

Phosphorus-31 magnetic resonance spectroscopy can be used to study intracellular biochemistry non-invasively by measuring the relative proportions of high energy phosphates. Study of deteriorating cardiac metabolism might be useful in the management of hypertrophy and heart failure. 31P magnetic resonance spectroscopy was carried out in fourteen patients with aortic valve disease (six with aortic stenosis, eight with aortic incompetence). Six patients were receiving treatment for symptoms of heart failure. The phosphocreatine (PCr) to ATP ratio in these patients (1.1 [SD 0.32]) was significantly lower than that in thirteen controls (1.5 [0.2], p less than 0.001) or in the eight patients who did not have symptoms of heart failure (1.56 [0.15], p less than 0.0035). These findings indicate that heart failure in aortic valve disease is associated with low PCr, which could be due to loss of intracellular creatine. The measurement could eventually have a role in helping to determine the optimum timing for aortic valve replacement.