Impaired myocardial accumulation of 15-(p-iodophenyl)-9-(R,S)-methylpentadecanoic acid in a patient with hypertrophic cardiomyopathy and exercise-induced ischemia due to vasospasm

We encountered a patient with hypertrophic cardiomyopathy complicated with exercise-induced myocardial ischemia. Exercise-stress Tc-99m-tetrofosmin im aging demonstrated reversible ischemia in the lateral wall, whereas resting fatty acid imaging with a new beta-methyl branched fatty acid analogue, I- 123-15-(p-iodophenyl)-9-(R,S)-methylpentadecanoic acid (I-123-9-MPA), showe d impaired uptake and accelerated washout kinetics in the inferoapical and posteroseptal walls but not in the ischemia-related region. These findings suggest that the metabolic derangement is closely related to cardiomyopathy per se rather than exercise-induced myocardial ischemia in this patient wi th hypertrophic cardiomyopathy and a spastic coronary lesion so that myocar dial perfusion and I-123-9-MPA imagings may contribute to clarifying the et iological background of impaired myocardial fatty acid metabolism.