MYOCARDIAL SCINTIGRAPHIC STUDY WITH I-123 15-(P-IODOPHENYL)-3(R,S)-METHYLPENTADECANOIC ACID IN PATIENTS WITH HYPERTROPHIC CARDIOMYOPATHY

I-123 15-(p-iodophenyl)-3(R,S)-methylpentadecanoic acid (BMIPP) myocar dial scintigraphy and exercise stress thallium (T1)-201 myocardial sci ntigraphy were performed in 17 patients with hypertrophic cardiomyopat hy (HCM) to evaluate the existence of abnormal fatty acid metabolism i n the myocardium and the relationship between this abnormality and myo cardial ischemia. On the BMIPP scintigraphy, abnormalities were found in 12 of 17 patients (71%). Five patients showing no abnormalities on the BMIPP scintigraphy had well preserved exercise tolerance and had l onger exercise duration than the others showing BMIPP scintigraphic ab normalities (P < 0.001). On the evaluation of the segmental abnormalit ies, T1 scintigraphic abnormalities were found in 15 (50%) of 30 segme nts showing decreased accumulation of BMIPP. On the other hand, BMIPP scintigraphic abnormalities were found in all segments showing decreas ed accumulation of T1. The sites of decreased accumulation of BMIPP an d T1 were in good agreement with the sites of wall hypertrophy. Four p atients showing BMIPP scintigraphic abnormalities and no T1 scintigrap hic abnormalities were in higher New York Heart Association functional classes, had shorter exercise duration (P < 0.05) than the 5 patients showing no abnormalities on either scintigraphy. It is concluded that abnormalities of fatty acid metabolism in the heart are detected at a high rate in patients with HCM, and may be due in part to factors oth er than myocardial perfusion disturbance.