[The characteristic feature of myocardial imaging with 123I-labeled 15-(p-iodophenyl)-3R,S-methylpentadecanoic acid in hypertrophic cardiomyopathy with asymmetric septal hypertrophy].

The aim of this study was to elucidate the characteristic feature of myocardial imaging with 123I-labeled 15-(p-iodophenyl)-3R,S-methylpentadecanoic acid (BMIPP) in the patients with hypertrophic cardiomyopathy (HCM). In 26 patients with asymmetric septal hypertrophy (ASH), the imaging data were acquired for 15 minutes after the injection of 123I-BMIPP by the emission computed tomography (ECT). ECT image was divided into 17 segments to score the severity of the defect in each segment using a 5-point grading system from score 3 to score -1; score 3 = severely decreased tracer uptake, score 2 = moderately decreased tracer uptake, score 1 = mildly decreased tracer uptake, score 0 = normal and score -1 = increased tracer uptake. Reduced uptake (Defect Score > or = 2) was frequently observed in septal portion of anterior wall (65%), septal portion of posterior wall (62%) and apical wall (73%). Defect score was higher in septal portion of anterior wall (p < 0.001), septal portion of posterior wall (p < 0.01) and apical wall (p < 0.01) than in the ventricular septum. This result indicates that in hearts with ASH, 123I-BMIPP image reveals severely impaired fatty acid metabolism in these regions. With the reference of the previous report about histologic features in necropsy hearts with HCM, myocardial fatty acid metabolic disorder shown by reduced 123I-BMIPP uptake is closely related to the histological abnormalities in hearts with HCM.