[Correlation of regional wall motion and fatty acid metabolism in coronary artery disease, hypertension, and hypertrophic cardiomyopathy: assessment by dual-isotope SPECT with thallium-201 and iodine-123 beta-methyl fatty acid analogue]

Abstract

In order to investigate the correlation between cardiac fatty acid metabolism and regional wall motion, dual-isotope tomography using thallium-201 and iodine-123 labeled 15-(p-iodophenyl)-3-R, S-methylpentadecanoic acid (BMIPP), was performed in 15 patients with coronary artery disease (CAD), hypertension, or hypertrophic cardiomyopathy (HCM). The uptake of thallium and BMIPP was scored and compared with left ventricular regional wall motion assessed by 2-dimensional echocardiography and radionuclide ventriculography. The incidence of a complete agreement of thallium and BMIPP scores was significantly higher in hypertension (64%) and CAD (63%) groups compared to HCM patients (24%), while a lower BMIPP uptake compared to that of thallium (mismatching) was observed more frequently in HCM (65%) than in hypertension (31%) or CAD (33%). Only 3 infarct patients had regional wall motion abnormality which was detected in 20 (95%) of 21 segments with a low BMIPP uptake. Furthermore, compared to thallium perfusion, decreased BMIPP uptake much more corresponded to reduced wall motion in 8 of 11 segments with mismatching. Thus, metabolic abnormality assessed by BMIPP is well associated with asynergy in CAD patients, whereas the discrepancy of fatty acid metabolism and contraction is more dominant in HCM, suggesting that the combined assessment of thallium perfusion, BMIPP uptake, and regional wall motion might contribute to better understanding the pathogenesis of various cardiac disorders.