Cardiac scintigraphic findings of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes: A case report.

A 49-year-old woman was admitted to hospital because of heart failure. She was diagnosed as having mitochondrial cardiomyopathy and diabetes mellitus. Echocardiography revealed a hypertrophic and poorly contracting left ventricle. A diagnosis of mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes was established by muscle biopsy. She underwent technetium-99m-sestamibi ((99m)Tc-MIBI) and beta-methyl-p-(123)I-iodophenyl-pentadecanoic acid ((123)I-BMIPP) scintigraphic examinations. (99m)Tc-MIBI single-photon emission computed tomography revealed reduced tracer uptake in the hypertrophic left ventricular inferior wall. In contrast, there was an increase in (123)I-BMIPP uptake in the in the region of reduced (99m)Tc-MIBI uptake ((99m)Tc-MIBI/(123)I-BMIPP mismatch). There was rapid washout of (99m)Tc-MIBI from the myocardium (washout rate increased by 30%). Decreased (99m)Tc-MIBI and increased (123)I-BMIPP uptake ((99m)Tc-MIBI/(123)I-BMIPP mismatch) were the characteristics of cardiac involvement in mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes.