title: Evaluation of respiratory chain failure in mitochondrial cardiomyopathy by assessments of 99mTc-MIBI washout and 123I-BMIPP/99mTc-MIBI mismatch.
abstract: Cardiomyopathy is one of the main features that determines prognosis in patients with mitochondrial encephalomyopathy. We investigated respiratory chain failure using 99mTc-MIBI- and 123I-BMIPP-SPECT in vivo in five patients with mitochondrial cardiomyopathty. With the lowering of cardiac function, the 99mTc-MIBI-washout rate (WOR) increased, and the 99mTc-MIBI-uptake decreased, conversely. In patients who showed severe cardiac involvement, 99mTc-MIBI-uptake was markedly reduced, and by contrast, 123I-BMIPP-uptake increased (123I-BMIPP/99mTc-MIBI mismatch). There were significant correlations between the WOR on 99mTc-MIBI-SPECT and interventricular septal thickness (IVST) on echocardiography and between WOR and left ventricular ejection fraction (LVEF) on 99mTc-MIBI-SPECT. The increased WOR and decreased uptake of 99mTc-MIBI were reflected by the lowered mitochondrial membrane potential created by mitochondrial respiratory chain whereas 123I-BMIPP/99mTc-MIBI mismatch may be created by the enhanced triglyceride-pool. These nuclear medicine techniques are the potential tools to evaluate the energy state in mitochondrial cardiomyopathy.
authors.affiliation: Second Department of Internal Medicine, Faculty of Medical Sciences, University of Fukui, 23-3 Shimoaiduki, Matsuoka, Fukui 910-1193, Japan.
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ikawa
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kawai
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Arakawa
authors.forename: Tatsuro
authors.initials: T
authors.lastname: Tsuchida
authors.forename: Isamu
authors.initials: I
authors.lastname: Miyamori
authors.forename: Masaru
authors.initials: M
authors.lastname: Kuriyama
authors.forename: Masashi
authors.initials: M
authors.lastname: Tanaka
authors.forename: Makoto
authors.initials: M
authors.lastname: Yoneda
mesh_terms: D000293:Adolescent; D000328:Adult; D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004452:Echocardiography; D004579:Electron Transport / Q000502:physiology*; D005227:Fatty Acids; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D017241:MELAS Syndrome / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D017237:Mitochondrial Encephalomyopathies / Q000000981:diagnostic imaging* / Q000503:physiopathology; D009206:Myocardium / Q000378:metabolism; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D005227:Fatty Acids; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; C049338:iodofiltic acid; D017256:Technetium Tc 99m Sestamibi