Double-nuclide study of the myocardium using 201Tl and 123I-labeled fatty acids in non-ischemic myocardial diseases.
Metabolic impairment and perfusion abnormalities are known to occur in hypertensive heart disease (HHD) and in cardiomyopathies. Free fatty acid (FFA) extraction is severely inhibited in a number of pathobiochemical reactions. This parameter was assessed using the radiolabeled FFA analogue 123I-(p-iodo-phenyl-)-pentadecanoic acid (IPPA) and 201Tl as perfusion marker, both of them injected at maximal physical workload. The regional extraction fraction of IPPA (IPPA-EF) was estimated by relating the regional IPPA and 201Tl uptake to each other. In HHD (normal coronary arteries) with posterior wall thickness less than or equal to 12 mm IPPA-EF was 77 +/- 18% (SD) in septum and 92 +/- 17% in the posterolateral wall (N = 13), with thickness of greater than 12 mm 60 +/- 23% in septum and 61 +/- 20% in the posterolateral wall (N = 8) when compared with IPPA-EF in normal subjects (= 100%, N = 9). In hypertrophic cardiomyopathy (HCM) IPPA-EF averaged 51 +/- 20% in septum and 87 +/- 10% in the posterolateral wall (N = 11). In these patient groups no systematic regional changes in 201TI uptake were observed. In dilated cardiomyopathy (DCM) both IPPA-EF and 201Tl uptake showed distinct regional variations and a great interindividual variability with a mean IPPA-EF reduction of 12% (N = 9). Thus, IPPA uptake in primarily non-ischemic myocardial disease may already be compromised when 201Tl uptake is unchanged. The double-nuclide method for IPPA-EF determination allows to eliminate the influence of flow in FFA imaging and enhances the potential of scintigraphy in the differential diagnosis of HHD versus coronary artery disease.
Knapp
W H
WH
Institute of Nuclear Medicine, Heart Center North-Rhine Westphalia, Bad Oeynhausen, FRG.
Vyska
K
K
Machulla
H J
HJ
Notohamiprodjo
G
G
Schmidt
U
U
Knust
E J
EJ
Gleichmann
U
U
D009202:Cardiomyopathies / Q000000981:diagnostic imaging* / Q000209:etiology; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D006973:Hypertension / Q000150:complications; D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D008297:Male; D008875:Middle Aged; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes
D007457:Iodine Radioisotopes; D007462:Iodobenzenes; D013794:Thallium Radioisotopes; C025391:omega-(4-iodophenyl)pentadecanoic acid