Myocardial metabolic changes in hypertrophic cardiomyopathy.
We evaluated myocardial blood flow, glucose and oxygen metabolism using PET in hypertrophic cardiomyopathy (HCM).


METHODS
PET studies using 18F-fluorodeoxyglucose (FDG) and 11C-acetate were performed at rest in patients with HCM and normal subjects as a control group. The metabolic rate of glucose (MRGlu), K mono value as a marker of oxidative metabolism, and myocardial blood flow were estimated from serial dynamic FDG and 11C-acetate PET studies.


RESULTS
Myocardial blood flow (%) did not differ significantly in hypertrophic and nonhypertrophic myocardium (90.3 +/- 3.1 versus 91.7 +/- 3.4). The MRGlu in hypertrophic myocardium, however, was lower than that of hypertrophic and normal myocardium (0.44 +/- 0.10 versus 0.52 +/- 0.15 and 0.53 +/- 0.15 mumole/min/g, respectively, p < 0.05). The K mono values were also lower in hypertrophic myocardium than in nonhypertrophic and normal myocardium (0.05 +/- 0.010 versus 0.066 +/- 0.0011 and 0.065 +/- 0.017 per min, respectively, p < 0.05). The %FDG/%perfusion values in hypertrophic myocardium did not differ significantly from those in nonhypertrophic myocardium (0.96 +/- 0.10 versus 1.02 +/- 0.07).


CONCLUSIONS
Myocardial ischemia at rest is observed less frequently in patients with HCM. Impairment of oxidative and glucose metabolism may precede decreased blood flow. Primary metabolic impairment is considered to be dominant in hypertrophic myocardium.
Tadamura
E
E
Department of Nuclear Medicine, Kyoto University, Faculty of Medicine, Japan.
Tamaki
N
N
Matsumori
A
A
Magata
Y
Y
Yonekura
Y
Y
Nohara
R
R
Sasayama
S
S
Yoshibayashi
M
M
Kamiya
T
T
Konishi
J
J
D000085:Acetates; D000328:Adult; D002250:Carbon Radioisotopes; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging / Q000378:metabolism*; D016022:Case-Control Studies; D003847:Deoxyglucose / Q000031:analogs & derivatives; D004452:Echocardiography; D004734:Energy Metabolism; D005260:Female; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D017202:Myocardial Ischemia / Q000000981:diagnostic imaging; D009206:Myocardium / Q000378:metabolism*; D014055:Tomography, Emission-Computed
D000085:Acetates; D002250:Carbon Radioisotopes; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D003847:Deoxyglucose