Jg. Crilley et al., Magnetic resonance spectroscopy evidence of abnormal cardiac energetics inXp21 muscular dystrophy, J AM COL C, 36(6), 2000, pp. 1953-1958
Citations number
37
Categorie Soggetti
Cardiovascular & Respiratory Systems","Cardiovascular & Hematology Research
OBJECTIVES Our aim was to measure the cardiac phosphocreatine to adenosine
triphosphate ratio (PCr/ATP) noninvasively in patients and carriers of Xp21
muscular dystrophy and to correlate the results with left ventricular (LV)
function as measured by echocardiography.
BACKGROUND Duchenne and Becker muscular dystrophy (the Xp21 dystrophies) ar
e associated with the absence or altered expression of dystrophin in cardia
c and skeletal muscles. They are frequently complicated by cardiac hypertro
phy and dilated cardiomyopathy. The main role of dystrophin is believed to
be structural, but it may also be involved in signaling processes. Defects
in energy metabolism have been found In skeletal muscle in patients with Xp
21 muscular dystrophy. We therefore hypothesized that a defect in energy me
tabolism may be part of the mechanism leading to the cardiomyopathy of Xp21
muscular dystrophy.
METHODS Thirteen men with Becker muscular dystrophy, 10 female carriers and
23 control subjects were studied using phosphorus-31 magnetic resonance sp
ectroscopy and echocardiography.
RESULTS The PCr/ATP was significantly reduced in patients (1.55 +/- 0.37) a
nd carriers (1.37 +/- 0.25) as compared with control subjects (2.44 +/- 0.3
3; p < 0.0001 for both groups). The PCr/ATP did not correlate with LV eject
ion fraction or mass index.
CONCLUSIONS Altered expression of dystrophin leads to a reduction in the PC
r/ATP. Since this reduction did not correlate with indexes of left ventricu
lar function, this raises the possibility of a direct link between altered
dystrophin expression and the development of cardiomyopathy in such patient
s. (C) 2000 by the American College of Cardiology.