title: Myocardial atrophy in children with mitochondrial disease and Duchenne muscular dystrophy.
abstract: OBJECTIVE
  Mitochondrial disease (MD) and Duchenne muscular dystrophy (DMD) are often associated with cardiomyopathy, but the myocardial variability has not been isolated to a specific characteristic. We evaluated the left ventricular (LV) mass by echocardiography to identify the general distribution and functional changes of the myocardium in patients with MD or DMD.
  
  
  METHODS
  We retrospectively evaluated the echocardiographic data of 90 children with MD and 42 with DMD. Using two-dimensional echocardiography, including time-motion (M) mode and Doppler measurements, we estimated the LV mass, ratio of early to late mitral filling velocities (E/A), ratio of early mitral filling velocity to early diastolic mitral annular velocity (E/Ea), stroke volume, and cardiac output. A "z score" was generated using the lambda-mu-sigma method to standardize the LV mass with respect to body size.
  
  
  RESULTS
  The LV mass-for-height z scores were significantly below normal in children with MD (-1.02±1.52, P<0.001) or DMD (-0.82±1.61, P=0.002), as were the LV mass-for-lean body-mass z scores. The body mass index (BMI)-for-age z scores were far below normal and were directly proportional to the LV mass-for-height z scores in both patients with MD (R=0.377, P<0.001) and those with DMD (R=0.330, P=0.033). The LV mass-for-height z score correlated positively with the stroke volume index (R=0.462, P<0.001) and cardiac index (R=0.358, P<0.001).
  
  
  CONCLUSIONS
  LV myocardial atrophy is present in patients with MD and those with DMD and may be closely associated with low BMI. The insufficient LV mass for body size might indicate deterioration of systolic function in these patients.
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Tae Ho
authors.initials: TH
authors.lastname: Lee
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Lucy Youngmin
authors.initials: LY
authors.lastname: Eun
authors.affiliation: Division of Pediatric Cardiology, Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Jae Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hye Eun
authors.initials: HE
authors.lastname: Kwon
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Young-Mock
authors.initials: YM
authors.lastname: Lee
authors.affiliation: Division of Pediatric Neurology, Department of Pediatrics, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Heung Dong
authors.initials: HD
authors.lastname: Kim
authors.affiliation: Department of Rehabilitation Medicine and Rehabilitation Institute of Muscular Disease, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Seong-Woong
authors.initials: SW
authors.lastname: Kang
keywords: Duchenne muscular dystrophy; Echocardiography; Mitochondrial diseases; Myocardium