Early cardiac evaluation in children with non-specific mitochondrial disease with isolated mitochondrial respiratory chain complex I defect

Authors

  • Ran Baik,

    1. Department of Pediatrics, Gangnam Severance Hospital, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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  • Rita Yu,

    1. Department of Pediatrics, Gangnam Severance Hospital, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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  • Young Mock Lee,

    Corresponding author
    1. Department of Pediatrics, Gangnam Severance Hospital, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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  • Hoon Chul Kang,

    1. Department of Pediatrics, Gangnam Severance Hospital, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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  • Joon Soo Lee,

    1. Department of Pediatrics, Gangnam Severance Hospital, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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  • Heung Dong Kim

    1. Department of Pediatrics, Gangnam Severance Hospital, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Korea
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  • Conflict of interest: The authors have no conflicts of interest to declare.

Professor Young Mock Lee, Department of Pediatrics, Gangnam Severance Hospital, Severance Children's Hospital, Yonsei University College of Medicine, PO Box 1217, 712 Eonjuro, 146-92 Dogok-dong, Gangnam-gu, 135-720 Seoul, Korea. Fax: +82 2 3461 9475; email: ymleemd@yuhs.ac

Abstract

Aims:  We evaluated echocardiography and electrocardiography (ECG) results in children with non-specific mitochondrial disease (MD) in order to study early cardiac involvement, a well-known complication of the disease.

Methods:  Among non-specific MD children whose isolated mitochondrial respiratory chain complex I defect was confirmed by muscle biopsy and satisfied the criteria of MD, 27 who had no cardiac symptoms were evaluated by echocardiography and ECG.

Results:  Three (11.1%) out of the 27 non-specific MD patients had left ventricular ejection fraction of less than 55% and two of them (7.4%) had fractional shortening of less than 26%. ECG abnormalities were observed in 16 of the non-specific MD patients (59.3%). Prolongation of heart rate-corrected QT interval was seen in 11 (40.7%) and widening of the QRS interval in eight (29.6%). Left ventricular ejection fraction and fractional shortening of the patients were significantly decreased compared with those in the control group while heart rate-corrected QT interval was prolonged in the former group. QRS interval was more widened in non-specific MD patients, but without statistical significance.

Conclusion:  The potentially severe cardiac involvement observed in our subjects suggests that early cardiac evaluation after confirming the diagnosis of MD and regular follow-up tests should be strongly recommended in children even in cases without typical cardiac manifestations.

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