Acute myopathy of intensive care in a child after heart transplantation.

PURPOSE: Acute myopathy of intensive care has been described infrequently in children and never after organ transplantation. We report a case of acute myopathy of intensive care in a child after heart transplantation.

CLINICAL FEATURES: An 11-yr-old girl, with no previous medical history, developed acute cardiomyopathy leading to cardiac shock. Family history revealed four cases of unidentified myopathy and/or cardiomyopathy. Preoperatively, while muscle biopsy was near normal, myocardial biopsy revealed non specific mitochondrial disorders. A few days after heart transplantation, she developed acute hypotonia and flaccid quadriplegia, consistent with the diagnosis of acute myopathy of intensive care. Nerve conduction studies were normal, electromyography showed myopathic changes and a new muscle biopsy from quadriceps femoris showed severe loss of myosin filaments and ATPase activity in type 2 fibres. A large laboratory screening failed to demonstrate a metabolic disease or a known myopathy. Muscle strength recovered progressively in three weeks allowing home discharge. A few months later, she was free of symptoms and muscle biopsy showed full histopathological recovery.

CONCLUSION

Acute myopathy of intensive care can occur in children after heart transplantation. It should be suspected in the presence of muscle weakness and difficulty in weaning from ventilatory support. Electromyography confirmed a myogenic process and muscle biopsy allowed diagnosis. Full clinical and histopathological recovery usually occur within three weeks.