CARDIAC INVOLVEMENT IN FEMALE CARRIERS OF DUCHENNE OR BECKER MUSCULAR DYSTROPHY

Introduction: The significance of abnormal cardiac measures in asymptomatic females who harbor dystrophin gene mutations is controversial. Methods: Echo-measures of ventricular function were compared with published norms in a cross-sectional study of 130 (age, 39615.7 years) "carriers" of Duchenne or Becker muscular dystrophy (DMD/BMD). Correlations between cardiomyopathy (CM) and mutation, creatine kinase (CK) levels, age, and muscle symptoms were investigated. Results: Depending on definition, CM prevalence was 3-33%. Ejection fraction (Simpson method) was< 55% in 9 (13%) and <40% in 2 (2.9%). Eleven (8.5%) had wall motion abnormalities. Left ventricular end-systolic dimensions were increased in 7 (5.7%) and end-diastolic in 17 (13.9%). CM did not correlate with mutation type, DMD or BMD phenotype, CK level, muscle symptoms, or age. Conclusions: Occult CM can be found by screening in DMD/BMD carriers. Its lack of age-correlation suggests that not all abnormalities progress. Optimum screening schedules require a better understanding of progressive CM.