Duchenne (DMD) and Becker muscular dystrophies (BMD) are rare inherited conditions where there is progressive skeletal muscle degeneration and loss and premature death. The conditions typically also involve the heart where the loss of muscle causes the heart to weaken and progressively fail in its pumping function. This cardiac pump failure can be detected by an echocardiogram performed by a paediatric cardiologist. However children and adolescents with muscular dystrophy can also develop problems with the cardiac rhythm which causes the heart to beat irregularly or to go to fast.
Researchers from Houston, Texas have investigated the frequency and type of heart rhythm problems in young people with Duchenne muscle distrophy or Becker muscular dystrophy by using ECG Holter recorders which allow to measure heart rate for uninterrupted periods of 24 or 48 hours while the child or adolescent is at home.
The authors of the research observed that 44% of children with Duchenne muscle dystrophy and over half of children with Becker muscular dystrophy had arrhythmias detected by the heart rhythm monitors. The arrhythmias were simple in the majority of children but one in 10 DMD and one in 4 BMD had more significant arrhythmias (supra-ventricular tachycardia of ventricular tachycardia).
Presence of arrhythmias was associated with poorer cardiac pumping function and older age.
The study is important as it further stresses the importance of routine screening for arrhythmias in children with Duchenne muscle dystrophy and Becker muscular dystrophy, particularly those with worsening cardiac function.