Intermittent pre-excitation-syndrome in facio-scapulo-humeral muscular dystrophy.

Pre-excitation-syndrome has not been reported as a phenotypic feature of facio-scapulo-humeral muscular dystrophy (FSH-MD). In a 39-year-old male with FSH-MD due to a reduced tandem repeat size in the D4Z4-locus on chromosome 4q35, cardiac involvement, manifesting as an incomplete right bundle-branch-block, tall T-waves in V 3-5, ST-elevation in V 2-4, and mild thickening of the left ventricular myocardium, was first recognised 10 years earlier. Follow-up at age 39 years revealed mild myocardial thickening, two intra-ventricular aberrant bands, and, surprisingly, intermittent pre-excitation on a routine electrocardiography. Cardiac involvement in FSH-MD may manifest as hypertrophic cardiomyopathy or various arrhythmias, of which one may be pre-excitation-syndrome.