title: High prevalence of incomplete right bundle branch block in facioscapulohumeral muscular dystrophy without cardiac symptoms.
abstract: The exact prevalence and nature of cardiac involvement in facioscapulohumeral muscular dystrophy (FSHD) is unknown. Nevertheless, the current opinion is that symptomatic cardiac disease is rare. We performed a cardiac screening [electrocardiogram (ECG) and echocardiography in the event of ECG abnormalities] in 75 genetically confirmed, ambulant FSHD patients without cardiac symptoms, with an eight-year follow-up of 57 patients, and compared the findings with results of previously performed cardiac screenings in the normal population. Baseline ECG demonstrated incomplete right bundle branch block (RBBB) in 33%, complete RBBB in 4%, and other minor abnormalities in 16%. Echocardiography showed no abnormalities. No significant changes were found after eight years of follow-up. Comparison with ECG abnormalities in the normal population showed a higher prevalence of incomplete RBBB (9.7 times higher) and of complete RBBB (4.8 times higher) in FSHD patients. This study in cardiac asymptomatic FSHD patients shows i) increased prevalence of incomplete RBBB in the absence of cardiomyopathy; ii) no progression of these abnormalities during eight years of follow-up. We conclude that FSHD patients without cardiac complaints do not need specific cardiac screening or surveillance. Furthermore, the increased prevalence of incomplete RBBB in the absence of cardiomyopathy suggests a selective involvement of the His-Purkinje system in FSHD.
authors.forename: Gaby Pons
authors.initials: GP
authors.lastname: van Dijk
authors.forename: Elly
authors.initials: E
authors.lastname: van der Kooi
authors.forename: Anthony
authors.initials: A
authors.lastname: Behin
authors.forename: Joep
authors.initials: J
authors.lastname: Smeets
authors.forename: Janneke
authors.initials: J
authors.lastname: Timmermans
authors.forename: Silvère
authors.initials: S
authors.lastname: van der Maarel
authors.forename: George
authors.initials: G
authors.lastname: Padberg
authors.forename: Nicol
authors.initials: N
authors.lastname: Voermans
authors.forename: Baziel
authors.initials: B
authors.lastname: van Engelen
mesh_terms: D000328:Adult; D002037:Bundle-Branch Block / Q000150:complications* / Q000000981:diagnostic imaging / Q000453:epidemiology*; D009202:Cardiomyopathies / Q000175:diagnosis; D004452:Echocardiography; D004562:Electrocardiography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020391:Muscular Dystrophy, Facioscapulohumeral / Q000150:complications*; D015995:Prevalence