Prevalence of type 1 Brugada ECG pattern after administration of Class 1C drugs in patients with type 1 myotonic dystrophy: Myotonic dystrophy as a part of the Brugada syndrome.

Background: Both type 1 myotonic dystrophy (MD1) and Brugada syndrome (BrS) may be complicated by conduction disturbances and sudden death. Spontaneous BrS has been observed in MD1 patients, but the prevalence of drug-induced BrS in MD1 is unknown.

Objective: The purpose of this study was to prospectively assess the prevalence of type 1 ST elevation as elicited during pharmacologic challenge with Class 1C drugs in a subgroup of MD1 patients and to further establish correlations with ECG and electrophysiologic variables and prognosis.