Left ventricular diastolic function in congenital myotonic dystrophy

Abstract

Objective-Examination of left ventricular function and conduction abnormalities in myotonic dystrophy. Design-Twelve patients (median age, 13.7 years) with myotonic dystrophy had detailed electrocardiography and echocardiography performed. Echocardiographic parameters were compared with body surface area (BSA) matched median normal values. Results-Fractionalshortening was slightly reduced (by 28-29%) in three patients and three patients had mild mitral valve prolapse. Diastolic function was abnormal; isovolumic relaxation time (IVRT) and duration of early filling were prolonged compared with control values (median IVRT, 74 v 61 ms). Peak E velocity was increased (median, 0.82 v 0.78 m/s) but atrial phase filling was normal. Heart rate was reduced (median, 68 v 81 beats/ min). Conduction abnormalities were common but showed no clear relations with diastolic abnormalities. Conclusions-Young patients with myotonic dystrophy have myocardial diastolic dysfunction as well as abnormal electrophysiology. The prognostic implications of such abnormalities require further study. (Arch Dis Child 1999;80:267-270)

Cardiac involvement and CTG expansion in myotonic dystrophy

“…A transthoracic echocardiography is useful as a screening-test when the diagnosis of a DM is made, but our retrospective study is in agreement with the observations of many others that systolic dysfunction seems to be quite uncommon in DM [4]. The ejection fraction was not statistically correlated with the CTG expansion.…”

“…The ejection fraction was not statistically correlated with the CTG expansion. Mitral valve prolapse is often described in patients with DM [2,4,12,23]. However in our series, there were only three patients with mitral valve prolapse.…”

“…A transthoracic echocardiography is useful as a screeningtest, but abnormalities of systolic function seem to be quite uncommon. As from diverse recent studies it is shown that diastolic dysfunction is a common finding in patients with DM, this should be examined more meticulously in the future, during this first screening test [4,9].…”

Congenital Myotonic Dystrophy

“…In a study of seven asymptomatic adolescences with CDM all had some ECG or echocardiographic abnormality with atrioventricular and intraventicular conduction defects in the majority [90]. Some echocardiography differences include mitral valve prolapse and fractional shortening reduction in later childhood [90,91]. In case series one can conclude that fatal arrhythmias are a common cause of mortality [41,55].…”

Cardiac Involvement in Primary Myopathies

“…The underlying mutation is an expanding trinucleotide (CTG repeat in the 3′ untranslated region of a serine-threonine kinase gene (DMPK) on chromosome 19q13.3 (table 1) [35]. The most frequent cardiac abnormalities in MD1 are impulse generation and propagation defects like AV block [36], prolonged QT interval, QRS prolongation, torsades de pointes [23, 37], myocardial thickening [38]and heart failure [39, 40]. Supra- and infra-Hisian conduction abnormalities may also be found in the mouse model of MD1 [41].…”