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Ventricular dysfunction in type 1 myotonic dystrophy: electrical, mechanical, or both?

P Lindqvist1, S Mörner, B O Olofsson

  • 1Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden. per.lindqvist@medicin.umu.se

International Journal of Cardiology
|April 28, 2009
PubMed

Insights

Myotonic dystrophy type 1 (DM1) patients show impaired cardiac function, with asynchronous heart cavity movements. Early detection of these abnormalities may improve survival through resynchronization therapy.

Area of Science:

  • Cardiology
  • Genetics
  • Neuromuscular Disorders

Background:

  • Myotonic dystrophy type 1 (DM1) is a systemic disease impacting cardiac function.
  • Conduction disturbances are common cardiac abnormalities in DM1, potentially leading to sudden death.

Purpose of the Study:

  • To assess electrical and mechanical cardiac functions in DM1 patients.
  • To identify cardiac abnormalities that may explain sudden cardiac death in DM1.

Main Methods:

  • Echocardiography with myocardial Doppler and ECG recordings were used.
  • 36 DM1 patients and 16 controls were studied.

Main Results:

  • DM1 patients exhibited reduced left ventricular (LV) systolic function and prolonged cardiac time intervals, indicating asynchronous LV cavity function.
  • Right ventricular (RV) strain and velocities were also reduced.
  • Prolonged LV total isovolumic time (t-IVT) correlated with PR interval and QRS duration; some patients showed myocardial causes for asynchrony.

Conclusions:

  • DM1 patients display significant asynchronous cardiac function, beyond modest impairments in conventional LV measurements.
  • Abnormalities are often linked to prolonged PR interval or broad QRS duration, but a minority suggest a myocardial basis.
  • Early identification of these cardiac issues may guide therapy, potentially improving survival with resynchronization.
Abstract

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