Objectives: This study sought to evaluate the natural history of occult cardiac dysfunction in Duchenne muscular dystrophy (DMD). Background: Duchenne muscular dystrophy is characterized by progressive cardiac dysfunction and myocardial fibrosis late in the disease process. We hypothesized that left ventricular myocardial peak circumferential strain (εcc) would decrease in DMD before global systolic functional abnormalities regardless of age or ventricular ejection fraction (EF). Methods: We evaluated cardiac magnetic resonance image (MRI) data from 70 DMD patients and 16 aged-matched control subjects. Standard imaging data included steady-state free precession short-axis cine stack images, cine myocardial tagged images, and myocardial delayed enhancement (MDE) (an indicator of myocardial fibrosis) sequences. Analysis was performed with QMASS (Medis Medical Imaging Systems, Leiden, the Netherlands) and HARP (Diagnosoft, Palo Alto, California) software. The DMD patient data were subdivided by age (<10 or >10 years), EF (>55% or <55%), and the presence or absence of MDE. Results: The DMD patients with normal EF had reduced εcc at an early age (<10 years) compared with control subjects (p < 0.01). The DMD patients age >10 years with normal EF had further decline in εcc compared with younger DMD patients (p < 0.01). There was further decline in εcc with age in patients with reduced EF (p < 0.01) without MDE. The oldest patients, with both reduced EF and positive MDE, exhibited the lowest εcc. None of the patients had ventricular hypertrophy. Conclusions: Myocardial strain abnormalities are prevalent in young DMD patients despite normal EF, and these strain values continue to decline with advancing age. Strain analysis in combination with standard MRI and MDE imaging provides a means to stratify DMD cardiomyopathy.
- Duchenne muscular dystrophy
- cardiac magnetic resonance imaging
- circumferential strain
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine