The cardiac disease ubiquitously associated in Duchenne Muscular Dystrophy (DMD) has traditionally been considered a progressive dilated cardiomyopathy (DCM). However, left ventricular (LV) dilatation as measured with cardiac MRI has not been a consistent finding in this population, even as circumferential strain (ε cc) declines with advancing disease. We hypothesized that a distinct pattern of changes in LV geometry, during the course of ε cc decline, distinguishes DMD associated heart disease from DCM. Using CMR, LV end-diastolic volume (EDV), mass (LVM), ejection fraction, ε cc and myocardial delayed enhancement (MDE) were determined in DMD patients and normal control subjects. The LV Remodeling Index (LVRI) was calculated as the ratio of LV Mass to Volume (LVM/EDV). Statistical comparisons between all LV parameters and genotype were also performed. Median LVRI in DMD (n = 127) and control subjects (n = 41) were different (0.75 vs. 0.65, P = 0.0150) but within normal range. Furthermore, the median LVRI in DMD boys with reduced LV systolic function was significantly reduced compared to those with normal LV systolic function (0.64 vs. 0.75, P = 0.0974). However, the presence of MDE was associated with a lower median LVRI (0.57 vs. 0.76, P = 0.0471). Regression analysis showed no significant correlation between ε cc and LVRI (r = -0.03). The LVRI of DMD patients is unexpectedly normal and not correlated with ε cc. Based on these findings, DMD-associated heart disease exhibits a unique remodeling pattern distinct from DCM.
- Cardiac MRI
- Dilated Cardiomyopathy
ASJC Scopus subject areas
- Radiology Nuclear Medicine and imaging
- Cardiology and Cardiovascular Medicine