Myocardial Strain and DMD-associated Cardiac Disease
In DMD-CM, myocardial strain, an indicator of local myocardial
deformation can detect occult cardiac disease early in the course of DMD
despite normal LVEF 32,
38, 48,
107. It has been shown that CMR derived
εcc is an early robust indicator of cardiac dysfunction
and can detect occult ventricular dysfunction in young DMD patients with
normal EF (>55%)48,
49, 53,
54, 107.
CMR-derived peak left ventricular circumferential strain
(εcc) is abnormal early in DMD despite normal EF, and
further depressed εcc magnitude is associated with
development of overt cardiac dysfunction and presence of myocardial
fibrosis 108. The
decrease in εcc despite preserved EF, suggest greater
sensitivity of εcc for disease detection compared to
LVEF. Thus, εcc is a sensitive, reliable biomarker of
both subtle and overt cardiac dysfunction in DMD then LVEF82.