Figure Legends
Figure 1a-h. Example of TTE and CMR Images. TTE images in the 4-chamber (A) and mid-ventricular short axis (B) with suboptimal images due to poor acoustic windows. CMR LGE images in the 4-chamber (C) and short axis (D) with LGE (bright areas delineated by red arrows) in the same patients at later stage of DMD-CM. Cine Images in the 4-chamber (E) and short axis (F) with good quality images by CMR despite poor TTE acoustic windows. Tagged images for myocardial strain in the 4-chamber (G) and short axis (H).
Figure 2. Scatter Plot of DMD Patients by Age and LVEF. LVEF abnormality (define as <55% delineated by red dotted horizontal line) is uncommon before age 10 years (highlighted transparent red rectangular box) and incidence increases with age.
Figure 3. Plot of Percentage of DMD Patients with LVEF <55% by Age. The percent of DMD patients with LVEF below 55% is uncommon before 10 years of age and increased with Age.
Figure 4. Plot of Percentage of DMD Patients with LGE by Age. The percent of DMD patients with LGE increased with age and starts as early as 7 years.
Figure 5. Concept of Myocardial Strain. Displacement and Velocity measures motion as the heart empties and fill. Myocardial strain analysis detects myocardial contractility. Positive strain is stretching of the myocardium (radial direction visualized as thickening of the myocardium, yellow oval and increased thickness of the rectangle). Negative strain is contraction of the myocardium (can occur in the longitudinal along the long axis of the heart or circumferential in the oblique axis of the heart, red oval) follows the direction of the myocardial fiber.
Figure 6a-h. LGE Pattern in DMD is Unique. Normal myocardium remain dark after giving contrast agent as shown in 4-chamber (A) and short axis (B). In patients with heart attack or myocardial infarction the area that is injured or has scar remains bright and is typically in the subendocardial region (inner part of the muscle) encircled by the dashed red lines and delineated by the white areas from the base to the apical sections of the heart (C-D respectively). Similarly the fibrosis in DMD is white after contrast as encircled by pink dashed and highlighted by pink arrows and in contrast it is in the outer surface of the heart or subepicardium (F-H).
Figure 7a-h. LGE Burden Increased with Age. Normal subject with no LGE (all black delineated by yellow arrows) in the 4-chamber (A) and short axis (B). Young DMD patient with small area of LGE (bright area delineated by red arrows) in 4-chamber (C) and short mid-ventricular short axis (D). Older DMD patient with increased LGE (bright area delineated by red arrows) with preserved LVEF in 4-chamber (E) and short mid-ventricular short axis (F). Older DMD patient with late stage DMD-CM with dilated chamber and extensive LGE involving nearly full thickness of the myocardium in multiple segments including the septum (bright area delineated by red arrows) in 4-chamber (G) and short mid-ventricular short axis (H).
Figure 8a-l. LGE and T1 Mapping by CMR. T1 is abnormal in DMD and increased with age. Normal patient with no LGE (no bright areas, yellow arrows) in the 4-chamber (B), short axis (A) and normal T1 of 1155 millisecond. Young DMD patient with no LGE in the 4-chamber (B), short axis (A) and with slightly increased T1 of 1180 millisecond. Younger DMD patient with LGE (bright areas delineated by red arrows) in the 4-chamber (B), short axis (A) and with elevated increased T1 of 1230 millisecond. Older DMD patient with extensive LGE including the septum (bright areas delineated by red arrows) in the 4-chamber (B), short axis (A) and with very elevated increased T1 of 1355 millisecond.
Figure 9. Case Example of Progressive DMD-CM. Patient followed at age 5 years with yearly with normal LVEF (blue arrow) with no cardiac therapy. LVEF declined to 48% at age 14 years (yellow arrow) and despite escalation of care LVEF continued to decline including milrinone infusion (red arrows) resulting in placement of a left ventricular assist device with continued severe LV dysfunction (red arrows) and now right ventricular dysfunction.