Occult Cardiac Contractile Dysfunction in Dystrophin-Deficient Children Revealed by Cardiac Magnetic Resonance Strain Imaging

Abstract

Background-Duchenne muscular dystrophy (DMD) is an inherited disease characterized by early onset of skeletal muscle degeneration and progressive weakness. Although dilated cardiomyopathy may occur during adolescence, it is often undetected early in its course because of physical inactivity and generalized debilitation. The purpose of this study was to apply the technique of cardiac magnetic resonance (CMR) tagging to detect occult cardiac dysfunction in young subjects with DMD by measuring myocardial strain and torsion. Methods and Results-Thirteen DMD pediatric subjects without clinically apparent heart disease and 9 age-matched healthy males were recruited. Each was scanned on a 1.5-T clinical scanner to acquire contiguous short-axis planes from the apex to the mitral valve plane and then 3 tagged images at base, midventricle, and apex. Global and segmental myocardial net twist and circumferential strain were computed with the use of 2D homogeneous strain analysis. Ventricular torsion was computed by normalizing net twist by the distance from apex to mitral valve plane. DMD patients exhibited normal left ventricular volumes and ejection fractions but manifested reduced midventricular and basal cross-sectional global circumferential strain compared with the reference group (PϽ0.005). These alterations also appeared in segmental analyses in the septal, anterior, lateral, and inferior walls (PϽ0.05). Conclusions-In patients predisposed to cardiomyopathies because of dystrophinopathy, occult regional cardiac dysfunction can be diagnosed with CMR tagging. This method of strain imaging analysis may offer a sensitive approach for delineating the presence and progression of cardiovascular disease and for assessing therapies designed to modulate the onset and course of heart failure.

Occult Cardiotoxicity in Childhood Cancer Survivors Exposed to Anthracycline Therapy

“…32 The presence of myocardial strain abnormalities, as well as a serial decline in myocardial strain magnitude without a change in ejection fraction, has been previously reported in other forms of nonischemic cardiomyopathy. 14,[33][34][35] Our data provide evidence of similar findings in AIC subjects with reductions in regional performance in these subjects as demonstrated by low peak longitudinal (ε ιι ) and circumferential strain (ε cc ) magnitude in all segments of the myocardium. In contrast to the widespread segmental involvement demonstrated by CMR, speckle-tracking techniques by TTE demonstrated reductions limited to the anteroseptal and inferoseptal segments.…”

“…This difference likely reflects the enhanced sensitivity of CMR for the detection of subtle changes in intramural contractile function, as previously reported. 33 Postcontrast myocardial longitudinal relaxation time (T 1 ) mapping constitutes a novel technique for quantifying interstitial myocardial fibrosis, 16,36 a fundamental change associated with early pathological remodeling in the course of AIC. 5 An increasing number of studies have identified diffuse myocardial fibrosis in several cardiac disease states [36][37][38] with the use of various protocols for T1 mapping 16,23,36 and in pediatric patients exposed to anthracyclines.…”

Segmental Myocardial Strain of the Left Ventricle in Patients With Duchenne Muscular Dystrophy Using Two-Dimensional Speckle Tracking Echocardiography

“…patients manifested reduced mid-ventricular and basal cross-sectional global circumferential strain using the MR tagging method [14]. The two-dimensional speckle tracking echocardiography might easily measure the strain of the myocardium with increased spatial and temporal resolution in comparison to MR tagging strain analysis.…”

Tadalafil Treatment Delays the Onset of Cardiomyopathy in Dystrophin‐Deficient Hearts

“…Magnetic resonance imaging was also performed at ages 18 and 25 months to evaluate the peak circumferential myocardial strain of the LV, a very sensitive measure of myocardial distress. 25 For these measurements, the magnetic resonance image of the complete LV wall was partitioned into 6 segments ( Figure 5A). At 18 months ( Figure 5B), tadalafiltreated dogs showed improved circumferential myocardial strain values than untreated dogs in the anterior segment of the interventricular septum (segment 2).…”