title: Relation between left ventricular regional radial function and radial wall motion abnormalities using two-dimensional speckle tracking in children with idiopathic dilated cardiomyopathy.
abstract: Left ventricular (LV) regional radial function and its relation to radial wall motion abnormalities have not been investigated in children with idiopathic dilated cardiomyopathy (IDC). Radial strain was measured using 2-dimensional speckle tracking to evaluate regional radial function and wall motion in 6 LV segments in 24 children (0 to 18 years old) with IDC and 16 healthy controls. Patients and controls were similar in age. Patients with IDC had higher heart rates (97 +/- 28 vs 77 +/- 19, p <0.05) and decreased ejection fraction (34 +/- 12% vs 66 +/- 7%, p <0.0001) compared with controls. Radial strain in all segments was significantly lower in patients with IDC. In IDC, average radial strain correlated well with ejection fraction (r = 0.8, p <0.0001). The SD of time to peak radial strain among 6 LV segments was significantly higher in patients with IDC than in controls (56 +/- 38 vs 15 +/- 12 ms, p <0.0001). Segmental peak radial strain correlated closely to time to peak radial strain in controls (r = 0.98, p = 0.0008), but less in patients with IDC (r = 0.76, p = 0.07). In conclusion, LV regional radial function is impaired in pediatric IDC, in association with increased radial dyssynchrony, revealing a possible important mechanism for LV dysfunction in these children.
authors.affiliation: Division of Paediatric Cardiology, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada. mark.friedberg@sickkids.ca
authors.forename: Mark Kevin
authors.initials: MK
authors.lastname: Friedberg
authors.forename: Cameron
authors.initials: C
authors.lastname: Slorach
mesh_terms: D000293:Adolescent; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D004452:Echocardiography / Q000379:methods*; D005260:Female; D006352:Heart Ventricles / Q000503:physiopathology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013318:Stroke Volume / Q000502:physiology