title: Prognostic implications of the systolic to diastolic duration ratio in children with idiopathic or familial dilated cardiomyopathy.
abstract: BACKGROUND
  Childhood dilated cardiomyopathy (DCM) carries high morbidity and mortality. The echocardiographic systolic to diastolic (S:D) duration ratio, an indicator of global cardiac performance, is elevated in DCM; however, its prognostic implications have not been investigated in this population.
  
  
  RESULTS
  We investigated systolic and diastolic durations and the resultant S:D ratio using pulsed tissue Doppler imaging in children with idiopathic or familial DCM. We studied serial echocardiograms from presentation until the last follow-up echo. Results were compared with heart rate-matched controls and between DCM subgroups based on an acute or insidious presentation. The association between S:D ratio and death or need for transplant was analyzed. All analyses were adjusted for repeated measures per patient. We studied 200 serial echocardiograms of 48 children with DCM (7.0±6.0 years) and 25 controls. Adjusted for repeated measures through a compound symmetry covariance structure, the S:D ratio was higher in DCM patients (-0.425 [0.072]; P<0.001) because of shortened diastole. A S:D ratio >1.2 at presentation and on serial evaluation was associated with a hazard ratio of 10.5 (95% confidence interval, 3.9-27.8; P<0.001) for death or transplant. In combined multivariable analysis, a S:D ratio >1.2 remained significantly associated with hazard of death/transplant (hazard ratio, 9.1; P=0.04) after adjustment for ejection fraction (hazard ratio: 2.2 per -10%; P<0.001).
  
  
  CONCLUSIONS
  A high S:D ratio is associated with increased risk for death or need for transplant in children with DCM across the spectrum of heart rates and may be a useful prognostic index for serial evaluation of children with DCM.
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Tapas
authors.initials: T
authors.lastname: Mondal
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Cameron
authors.initials: C
authors.lastname: Slorach
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Cedric
authors.initials: C
authors.lastname: Manlhiot
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Wei
authors.initials: W
authors.lastname: Hui
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Paul F
authors.initials: PF
authors.lastname: Kantor
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Brian W
authors.initials: BW
authors.lastname: McCrindle
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada.
authors.forename: Luc
authors.initials: L
authors.lastname: Mertens
authors.affiliation: From the Division of Pediatric Cardiology, University of Toronto, The Labatt Family Heart Center, Hospital for Sick Children, Toronto, Ontario, Canada. mark.friedberg@sickkids.ca.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Friedberg
mesh_terms: D000293:Adolescent; D002311:Cardiomyopathy, Dilated / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D003971:Diastole; D015150:Echocardiography, Doppler; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009864:Ontario / Q000453:epidemiology; D011379:Prognosis; D012189:Retrospective Studies; D015996:Survival Rate / Q000639:trends; D013599:Systole; D016276:Ventricular Function / Q000502:physiology*
keywords: cardiomyopathy, dilated; echocardiography; pediatrics; prognosis