title: Systolic-diastolic functional coupling in healthy children and in those with dilated cardiomyopathy.
abstract: Systolic and diastolic function affect dilated cardiomyopathy (DCM) outcomes. However, systolic-diastolic coupling, as a distinct characteristic, may itself affect function but is poorly characterized. We hypothesized that echocardiographic left ventricular (LV) longitudinal systolic tissue velocities (S') correlate with diastolic longitudinal velocities (E') and that their relationship is associated with ventricular function and that this relationship is impaired in pediatric DCM. We analyzed data from the Pediatric Heart Network Ventricular Volume Variability study, using linear regression and generalized additive modeling to assess relationships between S' and E' at the lateral and septal mitral annulus. We explored relationships between the systolic:diastolic (S:D) coupling ratio (S':E' relative to age) and ventricular function. Up to 4 echocardiograms from 130 DCM patients (mean age: 9.3 ± 6.1 yr) and 1 echocardiogram from each of 591 healthy controls were analyzed. S' and E' were linearly related in controls (r = 0.64, P < 0.001) and DCM (r = 0.83, P < 0.001). In DCM, the magnitude of association between S' and E' was reduced with progressive ventricular remodeling. The S:D ratio was more strongly associated with LV function in controls vs. DCM. The septal S:D ratio was higher (presumed worse) in DCM vs. controls (0.69 ± 0.13 vs. 0.62 ± 0.12, P = 0.001). A higher septal S:D ratio was associated with worse LV dimensions (parameter estimate: 0.0061, P = 0.004), mass (parameter estimate: 0.0074, P = 0.002), ejection fraction (parameter estimate: -0.0303, P = 0.024), and inflow propagation (parameter estimate: -0.3538, P < .001). S:D coupling becomes weaker in DCM with LV remodeling and dysfunction. The S:D coupling ratio may be useful to assess coupling, warranting study in relation to patient outcomes.
authors.affiliation: Hospital for Sick Children, Toronto, Ontario, Canada; mark.friedberg@sickkids.ca.
authors.forename: Mark K
authors.initials: MK
authors.lastname: Friedberg
authors.affiliation: Boston Children's Hospital, Boston, Massachusetts;
authors.forename: Renee
authors.initials: R
authors.lastname: Margossian
authors.affiliation: New England Research Institutes, Watertown, Massachusetts;
authors.forename: Minmin
authors.initials: M
authors.lastname: Lu
authors.affiliation: The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania;
authors.forename: Laura
authors.initials: L
authors.lastname: Mercer-Rosa
authors.affiliation: Duke University Medical Center, Durham, North Carolina;
authors.forename: Heather T
authors.initials: HT
authors.lastname: Henderson
authors.affiliation: Medical University of South Carolina, Charleston, South Carolina;
authors.forename: Arni
authors.initials: A
authors.lastname: Nutting
authors.affiliation: Boston Children's Hospital, Boston, Massachusetts;
authors.forename: Kevin
authors.initials: K
authors.lastname: Friedman
authors.affiliation: Primary Children's Hospital Utah, Salt Lake City, Utah;
authors.forename: Kimberly M
authors.initials: KM
authors.lastname: Molina
authors.affiliation: Columbia University Medical Center, New York, New York; and.
authors.forename: Karen
authors.initials: K
authors.lastname: Altmann
authors.affiliation: Washington University, St. Louis Children's Hospital, St. Louis, Missouri.
authors.forename: Charles
authors.initials: C
authors.lastname: Canter
authors.affiliation: New England Research Institutes, Watertown, Massachusetts;
authors.forename: Lynn A
authors.initials: LA
authors.lastname: Sleeper
authors.affiliation: Boston Children's Hospital, Boston, Massachusetts;
authors.forename: Steven D
authors.initials: SD
authors.lastname: Colan
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D002648:Child; D003971:Diastole / Q000502:physiology*; D004452:Echocardiography / Q000379:methods; D005260:Female; D006352:Heart Ventricles / Q000473:pathology*; D006801:Humans; D008297:Male; D013318:Stroke Volume / Q000502:physiology; D013599:Systole / Q000502:physiology*; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: cardiomyopathy; diastole; echocardiography; pediatrics; systole