title: Myocardial Strain and Strain Rate in Kawasaki Disease: Range, Recovery, and Relationship to Systemic Inflammation/Coronary Artery Dilation.
abstract: BACKGROUND
  Kawasaki Disease (KD), a systemic vasculitis of medium sized vessels, is the most common cause of acquired heart disease among children in the developed world. Some KD patients demonstrate echocardiographic evidence of depressed myocardial mechanics. However, the incidence, etiology, and reversibility of abnormal mechanics in KD patients remain undefined.
  
  
  RESULTS
  We retrospectively studied 41 KD patients and measured myocardial strain and strain rate by velocity vector imaging from pre-treatment and convalescent echocardiograms. Pre-treatment procalcitonin, C-reactive protein (CRP), and coronary artery z-scores were obtained in all patients and compared between the groups with preserved versus depressed acute phase mechanics. The change in mechanics between the acute and convalescent phases was also assessed. Patients with initially low longitudinal strain improved by the convalescent period (mean difference - 4.0%; p<0.005) with the greatest improvement occurring in patients with the lowest initial strain (-7.3%; p<0.05). Patients with higher initial strain did not change significantly by the convalescent period. Patients with lower longitudinal and circumferential strain demonstrated higher median procalcitonin levels (1.2 vs. 0.3 ng/mL; p<0.05 and 1.8 vs. 0.4 ng/mL; p<0.05 respectively) and a trend towards higher CRP, but no difference in coronary artery z-scores. Strain rate was not associated with inflammatory markers or coronary artery z-scores.
  
  
  CONCLUSIONS
  The range of strain found in our cohort was large. Improvement in mean strain was driven primarily by patients with lower initial strain. Lower strain was associated with increased markers of systemic inflammation, but not proximal coronary artery changes.
authors.affiliation: Department of Pediatrics and Section of Cardiology, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Frank
authors.affiliation: Department of Pediatrics and Section of Cardiology, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Jesse
authors.initials: J
authors.lastname: Davidson
authors.affiliation: Department of Biostatistics, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Suhong
authors.initials: S
authors.lastname: Tong
authors.affiliation: Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Blake
authors.initials: B
authors.lastname: Martin
authors.affiliation: Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Heather
authors.initials: H
authors.lastname: Heizer
authors.affiliation: Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Marsha S
authors.initials: MS
authors.lastname: Anderson
authors.affiliation: Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Mary P
authors.initials: MP
authors.lastname: Glode
authors.affiliation: Department of Pediatrics and Section of Infectious Diseases, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Samuel R
authors.initials: SR
authors.lastname: Dominguez
authors.affiliation: Department of Pediatrics and Section of Cardiology, Children's Hospital Colorado/University of Colorado, Denver, USA.
authors.forename: Pei-Ni
authors.initials: PN
authors.lastname: Jone
keywords: Aneurysm; Contractility; Echocardiography; Mechanics; Myocardial edema; Procalcitonin