title: The effect of right ventricular myocardial remodeling on ventricular function as assessed by two-dimensional speckle tracking echocardiography in patients with tetralogy of Fallot: a single center experience from China.
abstract: BACKGROUND
  Published correlations between histological abnormalities and right ventricular (RV) function, as evaluated by speckle tracking echocardiography (STE), are scarce in patients with tetralogy of Fallot (TOF). The purpose of the study is to assess age-associated differences in the effect of RV myocardial remodeling on ventricular function in patients with TOF.
  
  
  METHODS
  Operatively resected crista supraventricularis muscle from 30 patients (median age 12months) undergoing intracardiac repair of TOF were studied by light microscopy. The patients were divided into younger (age at surgery ≤12months) and older (age at surgery >12months) subgroups. The RV global longitudinal peak systolic strain (GLS), strain rate (GLSRs) and early diastolic strain rate (GLSRe) were measured by two-dimensional STE before and 6months after repair.
  
  
  RESULTS
  The histopathological data revealed hypertrophy of the cardiomyocytes, a thickened endocardium, and increased interstitial and perivascular collagen in RV, which were associated with older age at the time of repair. The RV global systolic and diastolic functions in patients with repaired TOF were increased compared with the preoperative values. The RV cardiomyocyte diameter and collagen volume fraction (CVF) correlated with the preoperative GLS, GLSRs and GLSRe, respectively, in the younger patients (r1=-0.566, P1=0.018; r2=-0.493, P2=0.004; r3=-0.504, P3=0.039). The RV cardiomyocyte diameter and CVF correlated with preoperative GLS, GLSRs and GLSRe, respectively, in the older patients (r1=-737, P1=0.004; r2=-0.588, P2=0.035; r3=-0.812, P3=0.001). The correlation of the RV cardiomyocyte diameter with the postoperative GLS and GLSRe (r1=-665, P1=0.036; r2=-0.787, P2=0.007) and the CVF with the postoperative GLSRs and GLSRe (r1=-762, P1=0.002; r2=-0.713, P2=0.004) were identified only in the older patients. Multivariate analysis indicated that the age at repair was an independent predictor of postoperative GLSRs and GLSRe in all of the patients (β=-0.449, P=0.041; β=-0.607, P=0.004).
  
  
  CONCLUSIONS
  The effect of RV myocardial remodeling on preoperative RV function was more pronounced in the older patients with TOF than in the younger ones. Preoperative myocardial remodeling affected the postoperative RV function in the older but not in the younger patients. The age at the time of surgical repair was the independent determinant of the postoperative RV myocardial function.
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Mingxing
authors.initials: M
authors.lastname: Xie
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Yuman
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China; Department of Medicine, George Washington University Medical Center, 2150 Pennsylvania Avenue, N.W., Washington, DC 20037, USA. Electronic address: tcheng@mfa.gwu.edu.
authors.forename: Tsung O
authors.initials: TO
authors.lastname: Cheng
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Xinfang
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Cardiovascular Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Nianguo
authors.initials: N
authors.lastname: Dong
authors.affiliation: Department of Pathology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Xiu
authors.initials: X
authors.lastname: Nie
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Lu
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: YaLi
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: He
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of Ultrasonography, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430022, People's Republic of China.
authors.forename: Pingping
authors.initials: P
authors.lastname: Ren
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D002681:China / Q000453:epidemiology; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D013771:Tetralogy of Fallot / Q000000981:diagnostic imaging* / Q000453:epidemiology / Q000601:surgery; D016278:Ventricular Function, Right / Q000502:physiology*; D020257:Ventricular Remodeling / Q000502:physiology*; D055815:Young Adult
keywords: Myocardial remodeling; Right ventricular function; Speckle tracking echocardiography; Tetralogy of Fallot