title: Impact of surgical pulmonary valve replacement on ventricular mechanics in children with repaired tetralogy of Fallot.
abstract: Impaired ventricular myocardial mechanics are observed in patients with repaired tetralogy of Fallot (rTOF). Effects of pulmonary valve replacement (PVR) on ventricular remodeling are controversial. The objective was to assess the impact of surgical PVR on ventricular mechanics in pediatric patients after rTOF. Speckle-tracking analysis was performed in 50 rTOF children, aged 12.6 ± 3.3 years, pre-operatively and 14.5 ± 2.2 months post-PVR. Early post-operative studies 2.2 ± 0.6 months post-PVR were performed in 28 patients. Cardiac magnetic resonance (CMR) pre- and post-PVR was collected. Mid-term post-PVR right ventricular (RV) longitudinal strain increased above pre-operative strain (-19.2 ± 2.7 to -22.0 ± 3.0%, p < 0.001) with increases observed in individual RV segments. Left ventricular (LV) strain did not differ at medium-term follow-up. LV and RV longitudinal strain was reduced early post-operatively, followed by recovery of biventricular systolic strain by mid-term follow-up. CMR RV end-diastolic indexed volumes correlated with RV strain pre-operatively (r = 0.432, p = 0.005) and at mid-term follow-up (r = 0.532, p = 0.001). Volume-loaded RVs had reduced early RV basal longitudinal strain compared to pressure-loading conditions. Reversed basal counterclockwise rotation was associated with lower mid-term global LV and basal RV strain compared to patients with normal rotation. An increase in mid-term global and regional RV strain beyond pre-operative values suggests positive RV remodeling and adaptation occurs in children post-PVR. Patients with larger pre-operative RV volumes had lower RV strain post-operatively. The impact of LV rotation on RV mechanics highlights the presence of ventriculo-ventricular interactions. These findings have important clinical implications in pediatric rTOF patients towards identifying pre-operative factors that predict RV post-operative remodeling.
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Yim
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Mertens
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: C T
authors.initials: CT
authors.lastname: Morgan
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: M K
authors.initials: MK
authors.lastname: Friedberg
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: L
authors.initials: L
authors.lastname: Grosse-Wortmann
authors.affiliation: The Labatt Family Heart Centre, The Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. andreea.dragulescu@sickkids.ca.
authors.forename: A
authors.initials: A
authors.lastname: Dragulescu
mesh_terms: D000222:Adaptation, Physiological; D000293:Adolescent; D001696:Biomechanical Phenomena; D006348:Cardiac Surgical Procedures / Q000009:adverse effects; D002648:Child; D003430:Cross-Sectional Studies; D004452:Echocardiography; D005260:Female; D019918:Heart Valve Prosthesis Implantation / Q000009:adverse effects; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009200:Myocardial Contraction; D015588:Observer Variation; D011237:Predictive Value of Tests; D011664:Pulmonary Valve / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011665:Pulmonary Valve Insufficiency / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology / Q000601:surgery*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013314:Stress, Mechanical; D013771:Tetralogy of Fallot / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right; D020257:Ventricular Remodeling
keywords: Myocardial deformation; PVR; Pulmonary valve replacement; Strain; TOF; Tetralogy of Fallot