title: Ventricular strain changes in monochorionic twins with and without twin-to-twin transfusion syndrome.
abstract: OBJECTIVE
  The objective of the study was to investigate whether vector velocity imaging (VVI), a non-Doppler speckle tracking ultrasound technology, is feasible in twin pregnancies and can aid management of twin-twin transfusion syndrome (TTTS).
  
  
  METHODS
  Twenty-seven women pregnant with monochorionic diamniotic twins affected by TTTS and 28 monochorionic pregnancies that did not develop TTTS were included in a prospective case-control study at a fetal medicine center. Fetal echocardiograms were recorded with dummy electrocardiography to retain original frame rates when exported for offline speckle tracking analysis using Syngo-VVI software (Siemens Corp, Munich, Germany). Right and left ventricular (LV) free wall Lagrangian strain was measured from the original coordinates. Within-twin pair ventricular strain differences including relationship to Quintero staging and response to laser therapy for TTTS were analyzed by Wilcoxon signed-rank test.
  
  
  RESULTS
  The VVI strain measurements could be analyzed in 182 of 200 TTTS and 96 of 112 non-TTTS control ventricles. Within-pair strain was concordant in non-TTTS controls. Recipient LV strain was reduced at all Quintero stages compared with donors (P < .01). Recipient right ventricular strain was reduced only in stages 3 and 4 (P < .01). Strain improved at a median of 2 weeks following successful laser therapy. Intertwin differences in strain were independent of weight discordance.
  
  
  CONCLUSIONS
  Recipient LV strain is reduced in stages 1 and 2 TTTS. Within-pair strain discordance may distinguish early TTTS from growth discordance and guide timing of and management following treatment.
authors.affiliation: Division of Cancer, Faculty of Medicine, Imperial College, London, UK.
authors.forename: Marisa C
authors.initials: MC
authors.lastname: Taylor-Clarke
authors.forename: Hikoro
authors.initials: H
authors.lastname: Matsui
authors.forename: Michael
authors.initials: M
authors.lastname: Roughton
authors.forename: Ruwan C
authors.initials: RC
authors.lastname: Wimalasundera
authors.forename: Helena M
authors.initials: HM
authors.lastname: Gardiner
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D004452:Echocardiography; D005240:Feasibility Studies; D005260:Female; D020567:Fetal Weight; D005330:Fetofetal Transfusion / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D053685:Laser Therapy; D011247:Pregnancy; D011446:Prospective Studies; D018570:Risk Assessment; D014430:Twins, Monozygotic; D016216:Ultrasonography, Prenatal / Q000379:methods*; D055815:Young Adult