title: Magnetic resonance imaging to assess acute changes in atrial and ventricular parameters after transcatheter closure of atrial septal defects.
abstract: OBJECTIVE
  To evaluate acute changes in atrial and ventricular parameters by the use of cardiac magnetic resonance imaging (MRI) in patients with percutaneous transcatheter atrial septal defects (ASD) closure.
  
  
  METHODS
  The study included 14 patients (six males and eight females, 45 +/- 18 years) with congenital ASD. Cardiac MRI (1.5T Philips Intera CV) was performed before and within 24 hours after transcatheter ASD closure. Right atrial (RA) and left atrial (LA) dimensions, as well as right (RV) and left (LV) ventricular end-diastolic (ED) volumes were determined. Atrial size was assessed by planimetry of the maximum RA and LA areas in a standard four-chamber view, and ventricular volumes were calculated according to a modified Simpson's rule in short-axis views.
  
  
  RESULTS
  The mean RA decreased significantly from 27.6 +/- 6.4 cm(2) before closure to 24.4 +/- 5.6 cm(2) after the procedure (P = 0.0018), whereas the LA area did not change (24.1 +/- 4.7 cm(2) vs. 23.8 +/- 5.2 cm(2), P = 0.76). The RV volumes, volume index, and ejection fraction (EF) decreased significantly from 229 +/- 64 mL to 181 +/- 43 mL (P < 0.001, average reduction = 19% +/- 15%), from 126.0 +/- 37.2 mL/m(2) to 96.6 +/- 28.6 mL/m(2) (P < 0.0001) and from 64 +/- 5% to 58% +/- 7% (P = 0.01), respectively. The LV volumes and volume index remained unchanged (114 +/- 25 mL vs. 118 +/- 22 mL, P = 0.18, 63.5 +/- 13.5 mL/m(2) vs. 63.0 +/- 17.4 mL/m(2), P = 0.83). Left-right shunting decreased from 40% +/- 15% to 9% +/- 15% (P < 0.001).
  
  
  CONCLUSIONS
  Cardiac MRI can reveal detailed information on acute changes in shunt fraction and ventricular dimensions after ASD closure. ASD closure by percutaneous transcatheter device implantation results within 24 hours in a significant reduction of shunt fraction, RA and RV sizes, and RV function, whereas LA and LV dimensions remain unchanged.
authors.affiliation: Cardiology Division, Department of Internal Medicine III, University of Tübingen, Tübingen, Germany.
authors.forename: Christof
authors.initials: C
authors.lastname: Burgstahler
authors.forename: Jochen
authors.initials: J
authors.lastname: Wöhrle
authors.forename: Matthias
authors.initials: M
authors.lastname: Kochs
authors.forename: Thorsten
authors.initials: T
authors.lastname: Nusser
authors.forename: Christine
authors.initials: C
authors.lastname: Löffler
authors.forename: Markus
authors.initials: M
authors.lastname: Kunze
authors.forename: Martin
authors.initials: M
authors.lastname: Höher
authors.forename: Meinrad P
authors.initials: MP
authors.lastname: Gawaz
authors.forename: Vinzenz
authors.initials: V
authors.lastname: Hombach
authors.forename: Nico
authors.initials: N
authors.lastname: Merkle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D006328:Cardiac Catheterization; D016009:Chi-Square Distribution; D004562:Electrocardiography; D005260:Female; D006344:Heart Septal Defects, Atrial / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D007091:Image Processing, Computer-Assisted; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D008875:Middle Aged; D016276:Ventricular Function