title: Late ventricular geometry and performance changes of functional single ventricle throughout staged Fontan reconstruction assessed by magnetic resonance imaging.
abstract: OBJECTIVE
  We sought to test the hypothesis that late ventricular geometry and performance changes occur in functional single ventricles as they progress through staged Fontan reconstruction.
  
  
  BACKGROUND
  Indexes of ventricular geometry and performance are important in evaluating the functional state of the heart. Magnetic resonance imaging determines these indexes in complex ventricular shapes with minimal geometric assumptions. Previous studies have shown that 1 week after hemiFontan, the mass/volume ratio markedly increases.
  
  
  METHODS
  Multiphase, multislice, spin echo (n = 5) and cine (n = 30) magnetic resonance imaging was performed in 35 patients with a functional single ventricle (1 week to 12 years old) at various stages of Fontan reconstruction (15 in the pre hemiFontan stage, 11 after [6 to 9 months] the hemiFontan procedure and 9 after [1 to 2 years] the Fontan procedure). Volume and mass were calculated at end-systole and end-diastole. Ventricular output was then obtained. Ventricular centroid motion was also calculated.
  
  
  RESULTS
  No difference was noted (power > 72%) from the pre hemiFontan stage to 6 to 9 months after the hemiFontan procedure in (mean +/- SD) end-diastolic volume (104 +/- 24 vs. 123 +/- 40 cc/m2), mass (171 +/- 46 vs. 202 +/- 61 g/m2), ventricular output (7.9 +/- 2.2 vs. 6.6 +/- 2.4 liters/min per m2) or centroid motion (6.9 +/- 2.8 vs. 6.7 +/- 2. mm/m2). Patients in the Fontan group demonstrated a marked decrease in all indexes, indicating significant volume unloading and decrease in mass and ventricular performance. Mass/volume ratio was not significantly different among all three groups.
  
  
  CONCLUSIONS
  No geometric and performance changes from the volume-loaded stage are noted 6 to 9 months after the hemiFontan procedure; however, major changes occur 1 to 2 years after the Fontan procedure. The dramatic changes in the mass/volume ratio seen early after the hemiFontan procedure were not detected at 6 to 9 months. Furthermore diminution of mass, volume and ventricular performance are present at least 2 years after the Fontan procedure.
authors: The Children's Hospital of Philadelphia, Division of Cardiology, Philadelphia, Pennsylvania 19104, USA.
authors: M A
authors: MA
authors: Fogel
authors: P M
authors: PM
authors: Weinberg
authors: A J
authors: AJ
authors: Chin
authors: K E
authors: KE
authors: Fellows
authors: E A
authors: EA
authors: Hoffman
mesh_terms: D016022:Case-Control Studies; D002648:Child; D002675:Child, Preschool; D005500:Follow-Up Studies; D018729:Fontan Procedure / Q000379:methods; D006330:Heart Defects, Congenital / Q000175:diagnosis / Q000503:physiopathology* / Q000601:surgery*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging; D019028:Magnetic Resonance Imaging, Cine; D009200:Myocardial Contraction / Q000502:physiology; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D016276:Ventricular Function / Q000502:physiology*