Magnetic resonance imaging to assess acute changes in atrial and ventricular parameters after transcatheter closure of atrial septal defects

Purpose: 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. Materials and 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 per-formed before and within 24 hours after transcatheter ASD closure. Right atrial (RA) and left atria] (LA) dimensions, as well as right (RV) and left (LM 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). Conclusion: 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.