Measurement of Right Ventricular Volumes Before and After Atrial Septal Defect Closure Using Multislice Computed Tomography

Volumetric measurements of the right ventricle are helpful in patients with atrial septal defects (ASDs) in estimating the degree of right ventricular (RV) failure. They also may be important in following patients postoperatively after ASD closure. Traditional imaging modalities used to obtain such measurements have had limitations in measuring the complex shape of the right ventricle. Multislice computed tomography (MSCT) is a technique that provides excellent spatial resolution of the moving heart. This study was conducted to assess whether MSCT could be used to evaluate RV end-diastolic volume (EDV) before and after the closure of an ASD. From June 2004 to March 2006, 10 patients with ASDs underwent MSCT to calculate their RV volumes. The patients then had their ASDs closed by either a percutaneous or a surgical approach. Three months later, the patients' MSCT scans were repeated, and RV volumes were recalculated. EDV was approximated using 3-dimensional volume-rendered models of the right ventricle. At a mean follow-up of 3 months, a significant reduction in mean RV EDV, indexed for body surface area, was demonstrated, from 131 ± 31 to 83 ± 22 cm³/m² (p = 0.0007). In conclusion, this report is the first to describe the utility of MSCT to demonstrate RV EDV reduction after ASD closure.