Measurement of Right Ventricular Volumes Before and After Atrial Septal Defect Closure Using Multislice Computed Tomography Rafic F. Berbarie, MD a , Azam Anwar, MD a , William D. Dockery, MD b , Paul A. Grayburn, MD a , Baron L. Hamman, MD c , Ravi C. Vallabhan, MD a , and Jeffrey M. Schussler, MD a,†, * 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 measur- ing 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 recal- culated. 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 cm 3 /m 2 (p  0.0007). In conclusion, this report is the first to describe the utility of MSCT to demonstrate RV EDV reduction after ASD closure. © 2007 Elsevier Inc. All rights reserved. (Am J Cardiol 2007;99:1458 –1461) Volume measurements of the right ventricle are clinically important, particularly in the assessment of congenital heart disease. 1 A variety of imaging methods are currently used to obtain such measurements, but each has limitations with regard to measuring the complex shape of the right ventri- cle. 2 Multislice computed tomography (MSCT) has been validated in studies to accurately measure right ventricular (RV) volumes. 3–5 Atrial septal defects (ASDs), the second most common congenital heart defects seen in adults, can lead to varying degrees of RV volume overload and failure. Improvements in RV volumes after ASD closure have been previously demonstrated using echocardiography. 6 Whether or not MSCT may also be used in a similar manner has not been studied. Therefore, we assessed the hypothesis that MSCT could be used as a new method to evaluate RV end-diastolic volume (EDV) before and after the closure of an ASD. Methods and Results From June 2004 to March 2006, we prospectively enrolled 10 consecutive patients with ASDs. All patients had signif- icant shunts calculated by oximetry (Q p :Q s 1.8) and were scheduled to undergo closure of their ASDs with either a transcatheter or a surgical approach. Patients then under- went MSCT for the purpose of calculating their RV EDVs. Exclusion criteria included pregnancy, renal insufficiency, an inability to follow directions or hold the breath, atrial fibrillation, intolerance to  blockers, or an allergy to con- trast. The mean age was 50 years (range 19 to 69). Seven patients were women. Informed consent was obtained from all patients, and the study protocol was approved by the institutional review board at our hospital. All of the studies were completed at our institution with either 16- or 64-slice MSCT (Lightspeed 16 or Lightspeed VCT 64, General Electric Systems, GE Healthcare, Mil- waukee, Wisconsin). A volume data set was acquired for 16-slice computed tomography (12  0.75 mm collimation, gantry rotation time 420 ms, table feed 2.8 mm/rotation, tube voltage 120 kV) and 64-slice computed tomography (64  0.625 mm collimation, gantry rotation time 350 ms, table feed 9.6 mm/rotation, tube voltage 120 kV), covering the distance from the carina to the diaphragm, with retro- spective electrocardiographic gating for image reconstruc- tion. If the patient’s heart rate at rest was 65 beats/min, he or she was started on an oral  blocker 2 to 3 days before the scan. Intravenous  blockers were given for heart rates 65 beats/min at the time of the examination. Nonionic contrast (approximately 100 to 120 ml) was injected at a rate of 3 to 4 ml/s and timed to fill the right ventricle. Images were reconstructed with a slice thickness of 0.625 mm in late diastole. Three-dimensional models of the right ventricle were then created at a workstation using commercially available software (AW Workstation, GE Healthcare, Waukesha, Wisconsin) from a combination of long- and short-axis a Department of Internal Medicine, Division of Cardiovascular Disease, b Department of Radiology, and c Department of Cardiothoracic Surgery, Baylor University Medical Center, Dallas, Texas. Manuscript received September 29, 2006; revised manuscript received and accepted December 21, 2006. *Corresponding author: Tel: 214-841-2030; fax: 214-841-2015. E-mail address: jschussler@heartplace.com (J.M. Schussler). † Conflict of interest: Dr. Schussler is a speaker for GE Healthcare, Waukesha, Wisconsin. 0002-9149/07/$ – see front matter © 2007 Elsevier Inc. All rights reserved. www.AJConline.org doi:10.1016/j.amjcard.2006.12.075