Comprehensive assessment of morphology and severity of atrial septal defects in adults by CT.

BACKGROUND

Cardiac CT is an excellent tool for evaluating the anatomy of a secundum atrial septal defect (ASD). However, a comprehensive assessment of its usefulness, including measurement of the pulmonary to systemic blood flow ratio in secundum ASD patients, has not been performed.

OBJECTIVE

Therefore, this study was designed to evaluate the usefulness of CT for assessing the hemodynamics of secundum ASD in adults compared with transesophageal echocardiography (TEE), transthoracic echocardiography, and invasive catheterization.

METHODS

Fifty adult patients with secundum ASD were enrolled. Cardiac CT scans (128-slice multidetector CT instrument) were acquired. These were followed by 2-dimensional reconstruction of the secundum ASDs to determine the defect size, the rim length between the outer edge of the defect, and the pulmonary to systemic blood flow (Qp/Qs) ratio.

RESULTS

The maximum sizes of the secundum ASDs derived from CT and TEE studies were comparable (21.2 ± 8.0 vs. 20.0 ± 7.3 mm; P = .41; r = 0.960; P < .001). The rim lengths for the aortic, mitral, and tricuspid valves; the inferior vena cava; and posterior atrium were also comparable between CT and TEE measurements. The mean Qp/Qs ratio that was derived from CT measurements was comparable with that found by invasive catheterization (2.3 ± 0.7 vs. 2.3 ± 0.8; P = .73; r = 0.786; P < .001).

CONCLUSION

Cardiac CT is feasible for assessing pathology and the severity of secundum ASD in adults.