Images in Cardiovascular Medicine Multimodality Imaging of a Gerbode Defect

A 76-year-old woman with a history of aortic valvereplacement was referred for echocardiography for routine postoperative evaluation. Transthoracic echocar-diogram revealed evidence of an intracardiac shunt be-tween the left ventricle (LV) and the right atrium (RA) (Figure 1A). A transesophageal echocardiogram confirmed the presence of an LV to RA shunt consistent with a Gerbode defect (Figure 1B and 1C). To further define shunt anatomy and to quantify the shunt ratio, cardiac MRI was performed. The cardiac MRI demonstrated abnormal flow from the LV to the RA (Figure 2A and 2B) as well as normal right ventricular size and function. By phase contrast imaging technique, the shunt volume was determined to be 28.4 cc/cardiac cycle corresponding to 2 L/min (Figure 2C). In addition, the pulmonary-to-systemic flow ratio was calculated as 1.7/1.0