A 56-year-old woman with a history of paroxysmal atrial fibrillation, moderate mitral regurgitation, and symptoms of heart failure presented for robotic-assisted minimally invasive mitral valve repair. Intraoperative transesophageal echocardiography (TEE) confirmed moderate mitral regurgitation with a cleft between the P2 and P3 segments of the posterior mitral valve leaflet. The patient's right internal jugular vein was cannulated with 2 introducers for placement of a percutaneous retrograde cardioplegia catheter (Edwards Lifesciences, Irvine, CA) and a pulmonary artery drain (Edwards Lifesciences). Consent was obtained from the patient for this report.TEE was used to guide the coronary sinus catheter using standard techniques with the midesophageal bicaval view and the midesophageal 4-chamber view. 1 However, during multiple attempts by the attending anesthesiologist, the coronary sinus catheter missed the coronary sinus orifice and was placed into the right ventricle, as demonstrated by pressure tracing. Furthermore, when the catheter did appear to engage the coronary sinus, as demonstrated by standard 2-dimensional (D) TEE, it appeared to bow. This bowing suggested misalignment of the coronary sinus catheter with the coronary sinus. At this point, 3-D imaging, using the 3-D zoom modality (Philips iE33, Philips Medical Systems, Andover, MA), was used to provide better orientation of the right atrium and the coronary sinus. Images were obtained by starting with a standard midesophageal 4-chamber view and enabling the 3-D zoom function while centering on the tricuspid valve. The 3-D zoom box was enlarged to cover the right atrium and slightly below the tricuspid valve, and the 3-D zoom imaging mode was enabled. The 3-D zoom image was then rotated to obtain an en face view of the coronary sinus.The following steps were then performed, as demonstrated in Video 1. (Please see video clips available at www.anesthesia-analgesia.org; see Supplemental Digital Content 1, http://links.lww.com/AA/A50.) First, the coronary sinus was imaged en face in the right atrium (Part 1). A graphic illustration of this view is compared with a TEE still frame in Figure 1. Second, the coronary sinus catheter was inserted in the right atrium and appeared adjacent to the coronary sinus ostium (Part 2). After the second clip was obtained, the catheter was slightly withdrawn, rotated in a counterclockwise fashion, and advanced. The coronary sinus catheter was then imaged within the coronary sinus (Part 3). Of note, when the coronary sinus catheter was moved, significant artifact from the catheter obscured the image and the actual movement of the catheter into the sinus was not recorded. The image was recorded only after the catheter was in the sinus. The successful placement of the coronary sinus catheter in the coronary sinus was confirmed by ventricularization of the coronary sinus pressure waveform with slow inflation of the coronary sinus catheter balloon and by imaging the coronary sinus with contrast fluoroscopy (Fig. 2). The last part...