The coronary sinus (CS) has become a clinically important structure especially through its role in providing access for different cardiac procedures. Fluoroscopy with or without two dimensional transesophageal echocardiography (2DTEE) is the widely used method for guidance. A 78-year-old female patient was undergoing percutaneous CARILLON mitral annuloplasty device therapy for chronic severe symptomatic mitral regurgitation. After insertion of the coronary sinus catheter through the right internal jugular vein, multiple trials for coronary sinus cannulation guided by fluoroscopy and 2DTEE were unsuccessful. So, real time three-dimensional zoom mode was used to get the anatomically oriented en face view of the interatrial septum from the right atrial perspective. The CS ostium was identified then the catheter was reintroduced through the SVC into the right atrium then easily navigated to cannulate the coronary sinus ostium.