Intracardiac echocardiography (ICE) is finding increased use in interventional cardiology, but its significant learning curve for clinicians and imaging specialists in combination with increased costs act as barriers to wider use when compared with well-established modalities such as transesophageal echocardiography or fluoroscopy. Specific challenges for users include difficulty with spatial orientation, unfamiliar views of cardiac anatomy, limited field of view and the ergonomics of catheter placement. Here we present a framework for fusing 3D ultrasound (US) volumes captured in-vivo using a novel 360-degree 4D-ICE system into panoramic volumes with extended spatialinformation and improved signal-to-noise ratio to provide anatomical context for clinicians. Our approach uses 3D registration initialized with five degrees of freedom electromagnetic tracking and electrocardiogram (ECG) gating to create these panoramic volumes for visualization of key anatomical landmarks as well as positional information for the operator during complex cardiac procedures. Experimental results using in-vivo cardiac US pullback sequences of porcine specimens demonstrate the efficacy of the approach. We also compare the resulting panoramic volumes with pre-operative computed tomography (CT) scans to validate identified structures.