In this paper, we describe advances in the design, fabrication and testing of two-dimensional catheter-mounted arrays for real-time three-dimensional (RT3-D) intracardiac echocardiography (ICE). These include a 7 Fr (2.3 mm O.D.), 112 element 2-D array utilizing a non-coaxial ribbon-based cabling technology. The 7 Fr transducer has a center frequency of 5 MHz, with a -6 dB fractional bandwidth of 30% and insertion loss of 80 dB (including 1 m of cable). The small size of the catheter enables RT3-D ICE from within the coronary sinus, a standpoint not possible with previous ICE catheters. We present in vivo sheep images of cardiac anatomy obtained from within the CS including the left and right atria, aorta, coronary arteries, and pulmonary veins. We also present simultaneous long and short axis views of the left ventricle, mitral valve, and left atrium with the 7 Fr catheter positioned in the right ventricle. We have also developed a 14 Fr (4.5 mm O.D.) forward-viewing 2-D array intracardiac probe containing an integrated working lumen for interventional device delivery. We present in vivo images of cardiac anatomy and simultaneous device delivery including the manipulation of a 0.35 mm diameter guidewire into the CS. We have also recently investigated the feasibility of using the forward-viewing probes to visualize the deployment of an abdominal aortic graft.