This paper describes a system which allows the exploration of a detailed geometric 3D model of the cardiovascular tree in a scalable virtual environment in real time. Positioning a virtual camera inside the vascular structure for a virtual fly-through can provide a better understanding of the global structure. Vascular bifurcations of high curvature with acute angles and narrow pathways can be easily detected. Especially in a 3D environment, steering and navigation using traditional devices, such as keyboard and mouse, is not always intuitive. This article addresses this need and describes a novel approach to guided, interactive navigation utilizing a multi-functional gamepad for controlling camera and viewpoint.