Particles such as thrombi, bullet fragments, and shrapnel can become trapped in a person's heart after migrating through the venous system, or by direct penetration. These cardiac foreign bodies pose a serious health risk as they can interfere with cardiovascular function. Conventional treatment often requires open heart surgery, cardiopulmonary bypass, and a long incision of the heart muscle, which come with significant risk and recovery time. To circumvent these disadvantages, we propose a minimally invasive surgical approach using 3D ultrasound to guide a dexterous robotic capture device. Analysis of the foreign body trajectory indicates highly erratic motion, rendering a robotic retrieval strategy based on direct pursuit of the tracked target infeasible. To provide a relatively slow robot with the ability to retrieve such a target, we propose alternative strategies based on guiding a robot to a salient capture location, and ambushing the target upon its reappearance. In this paper, we demonstrate the use of 3D transesophageal echocardiography (TEE) in tracking a foreign body in a beating heart phantom, computing a suitable capture location, and guiding a high dexterity robot to secure the target.