RETROGRADE AND INDEPENDENTLY ARTICULATABLE NESTED CATHETER SYSTEMS FOR COMBINED IMAGING AND THERAPY DELIVERY OR OTHER USES

Devices, systems, and methods are provided for image-guided interventional procedures and other uses. Nested articulated catheter shaft systems may have an imaging catheter with an ultrasound transducer supported by a fluid-driven articulated sheath portion. Drive fluid can be transmitted distally along an asymmetric sheath via eccentric passages to an articulated portion of the imaging catheter distal of a port. An articulated shaft supporting a therapeutic tool can be advanced within a working lumen of the imaging sheath to the port so that the tool is within a field of view of the transducer. The fluid transmission channels may take much less cross-sectional area of the sheath than a mechanical pull-wire system, allowing the nested sheath/shaft system to provide safer access to a chamber of the heart and to facilitate precise independent control over 3D ultrasound imaging and image-guided structural heart therapies or the like.