The Present and Future of Intracardiac Echocardiography for Guiding Structural Heart Disease Interventions

Abstract

Novel transcatheter therapies for the treatment of valvular and congenital heart disease have increased exponentially in recent years. Parallel to this trend has been the need for multi-modality imaging in the planning, guidance, and evaluation of procedurerelated outcomes and complications. Echocardiography has played a pivotal role within the cardiac catheterization laboratory. Periprocedural invasive imaging with transesophageal echocardiography (TEE), in particular three-dimensional (3D) TEE, and more recently intracardiac echocardiography (ICE), is instrumental in providing the real-time, high-resolution images of intracardiac anatomy and physiology necessary to guide a multitude of structural heart disease (SHD) interventions. With new advances in ICE, this imaging technique is an attractive alternative to TEE with potential for continued growth. Within the last decade, echocardiography has guided an increasing number of structural heart procedures with improved success. Echocardiographic assessment of patients undergoing transcatheter therapy differs from that of patients with native or prosthetic valvular disease. The European Association of Echocardiography and American Society of Echocardiography have recognized the need for informed evaluation and have established guideline recommendations to include the newest SHD procedures: transcatheter aortic valve implantation, paravalvular regurgitation repair, and mitral valve interventions. As the field rapidly grows to incorporate other SHD therapies, there is an increasing demand for ultrasound imaging to be performed by the interventionalist and a reduced need for general anesthesia. In addition, there are other identifiable limitations to TEE. Visualization of more anterior structures may be limited due to a lack of far-field exposure and shadowing from surrounding structures may obscure the field of view. The TEE probe, on occasion, may partially obstruct the optimal fluoroscopic view for the interventionalist. Also, alternatives to TEE are sometimes necessary, especially in patients with absolute contraindications to esophageal intubation.