Equine Echocardiography Beyond Standard Views: Catheter Guidance and Anatomy

Standard echocardiographic images in horses have been well described in literature. They serve to assess overall cardiac function mainly based upon 2D, M-mode and Doppler. Standard images often do not allow accurate assessment of congenital or acquired malformations or specific lesions (endocarditis, mass) as these can be located anywhere in the heart. Finding these abnormalities and identifying the precise anatomical location can be a real challenge for the clinician as it requires correct anatomical interpretation of non-standard ultrasound images and insight into the 3D anatomy. Over the last years, catheter-based intracardiac procedures (pressure monitoring, transvenous electrical cardioversion, electrophysiology, pacemaker lead placement, biopsy, guide-wire retrieval, 3D mapping, ablation) have become increasingly important in equine cardiology. Although it is applicable to obtain some kind of guidance, fluoroscopy does not deliver enough anatomical detail for many catheter-based procedures and requires very high radiation doses. Therefore, catheter-based interventions almost entirely depend on echocardiographic guidance. In this presentation tips and tricks are provided regarding the procedure itself, ultrasound equipment, optimal imaging windows, probe manipulation, interpretation of the resulting (non-)standard images, identifying (new) anatomical landmarks and how to recognize and ‘follow’ catheters through the cardiovascular system, starting from the venous or arterial access point, until the heart and the downstream vessels (pulmonary artery, aorta). For each anatomical region, the link between anatomy, probe manipulation, echocardiographic landmarks and image interpretation will be given and common pitfalls are highlighted. The presentation is full of pictures and videos of cardiac anatomy, equine heart phantoms and echocardiography. Imaging techniques include mainly 2D and doppler but also 3D and intracardiac ultrasound so that it covers basic as well as more advanced procedures.