Recommendations are presented for standardized imaging planes and display conventions for two-dimensional echocardiography in the dog and cat. Three transducer locations ("windows") provide access to consistent imaging planes: the right parasternal location, the left caudal (apical) parasternal location, and the left cranial parasternal location. Recommendations for image display orientations are very similar to those for comparable human cardiac images, with the heart base or cranial aspect of the heart displayed to the examiner's right on the video display. From the right parasternal location, standard views include a long-axis four-chamber view and a long-axis left ventricular outflow view, and short-axis views at the levels of the left ventricular apex, papillary muscles, chordae tendineae, mitral valve, aortic valve, and pulmonary arteries. From the left caudal (apical) location, standard views include long-axis two-chamber and four-chamber views. From the left cranial parasternal location, standard views include a long-axis view of the left ventricular outflow tract and ascending aorta (with variations to image the right atrium and tricuspid valve, and the pulmonary valve and pulmonary artery), and a short-axis view of the aortic root encircled by the right heart. These images are presented by means of idealized line drawings. Adoption of these standards should facilitate consistent performance, recording, teaching, and communicating results of studies obtained by two-dimensional echocardiography. nary Internal Medicine (ACVIM) has recognized the need to adopt profession-wide standards for nomenclature, display and recording, interpretation, communication, and publication of images obtained using this technology. Accordingly, a Committee on Echocardiography, composed of experienced veterinary cardiac ultrasonographers, was formed to produce a report of recommendations for standards in veterinary echocardiography. This report, one of several to be developed by the committee, contains recommendations for standards for routine transthoracic two-dimensional echocardiography (2DE) in the dog and cat. The principles are generally applicable to other species, including horses and other farm animals, but more study and experience will be required before detailed recommendations can be made for these species. The recommendations presented in this report have been reviewed and approved by consensus of the diplomates of the Specialty

Recommendations are presented for standardized imaging planes and display conventions for two‐dimensional echocardiography in the dog and cat. Three transducer locations (“windows”) provide access to consistent imaging planes: the right parasternal location, the left caudal (apical) parasternal location, and the left cranial parasternal location. Recommendations for image display orientations are very similar to those for comparable human cardiac images, with the heart base or cranial aspect of the heart displayed to the examiner's right on the video display. From the right parasternal location, standard views include a long‐axis four‐chamber view and a long‐axis left ventricular outflow view, and short‐axis views at the levels of the left ventricular apex, papillary muscles, chordae tendineae, mitral valve, aortic valve, and pulmonary arteries. From the left caudal (apical) location, standard views include long‐axis two‐chamber and four‐chamber views. From the left cranial parasternal location, standard views include a long‐axis view of the left ventricular outflow tract and ascending aorta (with variations to image the right atrium and tricuspid valve, and the pulmonary valve and pulmonary artery), and a short‐axis view of the aortic root encircled by the right heart. These images are presented by means of idealized line drawings. Adoption of these standards should facilitate consistent performance, recording, teaching, and communicating results of studies obtained by two‐dimensional echocardiography.

Permanent transvenous cardiac pacemakers were implanted in 40 dogs. Electrocardiographic diagnoses included persistent atrial standstill (3 dogs), sick sinus syndrome (8 dogs), and high-grade second-degree or third-degree atrioventricular (AV) block (29 dogs). Thirteen dogs were alive and well 4 to 42 months after pacemaker implantation (mean, 16.9 months). The mean and median survival times of the 26 dogs that died or were euthanatized during the study were 17.9 months and 13 months, respectively. Most of these dogs succumbed to problems unrelated to the arrhythmia and pacemaker implant. One dog was lost to follow-up. Complications associated with permanent transvenous pacemaker implantation included lead dislodgement, infection, hematoma formation, skeletal muscle stimulation, ventricular arrhythmia, migration of the pulse generator, and skin erosion. Lead dislodgement was the most common complication, occurring in 7 of 9 dogs paced using untined electrode leads and in 6 of 30 dogs paced using tined leads. Lead dislodgement did not occur in the only dog paced using an actively fixed endocardial lead. It was concluded that permanent transvenous cardiac pacing is a feasible, less traumatic alternative to epimyocardial pacing in dogs, but that successful use of this technique requires careful implantation technique and anticipation of the potential complications. (Journal of Veterinary Internal Medicine 1991; 5:322-331) THE FIRST totally implantable artificial cardiac pacemakers were developed more than 30 years ago.' Since then, the equipment and techniques available to accomplish artificial cardiac pacing have changed dramatially.^-^ One of the most important technologic advances in artificial pacemaker design has been the development of durable pacing and sensing endocardial electrodes (leads) that can be introduced into the heart from a peripheral vein6-* Before the development of permanent transvenous leads, reliable artificial cardiac pacing could only be accomplished by surgical implantation of an epimyocardial electrode. Currently, transvenous

We reviewed the indications for age and breeds of dogs who received transvenous endocardial artificial pacemaker (AP) implantation (n 5 105) and complications and survival thereafter at a single institution over a 6-year period. A third-degree atrioventricular (AV) block (59%) and sick sinus syndrome (SSS; 27%) were the most common indications, along with a highgrade second-degree AV block (9%) and atrial standstill (5%). The most common breeds identified were Labrador Retriever (n 5 16; 11 with a third-degree AV block), American Cocker Spaniel (n 5 14; 10 with SSS), and Miniature Schnauzer (n 5 13; all with SSS). Common presenting complaints were syncope (n 5 66) and exercise intolerance or lethargy (n 5 25). Half of the dogs (n 5 52) had a history of acute onset of clinical signs (,2 weeks). Mean survival time for the 60 dogs who died during the study period was 2.2 years (range, 0.1-5.8 years). Major complications occurred in 13% of dogs and included lead displacement (n 5 7), sensing problems that led to syncope (n 5 3), infection at the pacemaker site (n 5 1), bleeding (n 5 1), and ventricular fibrillation during implantation (n 5 1; successfully defibrillated). Minor complications occurred in 11 dogs (11%). The success rate of transvenous AP implantation was comparatively high (all dogs survived the first 48 hours), and the complication rate was comparatively low when compared with a previous multicenter study, most likely because of how commonly the procedure was performed and supervisory experience.