Pacemaker implantation: This is a suitable treatment for patients with bradyarrhythmias (third degree AV block, sick sinus syndrome, and others) who are exhibiting clinical signs. Most pacemakers are placed using a transvenous route to place a lead in the right ventricle – most often using the jugular vein. Recovery from this minimally invasive procedure is fast, but patients must be rested for approximately 1 month post-operatively to minimise the risk of complications, which occur in a small proportion of dogs. Most dogs have a good quality of life and long-term survival after pacemaker implantation, but must have at least annual pacemaker check-ups with a cardiologist.
Occlusion of a patent ductus arteriosus: Closing a PDA by an open thoracotomy is associated with a high-risk of haemorrhage and thereby a relatively high death rate. In contrast, occlusion of a PDA via a transvascular route (most often using an arterially placed Amplatz Canine Duct Occluder; ACDO) has a very high success rate (98% have complete occlusion at 24h post-operatively) and a very low rate of complications. Dogs are often discharged from hospital at 24h after the procedure, and the vast majority have a good long-term survival and an incredibly good prognosis. Some dogs, where the PDA has been diagnosed relatively late in life, may require more long-term monitoring, treatment, or both.
Dilation of a pulmonic or aortic stenosis: Balloon dilation of a stenotic pulmonic valve has a high success rate and a relatively low mortality rate. Like other minimally invasive procedures, recovery is quick and post-operative morbidity is very low indeed. Prognosis is variable, dependent on how responsive the stenosis is to ballooning, but most dogs have an improvement in clinical signs for some years, if not lifelong. Techniques to balloon dilate aortic stenosis are in their infancy, but have shown some some promise in dogs with severe clinical signs. Experience with this is limited to a handful of centres in Europe, so it is worth discussing it with your local Cardiologist prior to referral.
Trans-oesophageal echocardiography: TOE is useful for intraoperative guidance of interventional procedures, such as PDA occlusion or septal defect occlusion. It may also be used for assessment of mitral repair surgery intraoperatively, or quantification of cardiac output and volume status for dogs undergoing mechanical ventilation. As such, its availability is limited to few centres, usually where these techniques are commonplace.
Real-time 3D echocardiography: Often referred to as “4D echo” – with real time being the fourth dimension – this modern echo technique has limited availability. It is most often used clinically to assess patients with complex congenital heart disease, or dogs with degenerative valve disease prior to surgical valve repair.
Mitral valve repair surgery: Open-heart surgery performed under cardio-pulmonary bypass, to repair the mitral valve and reduce the severity of mitral regurgitation. In future, this may be the standard of care for dogs with degenerative mitral valve disease. At this time, experience is very limited – however, results are encouraging. Surgery is limited to three centres worldwide; the JASMINE Veterinary Cardiovascular Medical Centre in Japan (Dr Masami Uechi), the Clinic Veterinaire Bozon de Versailles (Drs Sabine and Jean-Hugh Bozon, with Dr Uechi visiting), and the Royal Veterinary College in London (Prof Dan Brockman, who trained with Dr Uechi). Concerns over financial cost and short-term risk is often prohibitive for owners, but with better long-term survival than medical treatment can offer, surgery is the right decision for some owners.