Associations between 'valentine' heart shape, atrial enlargement and cardiomyopathy in cats.

'Valentine' heart shape is a common qualifier used in veterinary radiology to describe a cardiac silhouette with focal enlargement at the level of the base of the heart in feline patients. Anecdotally, this sign has been thought to be related to biatrial enlargement and also to hypertrophic cardiomyopathy (HCM). However, to our knowledge, there has been no study performed to assess the association between cardiac chamber enlargement and cardiac disease with the 'valentine'-shaped heart. The aim of this study was to verify the association between the 'valentine' heart shape observed in ventrodorsal thoracic radiographs and the presence of singular or combined cardiac chamber enlargement, and also the presence and type of cardiomyopathy (CM) in cats. A search of the database of the Small Animal Veterinary Hospital of the University of Florida for cats with a radiology report of thoracic radiographs that contained the words 'valentine' and 'biatrial', and echocardiography performed within 1 week, was undertaken; 41 cases met the inclusion criteria. Eighty-two percent of the cats of the study sample had some form of CM. The 'valentine' heart shape was associated with biatrial enlargement in 41% of the patients in our study sample that had some form of CM and just 8% of cases diagnosed with HCM, suggesting that the 'valentine' heart shape has a low association with HCM or biatrial enlargement; however, it should be considered a sign of feline CM.

Cardiopulmonary Effects of Laparoscopic Ovariectomy of Variable Duration in Cats.

OBJECTIVE: To evaluate the cardiopulmonary effects of low-pressure (6 mmHg) peritoneal insufflation of varying duration in healthy cats during ovariectomy (OVE). STUDY DESIGN: Prospective, randomized study. ANIMALS: Female cats (n = 24). METHODS: After anesthesia induction, cats had short (Short LAP; n = 8) or long duration (Long LAP; n = 8) laparoscopic ovariectomy, or Open OVE (Open; n = 8) for comparison. Hemodynamic and pulmonary measurements were recorded after induction of anesthesia (T0), 5 minutes after abdominal insufflation had reached 6 mmHg of pressure (T1), after the 2nd ovary had been resected (T2), after abdominal decompression (T3), and at the end of anesthesia, after abdominal closure (T4). Hemodynamic and pulmonary variables were compared between groups. RESULTS: Low-pressure abdominal insufflation caused cardiopulmonary changes in cats. At T1 and T2, Long LAP and Short LAP caused a significant change in PvCO2 and RC when compared with Open. During T3, RC was lower only in Long LAP. At T2, there was decrease in SV, but not CO for Long LAP when compared with Open. CONCLUSIONS: Duration of insufflation was associated with worsening of negative cardiopulmonary effects; however, these effects were reversible and resolved by the end of the procedure.

Rhabdomyosarcoma associated with the lead wire of a pacemaker generator implant.

An 11-year-old female spayed Labrador Retriever was presented for a draining, painful subcutaneous mass palpated over a previously implanted pacemaker generator. Infection was suspected and the mass was removed surgically. On cut surface, the mass was friable and mottled tan to brown with firm pale tan nodules, surrounding the pacemaker lead wire adjacent to the pacemaker generator. Cytologic interpretation of impression smears was consistent with a sarcoma, and suggestive of a rhabdomyosarcoma due to the presence of strap-like cells. On histopathologic examination, a highly invasive nodular mass surrounded the pacemaker lead, composed of pleomorphic round, spindle and strap cells, and multinucleated giant cells. The population exhibited microscopic invasion into the deep portion of the fibrous capsule surrounding the pacemaker generator. There were tumor emboli within small to medium subcutaneous veins adjacent to the mass. Immunohistochemically, the neoplastic cells stained positive for α-sarcomeric actin and vimentin, and negative for α-smooth muscle actin, consistent with a rhabdomyosarcoma arising at the site of the pacemaker generator. To our knowledge, this is the first report of a rhabdomyosarcoma associated with the lead wire of a pacemaker generator in a dog.

Pharmacokinetics of oral dichloroacetate in dogs.

We characterized the pharmacokinetics and dynamics of dichloroacetate (DCA), an investigational drug for mitochondrial diseases, pulmonary arterial hypertension, and cancer. Adult Beagle dogs were orally administered 6.25 mg/kg q12h DCA for 4 weeks. Plasma kinetics was determined after 1, 14, and 28 days. The activity and expression of glutathione transferase zeta 1 (GSTZ1), which biotransforms DCA to glyoxylate, were determined from liver biopsies at baseline and after 27 days. Dogs demonstrate much slower clearance and greater inhibition of DCA metabolism and GSTZ1 activity and expression than rodents and most humans. Indeed, the plasma kinetics of DCA in dogs is similar to humans with GSTZ1 polymorphisms that confer exceptionally slow plasma clearance. Dogs may be a useful model to further investigate the toxicokinetics and therapeutic potential of DCA.

How to perform combined cutting balloon and high pressure balloon valvuloplasty for dogs with subaortic stenosis.

Subvalvular aortic stenosis (SAS) is one of the most common congenital cardiac malformations in dogs. Unfortunately, the long term success rate and survival data following either open heart surgery or catheter based intervention has been disappointing in dogs with severe subaortic stenosis. Medical therapy is currently the only standard recommended treatment option. A cutting balloon dilation catheter has been used successfully for resistant coronary artery and peripheral pulmonary arterial stenoses in humans. This catheter is unique in that it has the ability to cut, or score, the stenotic region prior to balloon dilatation of the stenosis. The use of cutting balloon valvuloplasty combined with high pressure valvuloplasty for dogs with severe subaortic stenosis has recently been reported to be a safe and feasible alternative therapeutic option. The following report describes this technique, outlines the materials required, and provides some 'tips' for successful percutaneous subaortic balloon valvuloplasty.

Intracardiac foreign body in a dog.

A dog that was referred to the University of Florida Veterinary Medical Center was discovered to have a bamboo skewer within the right atrium and right ventricle, traversing the tricuspid valve. The skewer was ingested approximately four months prior to referral and was partially removed via gastrotomy. The presenting complaint at the time of referral included coagulopathy, anemia and leukocytosis. A linear, hyperechoic structure was identified in the right heart during an echocardiogram. The foreign body was suspected to be a portion of the skewer that the patient had previously ingested. Cardiopulmonary bypass was performed and the foreign body was removed successfully. Complications following surgery included the development of tricuspid valve and ventricular wall thrombi, atrial flutter and amiodarone toxicity. Many indications have been described in the veterinary literature for cardiopulmonary bypass. However, to the best of the authors' knowledge, successful removal of an intracardiac foreign body with cardiopulmonary bypass has not been reported in a veterinary patient. This represents a new indication for cardiopulmonary bypass in veterinary medicine.