Transvenous correction of patent ductus arteriosus in two toy-breed dogs with the Amplatzer™ Vascular Plug 4.

Two Pomeranian dogs referred for interventional correction of a left-to-right shunting patent ductus arteriosus (PDA) had inadequate femoral arterial access for any occlusion device other than micro coils. The decision was made to attempt correction of the PDA using the Amplatzer™ Vascular Plug 4 (AVP4) from a femoral venous approach. An AVP4 was successfully deployed in each dog with complete occlusion noted within 5 min. Complete occlusion was persistent at 24 h after the procedure, while both dogs were subclinical, had no residual ductal flow, and complete or near complete reverse cardiac remodeling at subsequent visits. This report demonstrates the feasibility of PDA occlusion with the AVP4 from the femoral venous approach in small dogs where femoral arterial access is inadequate for other occlusion devices.

Transarterial correction of patent ductus arteriosus in small dogs with the Amplatz™ Vascular Plug 4: A pilot study.

OBJECTIVES: Determine if the Amplatz™ Vascular Plug 4 (AVP4) can be used to occlude left-to-right shunting patent ductus arteriosus (PDA) in dogs with inadequate arterial vascular access for the Amplatz Canine Duct Occluder (ACDO). ANIMALS: Six adolescent dogs with PDA whose femoral artery was too small for insertion of a 4 Fr vascular access sheath. MATERIALS AND METHODS: Standard femoral arterial vascular access and a 4 Fr diagnostic catheter were used to deploy an appropriately sized AVP4 into the PDA of each dog. Successful occlusion was defined as no residual ductal flow and determined by color Doppler echocardiography and angiography. RESULTS: The AVP4 was successfully deployed, and complete occlusion of the PDA was achieved in all dogs. There were no complications encountered in any of the dogs. CONCLUSIONS: The AVP4 is a viable option for the correction of PDA in dogs with inadequate arterial vascular access for the ACDO and should be considered as one of the options available for PDA correction in this challenging animal population.

Identification of multilevel right-to-left shunting in a dog using nuclear scintigraphy imaging.

A 27-month-old male neutered French bulldog that was originally diagnosed with tricuspid valve dysplasia and a bidirectional shunting patent foramen ovale was evaluated for progressive polycythemia and exertional cyanosis. There was a high clinical suspicion for a right-to-left shunting patent ductus arteriosus, but given the presence of agitated saline within the left atrium, left ventricle, ascending aorta, and abdominal aorta from the previously diagnosed bidirectional shunting patent foramen ovale, a definitive diagnosis could not be made. The use of dynamic and static nuclear scintigraphy imaging using technetium-labeled macroaggregated albumin (99mTc-MAA) allowed a definitive diagnosis to be made in this animal with multilevel right-to-left shunting as well as quantifying the severity of the right-to-left shunt in a minimally invasive and cost-effective manner.

Use of n-butyl cyanoacrylate to reduce left to right shunting of an abdominal arteriovenous malformation in a dog.

A 9-month old castrated male Labradoodle presented to the cardiology service at Purdue University for evaluation of a low-grade murmur. Physical examination, thoracic radiography, and echocardiography were strongly supportive of an extracardiac left-to-right shunt. Subsequent evaluation with nuclear scintigraphy and computed tomography angiography revealed a large, complex arteriovenous malformation within the cranial abdomen. Staged interventional attenuation of the shunt was performed using n-butyl cyanoacrylate that resulted in a reduction in echocardiographic and nuclear scintigraphy derived shunt estimation.

Multicenter evaluation of plasma N-terminal probrain natriuretic peptide (NT-pro BNP) as a biochemical screening test for asymptomatic (occult) cardiomyopathy in cats.

BACKGROUND: B-type natriuretic peptide concentrations reliably distinguish between cardiac and respiratory causes of dyspnea, but its utility to detect asymptomatic cats with occult cardiomyopathy (OCM) is unresolved. HYPOTHESIS/OBJECTIVES: Determine whether plasma N terminal probrain natriuretic peptide (NT-proBNP) concentration can discriminate asymptomatic cats with OCM from normal cats, and whether NT-proBNP concentration correlates with clinical, biochemical, and echocardiographic parameters. ANIMALS: One hundred and fourteen normal, healthy cats; 113 OCM cats. METHODS: Prospective, multicenter, case-controlled study. NT-proBNP was prospectively measured and cardiac status was determined from history, physical examination, and M-mode/2D/Doppler echocardiography. Optimal cut-off values were derived using receiver operating characteristic (ROC) curve analysis. RESULTS: NT-proBNP was higher (median, interquartile range [25th and 75th percentiles]) in (1) OCM (186 pmol/L; 79, 478 pmol/L) versus normal (24 pmol/L; 24, 32 pmol/L) (P < .001); and (2) hypertrophic obstructive cardiomyopathy (396 pmol/L; 205, 685 pmol/L) versus hypertrophic cardiomyopathy (112 pmol/L; 48, 318 pmol/L) (P < .001). In OCM, NT-proBNP correlated (1) positively with LVPWd (ρ = 0.23; P = .01), LA/Ao ratio (ρ = 0.31; P < .001), LVs (ρ = 0.33; P < .001), and troponin-I (ρ = 0.64; P < .001), and (2) negatively with %FS (ρ = -0.27; P = .004). Area under ROC curve was 0.92; >46 pmol/L cut-off distinguished normal from OCM (91.2% specificity, 85.8% sensitivity); >99 pmol/L cut-off was 100% specific, 70.8% sensitive. CONCLUSIONS AND CLINICAL IMPORTANCE: Plasma NT-proBNP concentration reliably discriminated normal from OCM cats, and was associated with several echocardiographic markers of disease severity. Further studies are needed to assess test performance in unselected, general feline populations, and evaluate relationships between NT-proBNP concentrations and disease progression.

Perceptions of quality of life and priorities of owners of cats with heart disease.

BACKGROUND: Owners' perceptions and priorities regarding quality of life (QoL) are important considerations given the unknown efficacy of many commonly administered medications, stress of hospital visits, difficulties providing home care, and personal choices including euthanasia. OBJECTIVE: To describe the relative importance of quality versus quantity of life to owners of cats with heart disease. ANIMALS: Two hundred and thirty-nine cats with heart disease. METHODS: Prospective questionnaire-based clinical study. Cat owners completed a questionnaire to identify important parameters when assessing their cat's QoL, the relative importance of quality versus quantity of life, and willingness to trade survival time for QoL. Variables associated with these parameters were evaluated with multivariate analyses. RESULTS: Appetite, owner interaction, sleep patterns, and litterbox habits were deemed important to QoL. Concern over pet suffering was significantly greater than concern over life expectancy. Ninety-three percent of owners were willing to trade survival time for good QoL; 57% of these were willing to trade up to 6 months. On multivariate analysis, the only factor significantly (P=.002) associated with willingness to trade 6 months was study site. Owner concern regarding stress of administering medications at home increased with number and frequency of medications. CONCLUSIONS AND CLINICAL RELEVANCE: These results indicated that QoL is more important to owners of cats with heart disease than longevity. The various priorities and concerns of cat owners should be taken into account in order to provide optimal care.

Intravascular occlusion for the correction of extrahepatic portosystemic shunts in dogs.

BACKGROUND: Congential extrahepatic portosystemic shunts (EHPSS) are common in dogs. An effective minimally invasive technique for correction of EHPSS could result in reduced morbidity, reduced costs, and reduced hospitalization times. HYPOTHESIS: Use of an intravascular occlusion device can effectively and safely result in acute complete occlusion of EHPSS in dogs. ANIMALS: Seven dogs with naturally occurring EHPSS that presented to the Purdue University Veterinary Teaching Hospital. METHODS: Prospective, clinical trial. The 7 dogs were consecutively enrolled over a 2-year period. Results of serum biochemistry, total serum bile acids, fasting plasma ammonia, abdominal radiography, and ultrasonography suggested the diagnosis of portosystemic shunts in all dogs. Definitive diagnosis of EHPSS was achieved with cranial mesenteric arterial portography and acute occlusion was attempted by the deployment of the Amplatzer vascular plug (AVP). RESULTS: EHPSS were identified in all dogs consisting of 5 portocaval and 2 portoazygous variants; 1/7 dogs (14%) were intolerant to temporary complete occlusion of the EHPSS. Of the remaining 6 dogs, 5 (83%) had complete occlusion of the EHPSS by the AVP. There were no complications and resolution of abnormal clinical signs and laboratory values was achieved in 4/5 (80%) dogs with complete occlusion. CONCLUSIONS AND CLINICAL IMPORTANCE: Intravascular correction of EHPSS by the AVP is a viable option to surgical correction while larger studies will be required to determine the clinical applicability of this procedure in the broader portosystemic shunt population.

Antithrombotic effect of enoxaparin in clinically healthy cats: a venous stasis model.

BACKGROUND: Systemic arterial thromboembolic events are a serious complication of cardiac disease in cats. OBJECTIVES: To determine if enoxaparin induces an antithrombotic effect in cats at a dosage of 1 mg/kg SC q12h and if this antithrombotic effect is predicted by anti-Xa activity. ANIMALS: Fourteen clinically healthy cats were divided into 3 groups: control (4 cats), treated and assessed at 4 hours (5 cats), and treated and assessed at 12 hours (5 cats). METHODS: A venous stasis model was used and the extent of thrombus formation estimated by measuring thrombus weight and accretion of 125I-fibrinogen. Plasma anti-Xa activity was measured in treated cats. RESULTS: There was a significant reduction in thrombus formation in the 4 h group compared with control (median weight, 0.000 versus 0.565mg/mm, P < .01; median % 125I-fibrinogen accretion, 0.0 versus 42.0%, P < .01). There was a reduction in thrombus formation in the 12 h group (median weight, 0.006 mg/mm, P = .09; median % 125I-fibrinogen accretion, 3.83%, P = .09) but this reduction was not significant. The median percent thrombus inhibition for treated cats was 100.0% at 4 hours and 91.4% at 12 hours. Plasma anti-Xa activity was not significantly correlated with thrombus formation. CONCLUSIONS AND CLINICAL IMPORTANCE: This pilot study demonstrates that enoxaparin, when administered at a dosage of 1 mg/kg SC q12h, produces an antithrombotic effect in a venous statsis model in clinically healthy cats. Furthermore, this study demonstrates that anti-Xa activity is a poor predictor of enoxaparin's antithrombotic effect.

Paraneoplastic thrombocytosis-induced systemic thromboembolism in a cat.

A six-year-old cat presented with clinical signs consistent with distal aortic thromboembolism while clinical signs of cardiovascular disease were absent. Diagnostics, including thoracic radiographs, electrocardiography, and echocardiography revealed no cardiovascular anomalies. Thoracic radiographs revealed multifocal pulmonary lesions consistent with neoplasia. Complete blood cell count demonstrated a marked thrombocytosis, leukopenia, and neutropenia. Histopathology of the pulmonary lesions confirmed multiple bronchoalveolar carcinomas. Myelodysplasia with megakaryocytic hyperplasia and ineffective myelopoiesis was noted on bone-marrow histopathology from multiple sites. The absence of other causes suggested a paraneoplastic thrombocytosis. The diagnosis of paraneoplastic thrombocytosis-induced thromboembolism was made due to the lack of underlying cardiac disease and the presence of a marked thrombocytosis. The presence of thrombocytosis and thromboembolism associated with neoplasia is discussed.

Hypoxemia during outpatient gastrointestinal endoscopy: the effects of sedation and supplemental oxygen.

STUDY OBJECTIVES: To compare the effects on oxygen saturation as measured by pulse oximetry (SpO2) and ECG changes of endoscopy alone, sedation followed by endoscopy, and sedation followed by endoscopy with supplemental oxygen (O2) during upper gastrointestinal (GI) endoscopy. STUDY DESIGN: Randomized trial. SETTING: Outpatient gastroenterology clinic at a university medical center. PATIENTS: 58 healthy patients scheduled for outpatient upper GI endoscopy, with no clinical evidence of respiratory disease. INTERVENTIONS: Patients were randomly allocated to three groups: Group 1 received no benzodiazepines before endoscopy and breathed room air throughout (n = 18), Group 2 received midazolam intravenously (i.v.) before endoscopy and breathed room air throughout (n = 20), and Group 3 received i.v. midazolam and 2 L/min O2 through nasal cannulae during endoscopy (Group 3; n = 20). MEASUREMENTS AND MAIN RESULTS: Data collection, which included heart rate, cardiac rhythm, and SpO2 were recorded at seven intervals: baseline, topical anesthesia of the oropharynx, mouth gag insertion, endoscope insertion, biopsy, endoscope removal, and five minutes postendoscopy. In Group 2, mean SpO2 decreased after midazolam was administered and remained depressed during endoscopy (p < 0.05). After midazolam was given, Group 2 patients differed significantly from patients in Groups 1 and 3 (p < 0.05). CONCLUSIONS: The use of hypnotic doses of benzodiazepines is the primary factor responsible for the reduced oxygenation seen during endoscopy. Neither the presence of the endoscope alone nor the use of midazolam with supplemental O2 caused a decreased oxygenation. This study also suggests that the routine use of benzodiazepines is unnecessary when the endoscopy is of short duration, and the endoscopist employs good topicalization of the oropharynx. In patients who require sedation for endoscopy, O2 administration prevents hypoxemia.