Accuracy of echocardiographically estimated pulmonary artery pressure in dogs with myxomatous mitral valve disease.

INTRODUCTION: Echocardiographically identified pulmonary hypertension is an independent predictor of poor outcome in dogs affected by myxomatous valvular degeneration (MMVD). Systolic pulmonary arterial pressure is routinely estimated based on its relationship with the Doppler-determined velocity of tricuspid regurgitation as defined by the simplified Bernoulli equation (sPAP_D). Experimental studies suggest that the method is imperfect, but its accuracy in dogs with MMVD is not known. ANIMALS: Twenty dogs affected by MMVD that had cardiac remodeling and measurable tricuspid regurgitation. METHODS: A flow-directed thermodilution monitoring catheter was percutaneously placed in the right external jugular vein and advanced to the main pulmonary artery. Pulmonary arterial systolic pressure was recorded (systolic pulmonary arterial pressure obtained by right heart catheterization [sPAP_C]). A second operator contemporaneously acquired tricuspid regurgitant velocity spectra to calculate sPAP_D. Each operator was blinded to the result of the other techniques. RESULTS: Technical difficulties prevented the analysis of catheterization data in two dogs. Eighteen measurement pairs were therefore used for comparison of sPAP_C and sPAP_D through correlation and Bland-Altman analysis. A statistically significant bias between sPAP_C and sPAP_D (mean difference = 0.5 mmHg; confidence interval = -6.5 mmHg, +7.5 mmHg) was not detected. The interval of agreement between the techniques was wide (-27.3 mmHg, +28.2 mmHg). A significant linear association between the two techniques was not identified (r = 0.11, p=0.17). CONCLUSION: Echocardiographically estimated pulmonary artery pressure poorly agrees with sPAP_C measurement in dogs affected by MMVD and cardiac remodeling with or without previously diagnosed congestive heart failure. In these dogs, sPAP_D could under- or over-estimate sPAP_C by more than 20 mmHg, and therefore caution should be used when interpreting sPAP_D.

Mitral valve repair in dogs using an ePTFE chordal implantation device: a pilot study.

OBJECTIVE: Mitral valve (MV) regurgitation due to degenerative MV disease is the leading cause of cardiac death in dogs. We carried out preliminary experiments to determine the feasibility and short-term effects of beating-heart MV repair using an expanded polytetrafluorethylene (ePTFE) chordal implantation device (Harpoon TSD-5) in dogs. ANIMALS: This study involved six healthy purpose-bred Beagles (weight range 8.9-11.4 kg). MATERIAL AND METHODS: Following a mini-thoracotomy performed under general anesthesia, the TSD-5 was used to place 1 or 2 artificial ePTFE cords on the anterior MV leaflet or the posterior MV leaflet via a left-ventricular transapical approach. The procedure was guided and monitored by transesophageal echocardiography. Postoperative antithrombotic treatment consisted of clopidogrel or a combination of clopidogrel and apixaban. Dogs were serially evaluated by transthoracic echocardiography at day 1, 7, 14, 21, and 30. The hearts were then examined for evaluation of tissues reactions and to detect signs of endothelialization. RESULTS: One or two chords were successfully implanted in five dogs. Four dogs completed the 30 days follow-up. One dog died intra-operatively because of aortic perforation. One dog died early post-operatively from a hemorrhagic pleural effusion attributed to overly aggressive antithrombotic treatment. One dog developed a thrombus surrounding both the knot and the synthetic cord. Postmortem exam confirmed secure placement of ePTFE knots in the mitral leaflets in all dogs and the presence of endothelialization of the knots and chords. CONCLUSIONS: These preliminary results demonstrate the feasibility of artificial chordal placement using an ePTFE cordal implantation device in dogs.

Mitral valve morphology assessed by three-dimensional transthoracic echocardiography in healthy dogs and dogs with myxomatous mitral valve disease.

OBJECTIVE: To assess differences in morphology of the mitral valve (MV) between healthy dogs and dogs affected by myxomatous mitral valve disease (MMVD) using real-time transthoracic three-dimensional echocardiography (RT3DE). ANIMALS: Thirty-four were normal dogs and 79 dogs were affected by MMVD. METHODS: Real-time transthoracic three-dimensional echocardiography mitral datasets were digitally recorded and analyzed using dedicated software. The following variables were obtained and compared between healthy dogs and dogs with MMVD at different stages: antero-posterior annulus diameter, anterolateral-posteromedial annulus diameter, commissural diameter, annulus height, annulus circumference, annulus area, anterior leaflet length, anterior leaflet area, posterior leaflet length, posterior leaflet area, non-planar angle, annulus sphericity index, tenting height, tenting area, tenting volume, the ratio of annulus height and commissural diameter. RESULTS: Dogs with MMVD had a more circular MV annulus compared to healthy dogs as demonstrated by an increased annulus sphericity index (p=0.0179). Affected dogs had a less saddle-shaped MV manifest as a decreased annulus height to commissural width ratio (p=0.0004). Tenting height (p<0.0001), area (p<0.0001), and volume (p<0.0001) were less in affected dogs. CONCLUSIONS: Real-time transthoracic three-dimensional echocardiography analysis demonstrated that dogs affected by MMVD had a more circular and less saddle-shaped MV annulus, as well as reduced tenting height area and volume, compared to healthy dogs. Multiple variables differed between dogs at different stages of MMVD. Diagnostic and prognostic utility of these variables, and the significance of these changes in the pathogenesis and natural history of MMVD, require further attention.

Assessment of mitral valve morphology using three-dimensional echocardiography. Feasibility and reference values.

OBJECTIVES: To evaluate the feasibility of real time transthoracic three-dimensional echocardiography (RT3DE) for evaluation of normal canine mitral valves (MVs), and to provide reference values for this technique. ANIMALS: Forty-three cardiologically healthy, not sedated dogs. METHODS: Transthoracic RT3DE mitral datasets were acquired during two consecutive 6-month periods. The datasets were analyzed using commercially available software. An MV model was drawn using a semiautomated procedure and MV variables were obtained and calculated. The ratio between annulus height and commissural diameter was used as an index of the annulus' saddle-shaped non-planarity. After evaluation of associations between measured variables and body size, the datasets were used to generate reference intervals. Coefficients of variation (CVs), variance components, and repeatability coefficients were calculated for the evaluation of intra-observer, inter-observer, and day-to-day variability. RESULTS: Datasets could be analyzed in 34 of 43 (79%) dogs. 68 percent of datasets obtained during the first 6-month period could be analyzed and 90% obtained during the second period could be analyzed. An allometric relationship was identified for most MV variables. The MV annulus appeared elliptical and saddle-shaped. Inter- and intra-observer CVs were less than 20%. Coefficient of variation greater than 20% was calculated for the inter-day variation for some variables. Operator and observer were primarily responsible for the variation of most of the variables. CONCLUSIONS: Evaluation of canine mitral valves by transthoracic RT3DE is feasible. Canine MVs of healthy dogs analyzed using RT3DE are elliptical and saddle-shaped. Reference intervals for the measured MV variables are proposed.

Hospital to home paediatric enteral nutrition--parents need support.

This study assessed the provision of education and support to parents of children on home enteral nutrition (HEN), current dietetic support available and perceived challenges facing parents and carers. From the 39 responses (13%), 29 (83%, n = 35) parents suggested services for HEN need improvement. 29 (74%, n = 39) parents wanted more structured follow up and 22 (56%) would like one person to co-ordinate HEN, education and discharge. 7 parents (18%) reported a need for further education of health care professionals (HCP). Hospital dietitians were the most common HCPs reported to provide support to patients following discharge. Specialist paediatric HEN dietetic services working in a dedicated HEN team, who would provide accurate training and education and liaise with both parents and community care services post discharge should be in place. This would facilitate transfer to community care, reduce hospital re-admissions, outpatient department attendances and costs.

Prion protein (PrP) gene polymorphisms associated with natural scrapie cases and their flock-mates in Ireland.

The PrP genotypes associated with natural scrapie in Ireland were determined and a comparison was made between genotypes found in scrapie-infected sheep and those found in healthy animals from scrapie-infected flocks. Seven PrP genotypes were identified in scrapie-infected animals: VV(136)RR(154)QQ(171),VA(136)RR(154)QQ(171),VA(136)RR(154)QR(171),VA(136)RR(154)QH(171),AA(136)RR(154)QQ(171),AA(136)RR(154)QH(171) and AA(136)RR(154)HH(171). Of 11 scrapie-infected flocks, 15 genotypes were identified in the healthy flock-mates. The genotypes identified in scrapie-affected animals were also all identified in healthy flock-mates. In 9 of the 11 flocks studied, the genotype frequencies among scrapie-infected animals were significantly different from those among healthy flock-mates. The results show that there is a significant risk of developing the clinical signs of scrapie associated with particular PrP genotypes in the Irish sheep population. The association between the V(136)R(154)Q(171) allele and scrapie was evident, as was the association between A(136)R(154)R(171) and resistance to developing the clinical signs of scrapie. The presence of the A(136)H(154)Q(171) allele in the flocks examined resulted in a decreased risk of developing scrapie compared to the presence of the A(136)R(154)Q(171).

Continuing medical education, needs assessment, and program development: theoretical constructs.

Continuing medical education (CME) program development and needs assessment have historically been practiced within the tradition of Ralph Tyler's education model. In light of transformational social, political, economic, and technical forces that demand greater account-ability and responsiveness from physicians, CME units are challenged to transform their cultures and structures from models that deliver education to models that support the facilitation of learning for enhanced competence and performance. This article describes key change forces for physicians and brings program development and needs assessment into focus for the discussion. The impact of change forces on program development and needs assessment are examined, and some techniques to move beyond the traditional approach of felt needs are presented as a way of enabling strategic administrative planning and change management.

Prion protein gene polymorphisms in pedigree sheep in Ireland.

The development of clinical signs of scrapie in sheep has been linked to polymorphisms in the prion protein (PrP) gene. The most important polymorphisms appear to be at codons 136, 154 and 171. The objective of this study was to investigate polymorphisms at these codons in five native (Belclare, Galway, Wicklow Cheviot, Donegal Blackface Mountain and Mayo Blackface Mountain) and five imported (Texel, Bleu du Maine, Rouge de l'Ouest, Vendéen and Charollais) sheep breeds in Ireland. A total of 13 genotypes were found. The percentage of the most resistant genotype AA(136)RR(154)RR(171)varied from 1.8 per cent in the Vendéen breed, 3.1 per cent in Donegal Blackface Mountain, 10.0 per cent in Texel, 11.1 per cent in Wicklow Cheviot, 12.9 per cent in Belclare, 22.0 per cent in Charollais, 25.6 per cent in Mayo Blackface Mountain, 33.3 per cent in Galway, 46.4 per cent in Bleu du Maine to 62.5 per cent in Rouge de l'Ouest. The results indicate that a significant amount of variation exists between the breeds analysed in this study.

Detection of polymorphisms in the prion protein gene in a population of Irish Suffolk sheep.

Natural scrapie is associated with polymorphisms in the prion protein (PrP) gene. In Suffolks, codon 171 is the codon at which most variation is found; RR171 is thought to be associated with resistance to developing the clinical signs of the disease and QQ171 is associated with susceptibility to the disease. The objectives of this study were first to determine the PrP genotypes of Suffolk stock rams in Ireland, and secondly to compare the genotype profiles of ram lambs from flocks where a breeding programme based on the genotype AA136RR154RR171 had been initiated and from flocks where there was no breeding programme based on PrP genotype. Approximately 13 per cent of the stock rams genotyped in the Irish population were genetically susceptible to showing the clinical signs of the disease. However, lambs from farms that had initiated a selective breeding strategy for RR171 over the past year had a larger proportion of RR171 and a smaller proportion of QQ171 than the stock rams or ram lambs from farms not applying a breeding strategy.

Immunohistochemical findings in rheumatoid nodules.

Eighteen nodules from patients with rheumatoid disease were studied histologically and immunohistochemically. A continuum of microscopic changes was observed with varying degrees of fibrinoid necrosis, mononuclear cell infiltration and healing by fibrous scarring. In two cases there was focal evidence of arteritis. Fibrin was plentiful in the necrotic areas of nodules. Small amounts of immunoglobulin were identified in plasma cells and as irregular extracellular deposits in and around areas of necrosis. In a single small vein abnormal IgG was detected. Mononuclear cells surrounding areas of necrosis stained strongly with antisera to ferritin and a cytoplasmic macrophage antigen, stained variably with muramidase (lysozyme) and negatively with alpha-1 antitrypsin antibodies. Perls' stain for ferric iron was almost entirely negative and ultrastructural x-ray microanalysis indicated that the cytoplasm of these cells were entirely free of iron. These findings confirm the chronic inflammatory nature of rheumatoid nodules but provide no support for the view that they originate in areas of vasculitis. A relative lack of cytoplasmic antiprotease along with a strong expression of ferritin appears to be a characteristic feature of macrophages in rheumatoid tissue.