Myxomatous Mitral Valve Disease Research Articles

Comparison of St. Thomas II Cardioplegia and Modified Del Nido Cardioplegia in Dogs Undergoing Mitral Valve Surgery

Myocardial protection has become an essential adjunctive procedure in veterinary cardiac surgery. Del Nido cardioplegia is a good alternative to the traditional St. Thomas II (ST) cardioplegia in open heart surgery in humans. This study aims to compare intra- and postoperative results between ST cardioplegia and modified del Nido (mDN) cardioplegia in mitral valve surgery in dogs with myxomatous mitral valve disease (MMVD). This retrospective study was conducted using clinical records of 16 MMVD dogs that underwent either ST or mDN cardioplegia. We measured cardiopulmonary bypass (CPB) time, aortic cross-clamp (ACC) time, total operation time, the number of cardioplegia doses, total amount of cardioplegia, required defibrillations, in-hospital mortality and pre- and one-month postoperative echocardiographic variables. CPB (159.4 ± 16.1 vs. 210.1 ± 34.0 min), ACC (101.4 ± 7.0 vs. 136.0 ± 24.8 min) and total operation time (262.3 ± 13.1 vs. 327.0 ± 45.4 min) were significantly shorter in the mDN group (p < 0.05). The number of cardioplegia doses (3.25 ± 0.4 vs. 6.25 ± 1.2) and total amount of cardioplegia (161.3 ± 51.5 vs. 405.0 ± 185.9 mL) in the mDN group were also significantly smaller than the ST group (p < 0.05). No difference was observed in the requirement of defibrillation, in-hospital mortality and pre- and postoperative echocardiographic variables. The utilization of mDN cardioplegia was associated with shorter operative time in mitral valve surgery in dogs.

Frontal QRST Angle as a Marker of Arrhythmogenesis and Disease Progression in Dogs with Myxomatous Mitral Valve Disease

Frontal QRST Angle as a Marker of Arrhythmogenesis and Disease Progression in Dogs with Myxomatous Mitral Valve Disease

Pulmonary-vein-to-pulmonary-artery ratio can be utilized to evaluate myxomatous mitral valve disease progression in dogs.

To evaluate the diagnostic value of pulmonary-vein-to-pulmonary-artery ratio (PV:PA) in dogs with myxomatous mitral valve degeneration (MMVD), classified according to the American College of Veterinary Internal Medicine (ACVIM) consensus guidelines. 80 client-owned dogs with either MMVD (n = 65) or no cardiovascular disease (control group; n = 15) between August 5, 2020, and July 19, 2023. This is a retrospective study. Dogs with MMVD were classified according to ACVIM consensus guidelines. Echocardiograms, thoracic radiographs, and other measurements needed in this study were reviewed in all dogs. Spearman correlation was used to determine the correlation between the PV:PA and the following variables: vertebral heart size, vertebral left atrial size, left-atrium-to-aorta ratio, normalized left ventricular internal diameter, and peak transmitral early diastolic velocity. Receiver operating characteristic (ROC) curve analysis was used to evaluate the value of PV:PA in distinguishing between stages B1 and B2 and stages B2 and C. All conventional indices showed correlations with PV:PA. The area under the ROC curve (AUC) for stages B1 and B2 was 0.83, and the cutoff value for differentiating stage B2 was 1.52. The AUC for stages B2 and C was 0.81, and the cutoff value for differentiating stage C was 2.09. PV:PA was significantly different between control and the stage B1 group, stage B1 and B2 group, and stage B2 and C group. PV:PA can be an index that can be used in evaluating MMVD dogs.

Blood cardioplegia reduces intraoperative ventricular fibrillation and transfusion requirements compared to crystalloid cardioplegia in canine mitral valve repair.

Cardioplegic solutions are indispensable for open-heart surgeries, including mitral valve repair (MVR), a potentially curative treatment for myxomatous mitral valve disease in dogs. However, procedural methodologies are not fully established, and complications are yet to be comprehensively understood. Cardioplegic solutions contain various substances to protect the myocardium under temporal cardiac arrest. Nevertheless, ventricular fibrillation (VF) occurs as a common complication after releasing the crossclamp. Based on these backgrounds, the search for optimal cardioplegic solutions in dogs undergoing MVR is an urgent issue. This study aims to evaluate the occurrence of VF in dogs treated with blood cardioplegia (BCP) versus crystalloid cardioplegia (CCP) during MVR. A total of 251 client-owned dogs who underwent MVR from November 2015 to November 2017 were included. We retrospectively assessed the relationship between VF and type of cardioplegia (CCP or BCP) based on surgical records, including VF incidence, transfusion use, crossclamp time, and echocardiographic measurements. Logistic regression analysis showed that the CCP group was associated with the occurrence of VF (OR, 2.378; CI, 1.133-4.992; P = .022). In addition, the CCP group was associated with transfusion use (OR, 2.586; CI, 1.232-5.428, P = .022). There was no difference between the groups for the pre- and postoperative echocardiographic measurements. The BCP group had a lower incidence of VF and less transfusion use than the CCP group. This finding indicates that BCP may be a superior cardioplegic technique for MVR in dogs.

Myxomatous mitral valve disease and associated pulmonary hypertension might increase serum angiopoietin-2 in dogs.

To evaluate the relationships between the severity of myxomatous mitral valve disease (MMVD) and pulmonary hypertension (PH) and serum angiopoietin (Ang)-1 and Ang-2 concentrations in dogs with MMVD. 74 dogs (control, n = 12; MMVD, n = 62) were included. Serum Ang-1 and Ang-2 concentrations were estimated using the canine-specific ELISA kit. The concentrations were compared between dogs with MMVD and healthy dogs, and they were analyzed according to the severity of MMVD and PH. The median serum Ang-1 concentration did not differ among the study groups. The median serum Ang-2 concentration was higher in dogs with stage B2 MMVD (P = .041) and acute congestive heart failure (P = .002) than in control dogs. In addition, the median serum Ang-2 concentration was higher in MMVD dogs with PH than in those without PH (P = .031). Serum Ang-2 concentration was correlated with vertebral heart score (rs = 0.36, P = .004) and vertebral left atrial score (r = 0.50, P < .001) in dogs with MMVD, and correlated with vertebral heart score (r = 0.63, P = .01), maximum E wave amplitude of the diastolic transmitral flow (rs = 0.61, P = .018), ejection fraction (rs = -0.77, P < .001) and fractional shortening (rs = -0.56, P = .032) in dogs with acute congestive heart failure. Circulating Ang-2 levels increase in dogs with the severity of MMVD and the presence of PH.

Assessment of radiographic left atrial dimension and C-reactive protein in dogs with myxomatous mitral valve disease

Assessment of radiographic left atrial dimension and C-reactive protein in dogs with myxomatous mitral valve disease

Utility of focused cardiac ultrasonography training in veterinary students to differentiate stages of subclinical myxomatous mitral valve disease in dogs.

Differentiation of the subclinical phases of myxomatous mitral valve disease (MMVD) in dogs relies heavily on echocardiography. Focused cardiac ultrasonography (FCU) is a point-of-care technique that can assess heart size. Veterinary students trained in FCU can differentiate dogs with subclinical MMVD based on left ventricular (LV) and left atrial (LA) dimensions. Forty-eight dogs with subclinical MMVD. Veterinary students were trained to measure LV dimension and LA-to-aortic root dimension ratio (LA : Ao) using FCU. Dogs were categorized into 2 cohorts based on whether or not the LV normalized internal diastolic dimension was ≥1.7 and LA : Ao was ≥1.6. Agreement between FCU and echocardiographic studies performed by cardiologists was evaluated. One-hundred and forty-six FCU examinations were performed by 58 veterinary students on 48 dogs. Overall agreement between students and cardiologists was moderate (Fleiss' kappa, 0.54; 95% confidence interval [CI], 0.39-0.69; P < .001). Percentage accuracy in observations with heart dimensions less than the cutoffs (86/89, 97%) was significantly higher than in observations in with larger hearts (31/57, 54%; P < .001). Agreement increased from moderate to good as heart sizes became more extreme. Degree of confidence by students in performing FCU was significantly higher at the end vs start of the study. Categorization of dogs with subclinical MMVD by veterinary students using FCU was associated with moderate to good agreement with echocardiography. Focused cardiac ultrasonography is a point-of-care method that can help assess clinical stage in dogs with subclinical MMVD.

Proteomic analysis of the serum in dogs with pulmonary hypertension secondary to myxomatous mitral valve disease: the preliminary study.

Pulmonary hypertension (PH) is a common complication in dogs with myxomatous mitral valve disease (MMVD), characterized by elevated blood pressure in pulmonary artery. Echocardiography is a reliable technique for PH diagnosis in veterinary medicine. However, it is limited to use as an early detection method. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) has found extensive application in the discovery of serum protein biomarkers for various diseases. The objective of this study was to identify serum proteins in healthy control dogs and MMVD dogs both with and without PH using LC-MS/MS. In this research, a total of 81 small-breed dogs participated, and they were categorized into three groups: the control (n = 28), MMVD (n = 24) and MMVD+PH (n = 29) groups. Serum samples were collected and analyzed by LC-MS/MS. Differentially expressed proteins were identified, and the upregulated and downregulated proteins in MMVD+PH group including Myomesin 1 (MYOM1) and Histone deacetylase 7 (HDAC7), Pleckstrin homology domain containing M3 (PLEKHM3), Diacylglycerol lipase alpha (DAGLA) and Tubulin tyrosine ligase like 6 (TTLL6) were selected as proteins of interest in MMVD dogs with PH. Different types of proteins have been identified in healthy dogs and MMVD dogs with and without PH. Additional studies are needed to investigate the potential of these proteins as biomarkers for PH in dogs with MMVD.

Myxomatous Mitral Valve Disease in Large Breed Dogs: Survival Characteristics and Prognostic Variables.

Myxomatous mitral valve disease (MMVD) is the most common acquired heart disease in dogs and its occurrence in small-and medium-sized dogs has been extensively investigated. MMVD has been described in large breed dogs as well, but substantial knowledge gaps remain. The aim of this study was to provide characteristics, survival times, and prognostic variables in large breed dogs with MMVD. Medical records of dogs diagnosed with MMVD, between 2012 and 2021, were retrospectively reviewed and 202 dogs were analyzed. Median survival time (MST) for all-cause mortality was 800 days for stage B1 dogs, 274 days for stage B2 dogs, and 184 days for stage C dogs. The MST for cardiac-related death for B1 dogs could not be calculated (because survival was greater than 50% at the last timepoint) and for stage B2 and C dogs the MST were 484 and 252 days, respectively. These findings suggest that the frequency of cardiac-related death is low in large breed dogs with stage B1 MMVD. In addition, increased left atrial and ventricular size, evidence of systolic dysfunction, a thrilling murmur, and increased early trans-mitral peak velocity are predictors of cardiac-related death. Data also suggest that the risk of a negative outcome increases profoundly when large breed dogs advance from ACVIM stage B1 into stage B2 or C.

Pulmonary Hypertension Secondary to Myxomatous Mitral Valve Disease in Dogs: Current Insights into the Histological Manifestation and Its Determining Factors

Pulmonary venous hypertension (PVH) is caused by deteriorating left ventricular function. The most common cause of PVH in dogs is myxomatous mitral valve degeneration (MMVD). It causes left ventricular volume overload and an increase in left atrial and pulmonary venous pressure (PVH), which leads to pulmonary vascular wall remodeling and contributes to the perpetuation and worsening of PVH. Pulmonary vascular wall remodeling is also characteristic of pulmonary arterial hypertension (PAH). However, the changes in PVH arise secondary to heart failure and vascular remodeling progresses as the disease progresses. On the other hand, PAH is a primary disease that can be triggered, for example, by the use of certain drugs. Similar structural changes may suggest the influence of similar pathophysiological mechanisms or the intermediation of similar mediators. Therefore, this article discusses recent and hitherto uncommented findings elucidating the pathophysiology of the processes and influences on the pattern of histological changes observed in pulmonary hypertension secondary to degenerative mitral valve disease. In particular, we focus on the activity of factors such as endothelin, serotonin, and nitric oxide, which are involved in pulmonary vascular wall remodeling in both PVH and PAH.

Machine Learning Techniques for Canine Myxomatous Mitral Valve Disease Classification: Integrating Anamnesis, Quality of Life Survey, and Physical Examination.

Myxomatous mitral valve disease (MMVD) is a prevalent canine cardiac disease typically diagnosed and classified using echocardiography. However, accessibility to this technique can be limited in first-opinion clinics. This study aimed to determine if machine learning techniques can classify MMVD according to the ACVIM classification (B1, B2, C, and D) through a structured anamnesis, quality of life survey, and physical examination. This report encompassed 23 veterinary hospitals and assessed 1011 dogs for MMVD using the FETCH-Q quality of life survey, clinical history, physical examination, and basic echocardiography. Employing a classification tree and a random forest analysis, the complex model accurately identified 96.9% of control group dogs, 49.8% of B1, 62.2% of B2, 77.2% of C, and 7.7% of D cases. To enhance clinical utility, a simplified model grouping B1 and B2 and C and D into categories B and CD improved accuracy rates to 90.8% for stage B, 73.4% for stages CD, and 93.8% for the control group. In conclusion, the current machine-learning technique was able to stage healthy dogs and dogs with MMVD classified into stages B and CD in the majority of dogs using quality of life surveys, medical history, and physical examinations. However, the technique faces difficulties differentiating between stages B1 and B2 and determining between advanced stages of the disease.

Association between echocardiographic indexes and urinary Neutrophil Gelatinase-Associated Lipocalin (uNGAL) in dogs with myxomatous mitral valve disease

Neutrophil gelatinase-associated lipocalin (NGAL) is a biomarker of tubular damage, and its elevation has been described in human and canine cardiorenal syndrome.The aim was to evaluate the association between echocardiographic indexes and urine NGAL (uNGAL) and uNGAL normalized to urine creatinine (uNGALC) in dogs with MMVD.This is a multicentric prospective cross-sectional study. A total of 77 dogs with MMVD at different ACVIM stages were included. All dogs underwent echocardiography, serum chemistry, and urinalysis. Echocardiographic data analyzed were shortening fraction (SF), left ventricular diastolic (LVIDDn) and systolic (LVIDSn) diameters normalized for body weight, left atrium to aortic root ratio (LA/Ao), maximal (LAVMax) and minimal (LAVMin) left atrial volumes, LA stroke volume (LASV), early diastolic mitral peak velocity (EVmax), EVmax to tissue Doppler E' wave (E/E'), aortic (VTIAo) and mitralic (VTIMit) velocity time integrals and their ratio (VTIMit/VTIAo), and tricuspid regurgitation velocity (TRVmax).In the univariate analysis LASV, TRVmax, LAVMax, LVIDDn, and VTIMit/VTIAo were independent predictors of increased uNGAL and uNGALC; however, only LASV [(OR: 1.96, 95% CI: 1.16 to 3.31) P = 0.01 for NGAL, and (OR: 2.79, 95% CI: 1.50 to 5.17) P < 0.001 for NGALC] and TRVmax [(OR: 1.73, 95% CI: 1.20–2.51) P = 0.002 for NGAL, and (OR: 1.50, 95% CI: 10.07–2.10) P = 0.015 for NGALC] remained statistically significant in the multivariable analysis.Based on our results, LASV and TRVmax are associated with increased uNGAL and uNGALC. These parameters might detect dogs with MMVD at higher risk of developing kidney damage.

Relationship between syringomyelia and myxomatous mitral valve disease in Cavalier King Charles spaniels.

Syringomyelia (SM) and myxomatous mitral valve disease (MMVD) are highly prevalent in Cavalier King Charles spaniels (CKCS). Cardiac status in CKCS with and without SM is currently unknown. To investigate the association between SM and MMVD severity in CKCS and CKCS with SM with and without clinical signs of SM. Fifty-five CKCS: 40 with SM (22 symptomatic and 18 asymptomatic) and 15 without SM. A combined retrospective and prospective study. MRI and echocardiography were used to diagnose SM and MMVD, respectively. The association between SM and MMVD severity (left ventricle internal diameter in diastole normalized to bodyweight [LVIDDN] and left atrium to aortic ratio [LA/Ao]) were tested using multivariable linear regression analysis adjusting for sex and age. Overall, no significant difference in LVIDDN and LA/Ao was found between CKCS with or without SM. However, CKCS with symptomatic SM had significantly smaller LVIDDN (1.45 [1.30-1.50]) (median [IQR]) and LA/Ao (1.20 [1.10-1.28]) compared to CKCS with asymptomatic SM (1.60 [1.50-1.90] and 1.40 [1.20-1.75]) as well as CKCS without SM (0.24 [0.03-0.45] and 0.30 [0.05-0.56]) (all P values <.03). An association between MMVD and SM was not confirmed in this cohort of CKCS, indicating that MMVD and SM do not co-segregate. However, CKCS with symptomatic SM had smaller left ventricle and atrial size compared to CKCS with asymptomatic SM and CKCS without SM.

Hypoglycemia after Mitral Valve Repair in Dogs.

Hypoglycemia has not been previously reported as a postoperative complication of mitral valve repair (MVR) in dogs; however, the authors have encountered cases of hypoglycemia after MVR. This study aimed to determine the incidence of hypoglycemia in dogs after MVR and investigate its causes. Blood glucose levels were measured at multiple timepoints in dogs undergoing MVR. Simultaneously, insulin and glucagon blood concentrations in dogs with hypoglycemia preoperatively and postoperatively were compared to verify the physiological responses to hypoglycemia. Furthermore, risk factors for hypoglycemia, using variables selected based on the characteristics of MVR and dogs undergoing MVR, were examined prospectively. The incidence of hypoglycemia after MVR was 14.2%, and plasma glucagon concentrations increased in these dogs (mean: 260 pg/mL and 644 pg/mL pre- and postoperatively, p < 0.001), whereas serum insulin concentrations decreased (median: 0.50 ng/mL and 0.29 ng/mL pre- and postoperatively, p = 0.002). Therefore, hyperinsulinemia or hypoglucagonemia is unlikely to be the cause of postoperative hypoglycemia. The identified risk factors for hypoglycemia included low body weight and asymptomatic myxomatous mitral valve disease. Monitoring blood glucose levels after MVR should be included in the standard hospitalization plan to prevent hypoglycemic emergencies in dogs.

Risk Factors for Atrial Fibrillation in the Dog: A Systematic Review.

Different risk factors for atrial fibrillation (AF) development have been identified in numerous studies on humans, but this information is less clearly available on the dog. The aim of this systematic review is to determine the risk factors for AF in the dog. Following the PRISMA 2020 guidelines, we conducted a comprehensive search using the Web of Science and Scopus databases for articles reporting on cases of spontaneously occurring AF in dogs. The level of evidence was assessed using the Evidence Quality Grading System of the National Institute of Health. One thousand forty-three studies were initially identified, and twenty of them were included in this systematic review involving 2,359,275 dogs, of which 4807 showed spontaneously occurring AF. Genetics, for the Irish Wolfhound, increased body weight, and left atrial enlargement were the main risk factors for the development of AF in dogs with different cardiac diseases, particularly myxomatous mitral valve disease (MMVD) and dilated cardiomyopathy (DCM). However, some differences were found between these two cardiac diseases regarding additional risk factors. In particular, the presence of congestive heart failure and echocardiographic evidence of increased left atrial pressure or the presence of right atrial enlargement emerged as risk factors in dogs with MMVD or DCM, respectively. Furthermore, significant differences in risk factors were observed between dogs and humans. In particular, advanced age and male sex are not reliable indicators of an increased risk of AF in dogs.

Effects of mitral valve repair on valvular geometry and hemodynamics in dogs with myxomatous mitral valve disease.

To investigate the effects of mitral valve repair on the geometry of the mitral valve complex, hemodynamics, and cardiac function of dogs with myxomatous mitral valve disease (MMVD). Retrospective cohort study. Dogs (n = 77) with stage C MMVD undergoing mitral valve repair under cardiopulmonary bypass. Mitral valve geometry and cardiac function were assessed using echocardiography preoperatively, 1 week postoperatively and 3 months postoperatively. The coaptation length (0 [0-0] vs. 7 [6-8.5] mm, p < .001) and forward stroke volume index (1.5 ± 0.4 vs. 2.3 ± 0.6 mL/kg, p < .001) were higher at 3-months postoperatively than preoperatively, whereas the vertebral heart score (12.3 ± 1.2 vs. 10.8 ± 0.8 V, p < .001), left atrial-to-aortic ratio (2.2 ± 0.7 vs. 1.2 ± 0.3, p < .001), peak velocity of early diastolic transmitral flow (144 ± 34 vs. 91 ± 18 cm/s, p < .001), and regurgitant volume index (11.3 [8.2-14.0] vs. 1.6 [0.95-2.35] mL/kg, p < .001) were lower. Postoperatively, mitral valve geometry was completely changed within 1 week, whereas changes in vertebral heart score lasted for 3 months. Mitral valve repair changed valvular geometry and improved hemodynamics as assessed by follow-up echocardiography. This study acts as reference for surgeons and cardiologists considering or evaluating the effects of mitral valve repair in dogs and provides useful data for the enhancement of relevant surgical techniques and the selection of relevant pre- and postoperative observations.

Echocardiographic values and prevalence of cardiac abnormalities in clinically healthy adult Borzoi dogs.

To develop breed-specific echocardiographic values for normal Borzoi and to report the prevalence of structural cardiac abnormalities. 146 clinically healthy, adult Borzoi dogs. Cardiac auscultation and standard echocardiograms were performed. Longitudinal follow-up was described in a subset of dogs (n = 25). Most Borzoi were structurally normal (119/146, 81.5%), with breed-specific echocardiographic values generated independently for each sex, as females weighed significantly less than males (30.4 ± 3.8 kg vs 38.3 ± 4.1 kg, respectively; P < .001), and a significant impact of sex was found on most measurements. Physiologic heart murmurs were identified in 64/119 (53.8%) normal dogs. Thirty-six (30.2%) structurally normal dogs had trace or mild mitral regurgitation, and 43 (36.1%) had trace or mild tricuspid regurgitation. Structural cardiac disease was identified in 21 dogs (14.4%), including 9 dogs (6.2%) with dilated cardiomyopathy (DCM), 9 dogs (6.2%) with stage B1 myxomatous mitral valve disease (MMVD), and 3 (2.1%) dogs with congenital abnormalities. Seven dogs (4.8%) had equivocal abnormalities. During follow-up, new dogs were diagnosed with occult DCM (n = 3), equivocal DCM (1), and stage B1 MMVD (2). Two dogs originally diagnosed with DCM (1 occult and 1 equivocal) normalized after diet change. Borzoi dogs commonly have physiologic heart murmurs and mild atrioventricular valve regurgitation. Both DCM and MMVD were identified at similar frequencies in healthy Borzoi, although dogs with MMVD all had normal heart sizes. Echocardiographic screening for DCM in Borzoi should be considered, with breed-specific echocardiographic values now available for improved diagnostic confidence.

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Dogs With Various Degrees of Myxomatous Mitral Valve Disease

Neutrophil-to-Lymphocyte Ratio and Platelet-to-Lymphocyte Ratio in Dogs With Various Degrees of Myxomatous Mitral Valve Disease

Determination of radiographic vertebral heart score and vertebral left atrial size cutoffs based on echocardiographic left atrial size in dogs with myxomatous mitral valve disease.

Progression of myxomatous mitral valve disease (MMVD) in dogs is a common cause of left atrial enlargement. Recently, a classification of left atrial (LA) size based on echocardiographic measurement has been proposed. This study aims to determine the radiographic LA size by reporting the cutoff values of VHS and VLAS for different groups of echocardiographic-measured LA size in dogs with MMVD. This retrospective analytical cross-sectional study included dogs diagnosed with MMVD grouped based on the echocardiographic LA size into normal (LA/Ao<1.6), mild (1.6-1.89), moderate (1.9-2.2), and severe enlargement (>2.2) and were compared with ACVIM classification. VHS and VLAS were measured on the right lateral radiograph for each dog and cutoff values were calculated. One hundred and three dogs with MMVD were included in the study. A very strong positive correlation was observed between LA/Ao ratio and VHS (rs , 0.823, P<.01) or VLAS (rs , 0.834, P<.01). For VHS, a cutoff of 10.7 v, 11 v, and 11.5 v were established for echocardiographic LA thresholds of 1.6, 1.9, and 2.2 with a sensitivity of 79%, 92%, and 90% and a specificity of 97%, 90.7%, and 78.1%, respectively. For VLAS, a cutoff of 2.5 v, 2.7 v, and 2.9 v were established for echocardiographic LA cutoffs of 1.6, 1.9, and 2.2 with a sensitivity of 73%, 80%, and 83.3% and a specificity of 94%, 92%, and 86.3%, respectively. The results of this study may facilitate clinical decisions based on radiographic examination in dogs with myxomatous mitral valve disease.

Improved owner quality of life following surgical repair of canine myxomatous mitral valve disease.

To determine quality-of-life changes in owners of dogs undergoing mitral valve repair for myxomatous mitral valve disease, up to 12 months postoperatively. Owners of 26 dogs undergoing mitral valve repair at a single UK veterinary referral hospital. Dogs underwent mitral valve repair under cardiopulmonary bypass as previously described. Owner quality of life was assessed by self-completion of a previously validated questionnaire preoperatively and at 1, 3, 6, and 12 months postoperatively. There was a statistically significant improvement in quality-of-life scores from preoperatively up to 3 months postoperatively and a statistically significant improvement in individual question scores up to 6 months postoperatively. Results suggested that owner quality of life is significantly improved following surgical repair of their pet's myxomatous mitral valve disease, and this improvement continues beyond the immediate postoperative period. These results may be useful when counseling owners of surgical candidates and is another useful outcome measure.