Mitral Valve Disease (mitral + valve_disease)

Distribution by Scientific Domains
Distribution within Medical Sciences

Kinds of Mitral Valve Disease

  • canine degenerative mitral valve disease
  • degenerative mitral valve disease
  • myxomatou mitral valve disease


  • Selected Abstracts


    Left Ventricle and Left Atrium Remodeling after Mitral Valve Replacement in Case of Mixed Mitral Valve Disease of Rheumatic Origin

    JOURNAL OF CARDIAC SURGERY, Issue 4 2010
    n Ender Topal M.D.
    Methods: Thirty consecutive elective patients with MVR for mixed mitral disease of rheumatic origin formed the study group. Of these, 21 (70%) were women and the mean age was 37 years. Transthoracic echocardiography was performed prior to surgery, at three-month follow-up, and at three-year follow-up except for the latest nine patients. Results: The mean duration of follow-up was 3.6 ± 1.8 years. MVR surgery improved the functional class (mean New York Heart Association [NYHA] class) at three-year follow-up (p = 0.008). LV end-diastolic diameter and LA sizes decreased after MVR. Total chordal preservation causes better outcome, regarding to LV ejection fraction (LVEF) and NYHA functional class of patients. Preoperative high NYHA class, low LVEF, and high LV end-systolic diameter (LVESd) resulted with postoperative LV dysfunction (p were < 0.001, < 0.001, and 0.006, respectively). Conclusion: In patients with mixed mitral valve disease, MVR enhanced LV and LA remodeling resulting in better NYHA function. Preoperative NYHA, LVEF, and LVESd were significant predictors of postoperative LV function. (J Card Surg 2010;25:367-372) [source]


    Efficacy of Spironolactone on Survival in Dogs with Naturally Occurring Mitral Regurgitation Caused by Myxomatous Mitral Valve Disease

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2010
    F. Bernay
    Background: Spironolactone, an aldosterone antagonist, has been demonstrated to decrease mortality in human patients when added to other cardiac therapies. Hypothesis: Spironolactone in addition to conventional therapy increases survival compared with conventional therapy in dogs with naturally occurring myxomatous mitral valve disease (MMVD). Animals: Between February 2003 and March 2005, 221 dogs were recruited in Europe. Nine dogs were excluded from analysis, leaving 212 dogs with moderate to severe mitral regurgitation (MR) caused by MMVD (International Small Animal Cardiac Health Council classification classes II [n = 190] and III [n = 21]). Methods: Double-blinded, field study conducted with dogs randomized to receive either spironolactone (2 mg/kg once a day) or placebo in addition to conventional therapy (angiotensin converting enzyme inhibitor, plus furosemide and digoxin if needed). Primary endpoint was a composite of cardiac-related death, euthanasia, or severe worsening of MR. Results: Primary endpoint reached by 11/102 dogs (10.8%) in the spironolactone group (6 deaths, 5 worsening) versus 28/110 (25.5%) in control group (14 deaths, 8 euthanasia, 6 worsening). Risk of reaching the composite endpoint significantly decreased by 55% (hazard ratio [HR] = 0.45; 95% confidence limits [CL], 0.22,0.90; log rank test, P= .017). Risk of cardiac- related death or euthanasia significantly reduced by 69% (HR = 0.31; 95% CL, 0.13,0.76; P= .0071). Number of dogs not completing the study for cardiac and other miscellaneous reasons similar in spironolactone (67/102) and control groups (66/110). Conclusion and Clinical Importance: Spironolactone added to conventional cardiac therapy decreases the risk of reaching the primary endpoint (ie, cardiac-related death, euthanasia, or severe worsening) in dogs with moderate to severe MR caused by MMVD. [source]


    Insights into Serotonin Signaling Mechanisms Associated with Canine Degenerative Mitral Valve Disease

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
    M.A. Oyama
    Little is known about the molecular abnormalities associated with canine degenerative mitral valve disease (DMVD). The pathology of DMVD involves the differentiation and activation of the normally quiescent mitral valvular interstitial cell (VIC) into a more active myofibroblast phenotype, which mediates many of the histological and molecular changes in affected the valve tissue. In both humans and experimental animal models, increased serotonin (5-hydroxytryptamine, 5HT) signaling can induce VIC differentiation and myxomatous valve damage. In canine DMVD, numerous lines of evidence suggest that 5HT and related molecules such as transforming growth factor-, play a critical role in the pathogenesis of this disease. A variety of investigative techniques, including gene expression, immunohistochemistry, protein blotting, and cell culture, shed light on the potential role of 5HT in the differentiation of VIC, elaboration of myxomatous extracellular matrix components, and activation of mitogen-activated protein kinase pathways. These studies help support a hypothesis that 5HT and its related pathways serve as an important stimulus in canine DMVD. This review describes the pathological characteristics of canine DMVD, the organization and role of the 5HT pathway in valve tissue, involvement of 5HT in human and experimental models of valve disease, avenues of evidence that suggest a role for 5HT in naturally occurring DMVD, and finally, a overarching hypothesis describing a potential role for 5HT in canine DMVD. [source]


    Cardiac Troponin I Is Associated with Severity of Myxomatous Mitral Valve Disease, Age, and C-Reactive Protein in Dogs

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
    I. Ljungvall
    Background: Concentrations of cardiac troponin I (cTnI) and C-reactive protein (CRP) might be associated with cardiac remodeling in dogs with myxomatous mitral valve disease (MMVD). Age- and sex-dependent variations in cTnI concentration have been described. Objective: To investigate whether plasma concentrations of cTnI and CRP are associated with severity of MMVD, and investigate potential associations of dog characteristics on cTnI and CRP concentrations. Animals: Eighty-one client-owned dogs with MMVD of varying severity. Methods: Dogs were prospectively recruited for the study. Dogs were classified according to severity of MMVD. Plasma cTnI was analyzed by a high sensitivity cTnI assay with a lower limit of detection of 0.001 ng/mL, and plasma CRP was analyzed by a canine-specific CRP ELISA. Results: Higher cTnI concentrations were detected in dogs with moderate (0.014 [interquartile range 0.008,0.029] ng/mL, P= .0011) and severe (0.043 [0.031,0.087] ng/mL, P < .0001) MMVD, compared with healthy dogs (0.001 [0.001,0.004] ng/mL). Dogs with severe MMVD also had higher cTnI concentrations than dogs with mild (0.003 [0.001,0.024] ng/mL, P < .0001) and moderate (P= .0019) MMVD. There were significant associations of age, CRP, heart rate, and left ventricular end-diastolic diameter, on cTnI concentration C-reactive protein did not differ among severity groups, but was significantly associated with cTnI, breed, and systolic blood pressure on CRP concentration. Conclusions and Clinical Importance: Analysis of cTnI concentration has potential to increase knowledge of overall cardiac remodeling in dogs with MMVD. However, effect of age on cTnI needs consideration when assessing cTnI. [source]


    Evaluation of Pimobendan and N-Terminal Probrain Natriuretic Peptide in the Treatment of Pulmonary Hypertension Secondary to Degenerative Mitral Valve Disease in Dogs

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 6 2009
    K.J. Atkinson
    Background: Pimobendan is a positive inotrope and vasodilator that may be useful in the treatment of pulmonary hypertension (PHT) secondary to degenerative mitral valve disease. Hypothesis: Pimobendan decreases the severity of PHT measured echocardiographically and improves quality-of-life scores. Changes in N-terminal probrain natriuretic peptide (NT-proBNP) concentrations will reflect improvement in severity of PHT. Animals: Ten client-owned dogs with peak tricuspid regurgitant flow velocity (TRFV) ,3.5 m/s. Methods: Prospective short-term, double-blinded, crossover design, with a long-term, open-label component. Short term, dogs were randomly allocated to receive either placebo or pimobendan (0.18,0.3 mg/kg PO q12 h) for 14 days. After a 1-week washout, they received the alternative treatment for 14 days, followed by pimobendan open-label for 8 weeks. Results: Short-term comparison: peak TRFV decreased in all dogs on pimobendan compared with placebo from a median of 4.40 (range, 3.2,5.6) to 3.75 (range, 2.4,4.8) m/s (P < .0001). NT-proBNP concentration decreased after treatment with pimobendan from a median of 2,143 (range, 450,3,981) to 1,329 (range, 123,2,411) pmol/L (P= .0009). All dogs improved their quality-of-life score (P= .006). In the long-term comparisons, peak TRFV decreased in all dogs from a median of 4.28 (range, 3.5,5.7) to 3.52 (range, 2.4,5.0) m/s (P < .0001). No significant changes in NT-proBNP or quality-of-life scores were detected. Conclusions and Clinical Importance: Pimobendan lowered severity of measurable PHT, improved quality-of-life scores, and decreased NT-proBNP concentrations short-term. Long term, only the reduction in TRFV was maintained. [source]


    Tissue Doppler and Strain Imaging in Dogs with Myxomatous Mitral Valve Disease in Different Stages of Congestive Heart Failure

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 6 2009
    A. Tidholm
    Background: Tissue Doppler imaging (TDI) including strain and strain rate (SR) assess systolic and diastolic myocardial function. Hypothesis: TDI, strain, and SR variables of the left ventricle (LV) and the interventricular septum (IVS) differ significantly between dogs with myxomatous mitral valve disease (MMVD) with and without congestive heart failure (CHF). Animals: Sixty-one dogs with MMVD with and without CHF. Ten healthy control dogs. Methods: Prospective observational study. Results: Radial motion: None of the systolic variables were altered and 3 of the diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Longitudinal motion: 2 systolic velocities and 3 diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Difference in systolic velocity time-to-peak between LV and IVS was significantly increased in dogs with MMVD with and without CHF compared with control dogs. In total, 11 (23%) of 48 TDI and strain variables differed significantly between groups. Left atrial to aortic ratio was positively correlated to early diastolic velocities, percentage increase in left ventricular internal diameter in systole was positively correlated to systolic and diastolic velocities, and mitral E wave to peak early diastolic velocity in the LV basal segment (E/Em) was positively correlated to radial strain and SR. Conclusions and Clinical Importance: Few TDI and strain variables were changed in dogs with MMVD with and without CHF. Intraventricular dyssynchrony may be an early sign of MMVD or may be an age-related finding. [source]


    Effect of Pimobendan or Benazepril Hydrochloride on Survival Times in Dogs with Congestive Heart Failure Caused by Naturally Occurring Myxomatous Mitral Valve Disease: The QUEST Study

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2008
    J. Häggström
    Background: Myxomatous mitral valve disease (MMVD) continues to be an important cause of morbidity and mortality in geriatric dogs despite conventional therapy. Hypothesis: Pimobendan in addition to conventional therapy will extend time to sudden cardiac death, euthanasia for cardiac reasons, or treatment failure when compared with conventional therapy plus benazepril in dogs with congestive heart failure (CHF) attributable to MMVD. Animals: Two hundred and sixty client-owned dogs in CHF caused by MMVD were recruited from 28 centers in Europe, Canada, and Australia. Methods: A prospective single-blinded study with dogs randomized to PO receive pimobendan (0.4,0.6 mg/kg/d) or benazepril hydrochloride (0.25,1.0 mg/kg/d). The primary endpoint was a composite of cardiac death, euthanized for heart failure, or treatment failure. Results: Eight dogs were excluded from analysis. One hundred and twenty-four dogs were randomized to pimobendan and 128 to benazepril. One hundred and ninety dogs reached the primary endpoint; the median time was 188 days (267 days for pimobendan, 140 days for benazepril hazard ratio = 0.688, 95% confidence limits [CL] = 0.516,0.916, P= .0099). The benefit of pimobendan persisted after adjusting for all baseline variables. A longer time to reach the endpoint was also associated with being a Cavalier King Charles Spaniel, requiring a lower furosemide dose, and having a higher creatinine concentration. Increases in several indicators of cardiac enlargement (left atrial to aortic root ratio, vertebral heart scale, and percentage increase in left ventricular internal diameter in systole) were associated with a shorter time to endpoint, as was a worse tolerance for exercise. Conclusions and Clinical Importance: Pimobendan plus conventional therapy prolongs time to sudden death, euthanasia for cardiac reasons, or treatment failure in dogs with CHF caused by MMVD compared with benazepril plus conventional therapy. [source]


    Left Atrial Radiofrequency Ablation During Cardiac Surgery in Patients with Atrial Fibrillation

    JOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 12 2003
    ROBERTO MANTOVAN M.D.
    Introduction: Intraoperative left atrial radiofrequency (RF) ablation recently has been suggested as an effective surgical treatment for atrial fibrillation (AF). The aim of this study was to verify the outcome of this technique in a controlled multicenter trial. Methods and Results: One hundred three consecutive patients (39 men and 65 women; age 62 ± 11 years) affected by AF underwent cardiac surgery and RF ablation in the left atrium (RF group). The control group consisted of 27 patients (6 men and 21 women; age 64 ± 7 years) with AF who underwent cardiac surgery during the same period and refused RF ablation. Mitral valve disease was present in 89 (86%) and 25 (92%) patients, respectively (P = NS). RF endocardial ablation was performed in order to obtain isolation of both right and left pulmonary veins, a lesion connecting the previous lines, and a lesion connecting the line encircling the left veins to the mitral annulus. Upon discharge from the hospital, sinus rhythm was present in 65 patients (63%) versus 5 patients (18%) in the control group (P < 0.0001). Mean time of cardiopulmonary bypass was longer in the RF group (148 ± 50 min vs 117 ± 30 min, P = 0.013). The complication rate was similar in both groups, but RF ablation-related complications occurred in 4 RF group patients (3.9%). After a mean follow-up of 12.5 ± 5 months (range 4,24), 83 (81%) of 102 RF group patients were in stable sinus rhythm versus 3 (11%) of 27 in the control group (P < 0.0001). The success rate was similar among the four surgical centers. Atrial contraction was present in 66 (79.5%) of 83 patients in the RF group in sinus rhythm. Conclusion: Endocardial RF left atrial compartmentalization during cardiac surgery is effective in restoring sinus rhythm in many patients. This technique is easy to perform and reproducible. Rare RF ablation-related complications can occur. During follow-up, sinus rhythm persistence is good, and biatrial contraction is preserved in most patients. (J Cardiovasc Electrophysiol, Vol. 14, pp. 1289-1295, December 2003) [source]


    Course of Intraatrial Thrombi Resolution Using Transesophageal Echocardiography

    ECHOCARDIOGRAPHY, Issue 2 2003
    Jennifer A. Larsen M.D.
    Thromboembolic events are associated with atrial fibrillation and with cardioversion to sinus rhythm. Although studies have demonstrated the risk of this complication is reduced by a 3-week period of anticoagulation prior to cardioversion, limited data have suggested a longer period of anticoagulation is necessary for thrombus resolution. We identified and followed 25 patients noted to have intraatrial thrombi on an initial transesophageal echocardiogram (TEE) who subsequently had a follow-up TEE. The majority of patients had a single thrombus, often but not uniformly located in the left atrial appendage with the largest found in those patients with mitral stenosis. Repeat TEE was performed at a mean of 4 ± 6 months and persistent thrombus was noted in 19 of 25 patients (76%). Seven of 19 patients with persistent thrombi were cardioverted and one of these patients had a neurologic event following the procedure (14%). The only findings associated with persistent thrombus were the presence of mitral valve disease and atrial fibrillation.. Our findings suggest that intraatrial thrombi do not generally resolve following several weeks of anticoagulation and that persistent left-sided intraatrial thrombi may be associated with an increased risk for events following cardioversion. Given that a TEE-guided approach to cardioversion is being utilized more frequently, it may be important to determine thrombus characteristics on follow-up that would be predictive of embolic events following cardioversion. (ECHOCARDIOGRAPHY, Volume 20, February 2003) [source]


    Left Ventricle and Left Atrium Remodeling after Mitral Valve Replacement in Case of Mixed Mitral Valve Disease of Rheumatic Origin

    JOURNAL OF CARDIAC SURGERY, Issue 4 2010
    n Ender Topal M.D.
    Methods: Thirty consecutive elective patients with MVR for mixed mitral disease of rheumatic origin formed the study group. Of these, 21 (70%) were women and the mean age was 37 years. Transthoracic echocardiography was performed prior to surgery, at three-month follow-up, and at three-year follow-up except for the latest nine patients. Results: The mean duration of follow-up was 3.6 ± 1.8 years. MVR surgery improved the functional class (mean New York Heart Association [NYHA] class) at three-year follow-up (p = 0.008). LV end-diastolic diameter and LA sizes decreased after MVR. Total chordal preservation causes better outcome, regarding to LV ejection fraction (LVEF) and NYHA functional class of patients. Preoperative high NYHA class, low LVEF, and high LV end-systolic diameter (LVESd) resulted with postoperative LV dysfunction (p were < 0.001, < 0.001, and 0.006, respectively). Conclusion: In patients with mixed mitral valve disease, MVR enhanced LV and LA remodeling resulting in better NYHA function. Preoperative NYHA, LVEF, and LVESd were significant predictors of postoperative LV function. (J Card Surg 2010;25:367-372) [source]


    N-terminal pro B-type natriuretic peptide and left ventricular diameter independently predict mortality in dogs with mitral valve disease

    JOURNAL OF SMALL ANIMAL PRACTICE, Issue 2 2010
    W. Moonarmart
    Objectives: To determine whether natriuretic peptide concentrations would predict all cause mortality in dogs with degenerative mitral valve disease. Methods: One hundred dogs with naturally occurring degenerative mitral valve disease were prospectively recruited for this longitudinal study. Analysis of outcome was undertaken for 73 dogs for which the outcome was known. Dogs underwent physical examination, electrocardiography and echocardiography. Natriuretic peptide concentrations were measured by Enzyme-linked immunosorbent assay. The ability of natriuretic peptide concentrations, clinical, electrocardiographic and echocardiographic data, to predict all cause mortality was determined using univariable and multivariable Cox proportional hazards analyses. Results: Thirty dogs died during the period of follow-up. Two variables were independently predictive of all cause mortality; these were the normalised left ventricular end-diastolic diameter and the N-terminal pro B-type natriuretic peptide concentration. An increase of the left ventricular end-diastolic diameter by 0.1 increased the hazard of all cause mortality by 20% (95% confidence interval: 4 to 37%, P=0.01) and a 100 pmol/l increase in N-terminal pro B-type natriuretic peptide increased the hazard by 7% (95 confidence interval: 2 to 11%, P=0.003). Clinical Significance: N-terminal pro B-type natriuretic peptide concentration and left ventricular end-diastolic diameter are significantly and independently predictive of all cause mortality in dogs with degenerative mitral valve disease. [source]


    Neurohormonal activation in canine degenerative mitral valve disease: implications on pathophysiology and treatment

    JOURNAL OF SMALL ANIMAL PRACTICE, Issue 2009
    M. A. Oyama
    Neurohormonal systems play a critical role in canine degenerative mitral valve disease (DMVD). DMVD results in mitral regurgitation, which reduces forward cardiac output and increases intracardiac pressures. These changes trigger neurohormonal responses that ultimately result in maladaptive cardiac remodelling, congestion and heightened morbidity and mortality. Medical therapies such as ACE inhibitors and spironolactone derive their benefit by interrupting or suppressing these neurohormonal responses. Thus, knowledge of neurohormonal mechanisms can lead to a better understanding of how to treat DMVD. [source]


    Efficacy and safety of pimobendan in canine heart failure caused by myxomatous mitral valve disease

    JOURNAL OF SMALL ANIMAL PRACTICE, Issue 3 2005
    P. J. Smith
    Objectives: To evaluate the clinical efficacy and safety of pimobendan by comparing it with ramipril over a six-month period in dogs with mild to moderate heart failure (HF) caused by myxomatous mitral valve disease (MMVD). Methods: This was a prospective randomised, single-blind, parallel-group trial. Client-owned dogs (n=43) with mild to moderate HF caused by MMVD were randomly assigned to one of two groups, which received either pimobendan (P dogs) or ramipril (R dogs) for six months. The outcome measures studied were: adverse HF outcome, defined as failure to complete the trial as a direct consequence of HF; maximum furosemide dose (mg/kg/day) administered during the study period; and any requirement for additional visits to the clinic as a direct consequence of HF. Results: Treatment with pimobendan was well tolerated compared with treatment with ramipril. P dogs were 25 per cent as likely as R dogs to have an adverse HF outcome (odds ratio 4.09, 95 per cent confidence interval 1.03 to 16.3, P=0.046). Clinical Significance: R dogs had a higher overall score and thus may have had more advanced disease than P dogs at baseline (P=0.04). These results should be interpreted cautiously but such a high odds ratio warrants further investigation. [source]


    Efficacy of Spironolactone on Survival in Dogs with Naturally Occurring Mitral Regurgitation Caused by Myxomatous Mitral Valve Disease

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 2 2010
    F. Bernay
    Background: Spironolactone, an aldosterone antagonist, has been demonstrated to decrease mortality in human patients when added to other cardiac therapies. Hypothesis: Spironolactone in addition to conventional therapy increases survival compared with conventional therapy in dogs with naturally occurring myxomatous mitral valve disease (MMVD). Animals: Between February 2003 and March 2005, 221 dogs were recruited in Europe. Nine dogs were excluded from analysis, leaving 212 dogs with moderate to severe mitral regurgitation (MR) caused by MMVD (International Small Animal Cardiac Health Council classification classes II [n = 190] and III [n = 21]). Methods: Double-blinded, field study conducted with dogs randomized to receive either spironolactone (2 mg/kg once a day) or placebo in addition to conventional therapy (angiotensin converting enzyme inhibitor, plus furosemide and digoxin if needed). Primary endpoint was a composite of cardiac-related death, euthanasia, or severe worsening of MR. Results: Primary endpoint reached by 11/102 dogs (10.8%) in the spironolactone group (6 deaths, 5 worsening) versus 28/110 (25.5%) in control group (14 deaths, 8 euthanasia, 6 worsening). Risk of reaching the composite endpoint significantly decreased by 55% (hazard ratio [HR] = 0.45; 95% confidence limits [CL], 0.22,0.90; log rank test, P= .017). Risk of cardiac- related death or euthanasia significantly reduced by 69% (HR = 0.31; 95% CL, 0.13,0.76; P= .0071). Number of dogs not completing the study for cardiac and other miscellaneous reasons similar in spironolactone (67/102) and control groups (66/110). Conclusion and Clinical Importance: Spironolactone added to conventional cardiac therapy decreases the risk of reaching the primary endpoint (ie, cardiac-related death, euthanasia, or severe worsening) in dogs with moderate to severe MR caused by MMVD. [source]


    Insights into Serotonin Signaling Mechanisms Associated with Canine Degenerative Mitral Valve Disease

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
    M.A. Oyama
    Little is known about the molecular abnormalities associated with canine degenerative mitral valve disease (DMVD). The pathology of DMVD involves the differentiation and activation of the normally quiescent mitral valvular interstitial cell (VIC) into a more active myofibroblast phenotype, which mediates many of the histological and molecular changes in affected the valve tissue. In both humans and experimental animal models, increased serotonin (5-hydroxytryptamine, 5HT) signaling can induce VIC differentiation and myxomatous valve damage. In canine DMVD, numerous lines of evidence suggest that 5HT and related molecules such as transforming growth factor-, play a critical role in the pathogenesis of this disease. A variety of investigative techniques, including gene expression, immunohistochemistry, protein blotting, and cell culture, shed light on the potential role of 5HT in the differentiation of VIC, elaboration of myxomatous extracellular matrix components, and activation of mitogen-activated protein kinase pathways. These studies help support a hypothesis that 5HT and its related pathways serve as an important stimulus in canine DMVD. This review describes the pathological characteristics of canine DMVD, the organization and role of the 5HT pathway in valve tissue, involvement of 5HT in human and experimental models of valve disease, avenues of evidence that suggest a role for 5HT in naturally occurring DMVD, and finally, a overarching hypothesis describing a potential role for 5HT in canine DMVD. [source]


    Serum Cardiac Troponin I Concentration in Dogs with Precapillary and Postcapillary Pulmonary Hypertension

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
    C. Guglielmini
    Background: Pulmonary hypertension (PH) is a disease condition leading to right-sided cardiac hypertrophy and, eventually, right-sided heart failure. Cardiac troponin I (cTnI) is a circulating biomarker of cardiac damage. Hypothesis: Myocardial damage can occur in dogs with precapillary and postcapillary PH. Animals: One hundred and thirty-three dogs were examined: 26 healthy controls, 42 dogs with mitral valve disease (MVD) without PH, 48 dogs with pulmonary hypertension associated with mitral valve disease (PH-MVD), and 17 dogs with precapillary PH. Methods: Prospective, observational study. Serum cTnI concentration was measured with a commercially available immunoassay and results were compared between groups. Results: Median cTnI was 0.10 ng/mL (range 0.10,0.17 ng/mL) in healthy dogs. Compared with the healthy population, median serum cTnI concentration was increased in dogs with precapillary PH (0.25 ng/mL; range 0.10,1.9 ng/mL; P < .001) and in dogs with PH-MVD (0.21 ng/mL; range 0.10,2.10 ng/mL; P < .001). Median serum cTnI concentration of dogs with MVD (0.12 ng/mL; range 0.10,1.00 ng/mL) was not significantly different compared with control group and dogs with PH-MVD. In dogs with MVD and PH-MVD, only the subgroup with decompensated PH-MVD had significantly higher cTnI concentration compared with dogs with compensated MVD and PH-MVD. Serum cTnI concentration showed significant modest positive correlations with the calculated pulmonary artery systolic pressure in dogs with PH and some echocardiographic indices in dogs with MVD and PH-MVD. Conclusions and Clinical Importance: Serum cTnI is high in dogs with either precapillary and postcapillary PH. Myocardial damage in dogs with postcapillary PH is likely the consequence of increased severity of MVD. [source]


    Cardiac Troponin I Is Associated with Severity of Myxomatous Mitral Valve Disease, Age, and C-Reactive Protein in Dogs

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 1 2010
    I. Ljungvall
    Background: Concentrations of cardiac troponin I (cTnI) and C-reactive protein (CRP) might be associated with cardiac remodeling in dogs with myxomatous mitral valve disease (MMVD). Age- and sex-dependent variations in cTnI concentration have been described. Objective: To investigate whether plasma concentrations of cTnI and CRP are associated with severity of MMVD, and investigate potential associations of dog characteristics on cTnI and CRP concentrations. Animals: Eighty-one client-owned dogs with MMVD of varying severity. Methods: Dogs were prospectively recruited for the study. Dogs were classified according to severity of MMVD. Plasma cTnI was analyzed by a high sensitivity cTnI assay with a lower limit of detection of 0.001 ng/mL, and plasma CRP was analyzed by a canine-specific CRP ELISA. Results: Higher cTnI concentrations were detected in dogs with moderate (0.014 [interquartile range 0.008,0.029] ng/mL, P= .0011) and severe (0.043 [0.031,0.087] ng/mL, P < .0001) MMVD, compared with healthy dogs (0.001 [0.001,0.004] ng/mL). Dogs with severe MMVD also had higher cTnI concentrations than dogs with mild (0.003 [0.001,0.024] ng/mL, P < .0001) and moderate (P= .0019) MMVD. There were significant associations of age, CRP, heart rate, and left ventricular end-diastolic diameter, on cTnI concentration C-reactive protein did not differ among severity groups, but was significantly associated with cTnI, breed, and systolic blood pressure on CRP concentration. Conclusions and Clinical Importance: Analysis of cTnI concentration has potential to increase knowledge of overall cardiac remodeling in dogs with MMVD. However, effect of age on cTnI needs consideration when assessing cTnI. [source]


    Evaluation of Pimobendan and N-Terminal Probrain Natriuretic Peptide in the Treatment of Pulmonary Hypertension Secondary to Degenerative Mitral Valve Disease in Dogs

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 6 2009
    K.J. Atkinson
    Background: Pimobendan is a positive inotrope and vasodilator that may be useful in the treatment of pulmonary hypertension (PHT) secondary to degenerative mitral valve disease. Hypothesis: Pimobendan decreases the severity of PHT measured echocardiographically and improves quality-of-life scores. Changes in N-terminal probrain natriuretic peptide (NT-proBNP) concentrations will reflect improvement in severity of PHT. Animals: Ten client-owned dogs with peak tricuspid regurgitant flow velocity (TRFV) ,3.5 m/s. Methods: Prospective short-term, double-blinded, crossover design, with a long-term, open-label component. Short term, dogs were randomly allocated to receive either placebo or pimobendan (0.18,0.3 mg/kg PO q12 h) for 14 days. After a 1-week washout, they received the alternative treatment for 14 days, followed by pimobendan open-label for 8 weeks. Results: Short-term comparison: peak TRFV decreased in all dogs on pimobendan compared with placebo from a median of 4.40 (range, 3.2,5.6) to 3.75 (range, 2.4,4.8) m/s (P < .0001). NT-proBNP concentration decreased after treatment with pimobendan from a median of 2,143 (range, 450,3,981) to 1,329 (range, 123,2,411) pmol/L (P= .0009). All dogs improved their quality-of-life score (P= .006). In the long-term comparisons, peak TRFV decreased in all dogs from a median of 4.28 (range, 3.5,5.7) to 3.52 (range, 2.4,5.0) m/s (P < .0001). No significant changes in NT-proBNP or quality-of-life scores were detected. Conclusions and Clinical Importance: Pimobendan lowered severity of measurable PHT, improved quality-of-life scores, and decreased NT-proBNP concentrations short-term. Long term, only the reduction in TRFV was maintained. [source]


    Tissue Doppler and Strain Imaging in Dogs with Myxomatous Mitral Valve Disease in Different Stages of Congestive Heart Failure

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 6 2009
    A. Tidholm
    Background: Tissue Doppler imaging (TDI) including strain and strain rate (SR) assess systolic and diastolic myocardial function. Hypothesis: TDI, strain, and SR variables of the left ventricle (LV) and the interventricular septum (IVS) differ significantly between dogs with myxomatous mitral valve disease (MMVD) with and without congestive heart failure (CHF). Animals: Sixty-one dogs with MMVD with and without CHF. Ten healthy control dogs. Methods: Prospective observational study. Results: Radial motion: None of the systolic variables were altered and 3 of the diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Longitudinal motion: 2 systolic velocities and 3 diastolic velocities were significantly increased in dogs with CHF compared with dogs without CHF and control dogs. Difference in systolic velocity time-to-peak between LV and IVS was significantly increased in dogs with MMVD with and without CHF compared with control dogs. In total, 11 (23%) of 48 TDI and strain variables differed significantly between groups. Left atrial to aortic ratio was positively correlated to early diastolic velocities, percentage increase in left ventricular internal diameter in systole was positively correlated to systolic and diastolic velocities, and mitral E wave to peak early diastolic velocity in the LV basal segment (E/Em) was positively correlated to radial strain and SR. Conclusions and Clinical Importance: Few TDI and strain variables were changed in dogs with MMVD with and without CHF. Intraventricular dyssynchrony may be an early sign of MMVD or may be an age-related finding. [source]


    Effect of Pimobendan or Benazepril Hydrochloride on Survival Times in Dogs with Congestive Heart Failure Caused by Naturally Occurring Myxomatous Mitral Valve Disease: The QUEST Study

    JOURNAL OF VETERINARY INTERNAL MEDICINE, Issue 5 2008
    J. Häggström
    Background: Myxomatous mitral valve disease (MMVD) continues to be an important cause of morbidity and mortality in geriatric dogs despite conventional therapy. Hypothesis: Pimobendan in addition to conventional therapy will extend time to sudden cardiac death, euthanasia for cardiac reasons, or treatment failure when compared with conventional therapy plus benazepril in dogs with congestive heart failure (CHF) attributable to MMVD. Animals: Two hundred and sixty client-owned dogs in CHF caused by MMVD were recruited from 28 centers in Europe, Canada, and Australia. Methods: A prospective single-blinded study with dogs randomized to PO receive pimobendan (0.4,0.6 mg/kg/d) or benazepril hydrochloride (0.25,1.0 mg/kg/d). The primary endpoint was a composite of cardiac death, euthanized for heart failure, or treatment failure. Results: Eight dogs were excluded from analysis. One hundred and twenty-four dogs were randomized to pimobendan and 128 to benazepril. One hundred and ninety dogs reached the primary endpoint; the median time was 188 days (267 days for pimobendan, 140 days for benazepril hazard ratio = 0.688, 95% confidence limits [CL] = 0.516,0.916, P= .0099). The benefit of pimobendan persisted after adjusting for all baseline variables. A longer time to reach the endpoint was also associated with being a Cavalier King Charles Spaniel, requiring a lower furosemide dose, and having a higher creatinine concentration. Increases in several indicators of cardiac enlargement (left atrial to aortic root ratio, vertebral heart scale, and percentage increase in left ventricular internal diameter in systole) were associated with a shorter time to endpoint, as was a worse tolerance for exercise. Conclusions and Clinical Importance: Pimobendan plus conventional therapy prolongs time to sudden death, euthanasia for cardiac reasons, or treatment failure in dogs with CHF caused by MMVD compared with benazepril plus conventional therapy. [source]


    Biventricular Pacing for Severe Mitral Reguritation Following Atrioventrgicular Nodal Ablation

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2p1 2003
    PATRICK J.S. DISNEY
    DISNEY, P.J.S., et al.: Biventricular Pacing for Severe Mitral Regurgitation Following Atrioventricular Nodal Ablation. A 69-year-old woman developed acute pulmonary edema and severe mitral regurgitation (MR) 2 days following an uncomplicated AV nodal (AVN) ablation and insertion of VVI pacemaker for chronic atrial fibrillation. There was no history of significant mitral valve disease. Left ventricular function was normal and there was no evidence of an acute cardiac ischemic event. Transthoracic echo and right heart catheterization studies showed reduction in the severity of MR with biventricular pacing as opposed to RV pacing alone. A permanent pacemaker configured for biventricular pacing was implanted with complete resolution of symptoms and significant reduction in degree of MR. (PACE 2003; 26[Pt. I]:643,644) [source]


    Auscultation and echocardiographic findings in Bull Terriers with and without polycystic kidney disease

    AUSTRALIAN VETERINARY JOURNAL, Issue 5 2005
    CA O'LEARY
    Objective To investigate a possible association between Bull Terrier polycystic kidney disease (BTPKD) and cardiac disease, to determine the prevalence of mitral valve disease (MVD) and left ventricular outflow tract obstruction (LVOTO) in the Australian Bull Terrier population, and to compare auscultation and echocardiography in detection of cardiac disease in Bull Terriers. Design Ninety-nine Bull Terriers, ranging in age from 8 weeks to 13 years and 11 months were auscultated and examined using renal ultrasonography; 86 were also examined using echocardiography. The prevalence and severity of heart defects in dogs with BTPKD was compared with that in dogs without BTPKD. Results Nineteen of these 99 dogs were diagnosed with BTPKD. Forty-two percent of Bull Terriers with BTPKD and 28% of those without BTPKD had murmurs characteristic of mitral regurgitation or LVOTO. How recently an animal was descended from an ancestor with BTPKD was associated with presence (P = 0.008) and loudness of a murmur (P = 0.009). Overall, echocardiography detected MVD in 39% of Bull Terriers, with increased prevalence in older animals (P = 0.003). Mitral stenosis was found in eight cases. Fifty-three percent of dogs in this study had evidence of LVOTO, with obstruction consisting of a complex of lesions including dynamic or fixed subvalvular LVOTO, significantly narrowed left ventricular outflow tract or valvular aortic stenosis. Dogs with BTPKD, or those descended from dogs with BTPKD, were more likely to have MVD (P = 0.006), and while LVOTO was not more common in these dogs, if they did have LVOTO, they were more likely to have severe obstruction than dogs with no ancestors with BTPKD (analysed in three ways P = 0.028 to 0.001). In this study, 46% of Bull Terriers without a murmur or arrhythmia had cardiac disease detected on echocardiographic examination. Conclusion Cardiac disease, especially MVD and LVOTO, was common in Bull Terriers in this study, and those with BTPKD had an increased risk of cardiac abnormalities. Auscultation did not detect a significant number of Bull Terriers with cardiac disease. [source]