Article

Associations between cardiac pathology and clinical, echocardiographic and electrocardiographic findings in dogs with chronic congestive heart failure

Department of Basic Animal and Veterinary Sciences, The Faculty of Life Sciences, University of Copenhagen, Frederiksberg, Denmark.
The Veterinary Journal (Impact Factor: 2.17). 07/2010; 185(1):68-74. DOI: 10.1016/j.tvjl.2010.04.016
Source: PubMed

ABSTRACT The objective of this study was to correlate defined pathological features with clinical findings in dogs with naturally occurring congestive heart failure (CHF). Fifty-eight dogs with CHF were examined clinically and using echocardiography and electrocardiography. Detailed cardiac post-mortem examination was used to assess intra-myocardial arterial narrowing, myocardial fibrosis and atrophy and myxomatous mitral valve degeneration (MMVD). Arterial narrowing significantly correlated with fibrosis (P<0.0001) and with fractional shortening, an indicator of systolic function (P=0.002). The grade of fibrosis was associated with shorter survival time (P=0.002), and the papillary muscle fibrosis score tended to correlate with proximal isovelocity surface area radius (P=0.03). Data from this study lend support to the hypothesis that naturally occurring canine CHF is affected by several factors such as MMVD, myocardial atrophy and fibrosis, and by arteriosclerosis. Further, more extensive research will be required to establish cause-effect relationships between these cardiac lesions and the pathophysiology of CHF in dogs.

0 Followers
 · 
88 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: Few previous studies have investigated the association between biomarkers and cardiac disease findings in dogs with naturally occurring myxomatous mitral valve disease (MMVD). AIM: To investigate if histopathological changes at necropsy could be reflected by in vivo circulating concentrations of cTnI and aldosterone, and renin activity, in dogs with naturally occurring congestive heart failure because of MMVD. ANIMALS: Fifty privately owned dogs with MMVD and heart failure. METHODS: Longitudinal Study. Dogs were prospectively recruited and examined by clinical and echocardiographical examination twice yearly until time of death. Blood was stored for batched analysis of concentrations of cTnI and aldosterone, and renin activity. All dogs underwent a standardized necropsy protocol. RESULTS: cTnI were associated with echocardiographic left ventricular end-diastolic dimension (P < .0001) and proximal isovolumetric surface area radius (P < .004). Furthermore, in vivo cTnI concentrations reflected postmortem findings of global myocardial fibrosis (P < .001), fibrosis in the papillary muscles (P < .001), and degree of arterial luminal narrowing (P < .001) Aldosterone or renin activity did not reflect any of the cardiac disease variables investigated. CONCLUSION AND CLINICAL IMPORTANCE: Cardiac fibrosis and arteriosclerosis in dogs with MMVD are reflected by circulating cTnI concentration, but not by aldosterone concentration or renin activity. Cardiac troponin I could be a valuable biomarker for myocardial fibrosis in dogs with chronic cardiac diseases.
    Journal of Veterinary Internal Medicine 04/2013; DOI:10.1111/jvim.12075 · 2.22 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Objectives To evaluate associations between N-terminal procollagen type III (PIIINP), a serum biomarker of collagen biosynthesis, and myocardial fibrosis in dogs with naturally-occurring myxomatous mitral valve disease (MMVD). Animals Twenty-two dogs with echocardiographically-confirmed MMVD were prospectively recruited from a hospital population. All died as a result of MMVD and their hearts were available for post mortem examination. Methods Echocardiographic measurements and serum PIIINP concentrations were obtained from all dogs prior to death or euthanasia. Serum PIIINP concentrations (μg/mL) were measured using a validated commercially available radioimmunoassay. Myocardial tissue samples were collected post mortem and myocardial fibrosis was scored. The average fibrosis score for all cardiac sites in the heart was designated the global fibrosis score (GFS). The average fibrosis score for all papillary muscle sites was designated the papillary fibrosis score (PFS). Univariate and multivariate linear regression analyses were used separately to evaluate associations between GFS and PFS, respectively, and PIIINP and echocardiographic variables. Results Left ventricular end-diastolic diameter normalized for body weight (LVEDDN) and PIIINP were weakly independently positively associated with both GFS and PFS. LVEDDN and PIIINP were weakly negatively correlated. Conclusions Both LVEDDN and serum PIIINP increase with increasing fibrosis score, although these relationships were not strong enough to be clinically useful. Although LVEDDN and PIIINP were positively correlated with fibrosis, PIIINP decreased with increasing LVEDDN, suggesting a complex interplay between fibrosis and remodeling in MMVD.
    Journal of Veterinary Cardiology 09/2014; 16(4). DOI:10.1016/j.jvc.2014.08.002
  • [Show abstract] [Hide abstract]
    ABSTRACT: BACKGROUND: During the cardiac cycle, the ventricle undergoes a twisting motion because of the oblique orientation of the left ventricular (LV) myofibers. This can be quantified by speckle-tracking echocardiography (STE). In mitral regurgitation (MR) in humans, the short axis deformation has been suggested as being pivotal to LV function. Decreased and delayed LV twist has been described in experimental MR, but has not been studied in myxomatous mitral valve disease (MMVD). HYPOTHESES: (1) Magnitude (CSt) and rate (CSRs) of systolic circumferential deformation decrease before the onset of congestive heart failure (CHF); (2) magnitude and rate of LV twist decrease, and onset of untwist is delayed, with increasing MMVD severity. ANIMALS: A total of 97 privately owned small- to medium-sized dogs. METHODS: Severity of MMVD was assessed by echocardiography and presence of clinical signs of CHF. Magnitude and rate of LV twist and circumferential deformation were evaluated by STE. RESULTS: Dogs with CHF receiving treatment had increased CSt, CSRs, early diastolic untwisting rate, and delayed onset of untwist compared to dogs with minimal MMVD and increased systolic twist compared to dogs with mild MMVD (all P < .01). CSt and time to onset of untwist increased with echocardiographic variables of MR severity (all P < .002). CSRs and several LV twist variables decreased with increasing systolic LV internal diameter (all P < .01). CONCLUSIONS AND CLINICAL IMPORTANCE: No STE-derived variable was decreased before onset of CHF. In dogs with CHF receiving treatment, the delayed onset of relaxation might indicate LV dysfunction and the hyperdynamic CSt and LV twist reflect compensatory mechanisms.
    Journal of Veterinary Internal Medicine 06/2013; 27(4). DOI:10.1111/jvim.12114 · 2.22 Impact Factor