Tricuspid valve dysplasia: A retrospective study of clinical features and outcome in dogs in the UK

Evaluation of right ventricular diastolic function, systolic function, and circulating galectin-3 concentrations in dogs with pulmonary stenosis

BACKGROUND

Cardiovascular diseases with increased right ventricular (RV) afterload induce RV diastolic and systolic dysfunction, and myocardial fibrosis in humans. Studies in dogs with pulmonary stenosis (PS) evaluating RV diastolic function and markers of myocardial fibrosis are lacking.

HYPOTHESIS/OBJECTIVES

Dogs with PS have echocardiographic evidence of RV diastolic and systolic dysfunction and increased serum concentrations of galectin-3 (Gal-3), a surrogate biomarker for myocardial fibrosis.

ANIMALS

Forty client-owned dogs (10 controls, 30 with PS).

METHODS

Prospective study. All dogs had systemic blood pressure measurement, serum biochemical analysis, echocardiography, and measurement of serum Gal-3 concentration performed.

RESULTS

Variables of RV diastolic function were obtained in 39/40 dogs. Trans-tricuspid flow velocity in early diastole to trans-tricuspid flow velocity in late diastole ratios (RV E/A) were lower (P < .001) in dogs with PS (median, 0.94; range, 0.62-2.04) compared to controls (1.78; 1.17-2.35). Trans-tricuspid flow velocity in early diastole to tricuspid annular myocardial velocity in early diastole ratios (RV E/e') were higher (P < .001) in dogs with PS (11.55; 4.69-28) compared to control (6.21; 5.16-7.21). Variables of RV systolic function were lower in dogs with PS (P = <.001). Serum Gal-3 concentration was higher (P = .002) in dogs with PS (285.1 pg/mL; 94.71-406.97) compared to control dogs (162.83 pg/mL; 52.3-232.82).

CONCLUSIONS AND CLINICAL IMPORTANCE

Dogs with PS have RV diastolic and systolic dysfunction, and increased Gal-3 concentrations. These findings suggest the presence of RV myocardial fibrosis in dogs with PS, which could impact clinical management.

Cardiac Disease and Screening in Breeding Dogs

Acquired and congenital heart diseases are relatively common in dogs, particularly in certain breeds. Modes of inheritance and genetic causes have been established for several cardiac diseases within various breeds. Breed screening is used to try and reduce the prevalence of certain canine cardiac diseases. Although breed screening seems to help reduce the prevalence of canine heart disease, the outcomes of specific breeding programs are variable and depend on multiple factors.

Systolic function in dogs with pulmonic stenosis of different severities and the effect of balloon valvuloplasty

INTRODUCTION/OBJECTIVES

Pulmonic stenosis (PS) is one of the most common congenital heart diseases in dogs leading to right ventricular (RV) pressure overload, myocardial remodeling, and potential RV dysfunction. Our objectives were to investigate the extent of RV systolic dysfunction in canine PS and to examine the immediate influence of balloon valvuloplasty (BV) on systolic function.

ANIMALS, MATERIALS AND METHODS

This prospective study evaluated 72 dogs with PS and 86 healthy dogs. Echocardiographic parameters of systolic function included normalized tricuspid annular plane systolic excursion (N-TAPSE), normalized systolic myocardial tissue Doppler velocity of the lateral tricuspid annulus (N-RVFW-S'), fractional area change, and speckle-tracking longitudinal endocardial RV strain. Forty-four dogs underwent BV and were re-examined after surgery.

RESULTS

Systolic function at the basal segment of the RV was significantly lower in the PS group when compared to healthy dogs (mean N-TAPSE 4.29 ± standard deviation 1.18 mm/kg^0.285 vs. 5.60 ± 1.29 mm/kg^0.285; median N-RVFW-S' 5.28 [lower-upper 25% quantile 4.35-6.43 cm/s/kg^0.186] vs. 7.82 [6.73-8.79 cm/s/kg^0.186]; all P<0.001). Global longitudinal RV endocardial strain showed no significant difference between the two groups (-28.50 ± 6.23% vs. 28.61 ± 4.64%; P=0.886), but segmental strain analyses revealed basal hypo- and potential compensatory hyperkinesis of the apical RVFW. Furthermore, BV affected most parameters of systolic function, but not the segmental strain values and N-TAPSE.

CONCLUSIONS

Right ventricular basal longitudinal systolic function is decreased in dogs with PS in comparison to a healthy cohort. Regional and global function does not necessarily coincide.

Key considerations in the approach to congenital heart disease in dogs and cats

Congenital heart disease is an important subset of all cardiovascular disease in dogs and cats that is present at birth and most often detected in young animals but can be diagnosed in adulthood. The range of abnormalities that can occur during development of the heart is vast incorporating simple and complex defects, varying degrees of severity and clinical presentations that include heart failure and cyanosis. While some defects do not result in morbidity in an individual animal, others cause severe clinical signs and death at a young age. Advances in imaging and expanding treatment options offer increasingly more possibilities in the diagnosis and management of congenital heart disease which is the focus of this review. The objective is to provide a broad overview of current practice and highlight key aspects to guide practitioners in their approach to congenital heart disease diagnosis and knowledge of available treatment options.

Surgical repair for canine tricuspid valve dysplasia: Technique and case report

Tricuspid valve dysplasia (TVD) is a congenital malformation of the right atrioventricular valve characterized by restricted leaflet motion, annular dilation, and tricuspid regurgitation (TR). Severe cases typically exhibit progressive right-sided congestive heart failure, affecting the quality of life and survival. This article describes a technique for surgical repair of TVD and a case report with long-term follow-up. A 1.5-year-old intact male Labrador retriever with severe TR underwent surgical repair for TVD. Valve repair was performed under cardiopulmonary bypass and consisted of neochord mobilization of the valve leaflets and partial band annuloplasty. Transthoracic echocardiogram performed 5 days after surgery showed mild TR, a 93% decrease in anatomic regurgitant orifice area, and decreased right chamber dimensions. Forty-eight months after repair, the patient was free of clinical signs, did not have a heart murmur, and was receiving no cardiac medications. Based on this case, surgical repair of TVD is feasible with long-term durability, and the outcome suggests that the described technique may be a viable treatment option for patients with severe TVD.

Diagnosis and management of canine atrial fibrillation

Atrial fibrillation (AF) is the most common non-physiological arrhythmia in dogs and humans. Its high prevalence in both species and the impact it has on survival time and quality of life of affected patients, makes it a very relevant topic for medical research. In dogs, the diagnosis of AF is usually fairly straightforward, but optimal management can be complicated. Rate control is the most commonly used strategy; rhythm control can also be considered in very specific cases. Concurrent congestive heart failure is frequently identified, which represents an extra challenge for the clinicians. This article reviews the current recommendations for the diagnosis and management considerations of AF in dogs. Future perspectives, focusing on new drugs that may prevent development of AF based on recent discoveries, will also be discussed.

Canine atrial fibrillation: Pathophysiology, epidemiology and classification

Atrial fibrillation (AF) is the most common non-physiological arrhythmia in dogs and humans. Its high prevalence in both species and the impact it has on survival time and quality of life of affected patients, makes it a very relevant topic of medical research. Significant developments in understanding the mechanisms underlying this arrhythmia in humans has occurred over the last decades and some of this knowledge is being applied to veterinary medicine, despite the many differences between species. This article reviews the current understanding of the pathophysiology of AF. The epidemiology and classification of AF in dogs will also be discussed.

Epidemiological, clinical, and echocardiographic features, and outcome of dogs with Ebstein's anomaly: 32 cases (2002-2016)

INTRODUCTION/OBJECTIVES

Ebstein's anomaly (EA) is a congenital heart disease characterized by apical displacement of the tricuspid valve leaflets in the right ventricle. The objective of this retrospective study was to investigate the signalment, clinical features, echocardiographic findings, and outcome of dogs with EA.

ANIMALS, MATERIALS AND METHODS

Medical records of 40 dogs with EA were reviewed. Echocardiographic variables used to assess EA severity in human pediatrics were also evaluated (e.g. displacement index, Celermajer index, Carpentier class, and apex-mitral annulus:apex-tricuspid annulus distance ratio).

RESULTS

Labrador retriever was the most commonly recruited breed (24 of the 40 dogs, 60%). Eight of the 40 dogs with EA had hemodynamically compromising concurrent heart (n = 7) or respiratory diseases (n = 1). A right apical systolic heart murmur (median grade = 5/6) was detected in the remaining 32 dogs, without any other clinical sign related to EA in 19 of the 32 dogs (59%). Median (interquartile range) values of the displacement index and Celermajer index were 17.4 mm/m² (12.0-21.9) and 100% (50-130), respectively. Median time to all-cause death was 74 months, and 72% dogs (95% confidence interval, 50-86%) had not succumbed to cardiac death (CD) 160 months after diagnosis. Univariate analyses showed that the time from diagnosis to CD was associated with the presence of clinical signs, ascites, severe right atrial dilation, palpable thrill, and a Celermajer index ≥100%.

DISCUSSION

Right atrial enlargement is significantly associated with decreased survival time of dogs with EA although most may live for years and may not die from CD.

CONCLUSIONS

These results support medium to long-term survival for most dogs with EA.

The utility of point-of-care ultrasound right-sided cardiac markers as a screening test for moderate to severe pulmonary hypertension in dogs

Dogs with respiratory disease can develop pulmonary hypertension (PH), a comorbid condition that can impact therapy and prognosis. Without confirmation using the criterion standard of echocardiography, this complication may be missed. Point-of-care ultrasound (POCUS) is a simple, non-invasive screening test that may suggest PH. It was hypothesized that in dogs POCUS right-sided cardiac markers (R-SCM) at the subxiphoid view would predict moderate to severe PH confirmed by echocardiography. Forty-three client-owned dogs that underwent respiratory evaluation with POCUS and echocardiography were included. POCUS R-SCM evaluated in the subxiphoid view included subjective caudal vena cava distention (CVC_sx), CVC_sx >1cm, gallbladder wall edema and ascites. PH was defined by tricuspid regurgitation pressure gradient (TRPG) as mild (30-49.9mmHg), moderate (50-74.9mmHg) or severe (>75mmHg). POCUS subxiphoid views were blindly evaluated post hoc and compared to echocardiography. Chi square test and one-way ANOVA were used to evaluate correlations between POCUS R-SCM and echocardiographic diagnosis of moderate to severe PH. Twenty-six dogs with PH, and 17 dogs without PH, were enrolled. There was no significant difference in the presence or absence of any R-SCM between dogs with and without PH. When dogs with no PH and mild PH were grouped and compared to dogs with moderate to severe PH (i.e., dogs for which treatment for PH would be recommended), no significant differences in R-SCM were noted. POCUS R-SCM using the CVC_sx view was not a sensitive screening test to identify dogs with PH in this study population.