Serum Cardiac Troponin I Concentration in Retired Racing Greyhounds

Background: Cardiac troponin I (cTnI) is a polypeptide found specifically in cardiac muscle tissue that has been used as a diagnostic and prognostic indicator of cardiomyopathy. Increases in cTnI are associated with myocardial pathologic processes. However, high serum cTnI concentrations have been observed in normal Greyhounds.
Hypothesis: We hypothesized that Greyhounds have cTnI concentrations higher than non-Greyhound dogs, and that a separate reference range should be established for Greyhounds.
Animals: Blood samples were collected from the jugular vein from a group of 20 healthy Greyhound blood donors.
Methods: Analysis of serum cTnI was performed with an immunoassay system with a detection level of 0.01 ng/mL, as described previously. The Greyhound values were compared with 2 groups of Boxers with and without arrhythmogenic right ventricular cardiomyopathy (ARVC), and to a group of non-Boxer control dogs from a previous study.
Results: The mean cTnI concentration in Greyhounds was significantly higher ( P < .0001) than that in non-Greyhound control dogs, although not significantly different from normal Boxers ( P = .50), or Boxers with ARVC ( P = .58). Greyhound serum cTnI concentrations were in the range found in Boxers with ARVC. The proposed reference range for cTnI in Greyhounds is 0.05–0.16 ng/mL.
Conclusions and Clinical Importance: Greyhounds have a reference range for serum cTnI concentrations that differs from that of other previously published reference ranges for dogs of other breeds. Until a broader database and more precise reference range can be established, caution should be exercised in interpreting serum cTnI concentrations in Greyhounds with suspected cardiac disease.     

Balloon dilation of an imperforate cor triatriatum dexter in a Golden Retriever with concurrent double-chambered right ventricle and subsequent evaluation by cardiac magnetic resonance imaging

A 12-week-old male Golden Retriever was presented with signs of right-sided congestive heart failure and a grade V/VI left craniosternal systolic murmur. Echocardiography identified a double-chambered right ventricle and dilated coronary sinus (CS) running into an inter-atrial chamber. This was confirmed to be an imperforate cor triatriatum dexter (CTD) by selective angiographic studies. To the authors’ knowledge this is the first case reported of imperforate CTD successfully treated by membranostomy and balloon dilation. Cardiac MRI confirmed the echocardiographic and angiographic findings and provided a more precise understanding of the venous abnormalities.     

Reference Values and Repeatability of B-Mode and M-Mode Echocardiographic Parameters in Healthy Donkey (Equus asinus)—The Guide to Assess Healthy Heart

Donkey (Equus asinus), the cheapest form of agricultural power in Egypt, is used principally as draught or pack animals and may also be ridden, or used for threshing, raising water, milling, and other work. The aim of the present study was to provide B-mode and M-mode echocardiographic reference ranges from a sample of population of donkeys (E. asinus) based on the probability theory and statistics. In the present study, B-mode and 2-dimensional guided M-mode echocardiography were performed on 44 clinically healthy donkeys (E. asinus) (22 males and 22 females), without any neither clinical nor echocardiographic evidence of cardiovascular diseases, aged 2–25 year old, and weighed 150–350 kg. The echocardiographic dimensions, including interventricular septum thickness at end diastole, interventricular septum thickness at end systole, left ventricular internal diameter at end diastole, left ventricular internal diameter at end systole, left ventricular posterior wall thickness at end diastole, and left ventricular posterior wall thickness at end systole were assessed. The cardiac function indices, including end diastolic volume, end systolic volume, stroke volume, ejection fraction, and fractional shortening were also measured. B-mode and guided M-mode echocardiographic examination of healthy donkeys revealed that both the interventricular septum thickness and the left ventricular posterior free wall were greater during systole than diastole. However, the left ventricular dimension during diastole was greater than systole. Furthermore, the recorded data of cardiac function indices, including end diastolic volume, end systolic volume, stroke volume, ejection fraction, and fractional shortening using B-mode echocardiography were closer to those recorded by guided M-mode echocardiography. To our knowledge, this is the first Egyptian study to report the echocardiographic reference ranges of donkeys (E. asinus) based on the probability theory and statistics, the coefficient of variation. The results of the present study can be used as standard and reference values for further echocardiographic studies in donkeys and represent a step in the identification, interpretation, and evaluation of cardiovascular disorders in such animals.     

Extracardiac intrapericardial myxosarcoma causing right ventricular outflow tract obstruction in a dog

A 13-year-old male castrated pomeranian cross was referred for evaluation of episodes of collapse and a suspected cardiac mass. The presence of a mass at the base of the heart within the pericardial space was confirmed by echocardiography. Additional diagnostics included computed tomography, ultrasound-guided fine-needle aspirate, and thoracic radiographs. The mass was surgically debulked and diagnosed as myxosarcoma via histopathology. This case report describes the diagnostic imaging, laboratory findings, and short-term positive clinical outcome of a dog with a myxosarcoma in a previously undescribed location.     

Biochemical markers of cardiac injury in normal, surviving septic, or nonsurviving septic neonatal foals

The cardiac biomarkers cardiac troponin T (cTnT) and I (cTnI) and the cardiac isoenzyme of creatine kinase (CKMB) are used extensively in human medicine to diagnose and provide valuable prognostic information in patients with ischemic, traumatic, and septic myocardial injury. We designed a study to establish normal values for these markers in healthy, neonatal foals and to compare them with values obtained from septic neonates in a referral hospital population. The 25th, 50th, 75th, and 95th percentiles for cTnI and CKMB in the healthy-foal population were 0.08, 0.14, 0.25, 0.49 ng/mL and 1.4, 2.3, 4.0, 7.4 ng/mL, respectively. The values obtained for cTnT were frequently (43/52 foals; 83%) below the lower limit of detection of the assay (0.009 ng/mL), but the median and range were 0.009 and 0.009-0.041 ng/mL, respectively. In the septic foal population, the 25th, 50th, 75th, and 95th percentile values for cTnI and CKMB were 0.05, 0.12, 0.22, and 1.10 ng/mL and 2.0, 4.4, 7.8, and 24 ng/mL, respectively. The values obtained for cTnT were less frequently below the lower limit of detection (23/38 foals; 60%) compared with the healthy foal population, and the median and range were 0.009 and 0.009-0.20 ng/mL, respectively. Significantly higher values were observed for cTnT and CKMB in septic foals compared with the healthy neonatal foal population, but there were no differences among septic foals in survivors compared with nonsurvivors. These findings suggest that myocardial injury occurs during septicemia in neonatal foals but that the injury is not associated with survival among septic foals.     

Balloon valvuloplasty of congenital mitral stenosis

Radiographic, echocardiographic, fluoroscopic, and angiographic images from 2 dogs with severe congenital mitral valve stenosis that underwent cardiac catheterization and balloon valvuloplasty are presented. Both dogs displayed systolic doming of the mitral valve leaflets, increased diastolic pressure gradient across the left atrium and ventricle, and decreased mitral inflow E to F slope. Balloon valvuloplasty was performed on both dogs using atrial transeptal puncture.     

M-mode echocardiographic ratio indices in normal dogs, cats, and horses: a novel quantitative method

A novel method for quantitative echocardiographic interpretations is introduced based on the calculation of ratio indices in which each raw M-mode measurement is divided by the aortic root dimension (Ao). "Aorta-based" indices were calculated with the animal's measured aortic root dimension (Ao(m)) as the length standard. Conversely, "weight-based" indices employed an idealized estimate of aortic dimension (Ao(w)) with a weighted least squares linear regression against the cube root of body weight (Ao(w) = kW(1/3)). Use of these indices circumvented undesirable statistical characteristics inherent in linear regression of echocardiographic dimensions against body weight and, to a lesser extent, body surface area. Compared with the regressions, ratio indices resulted in substantial refinement of the predictive range for each M-mode measurement in dogs, particularly with decreasing body size. Weight-based indices outperformed aorta-based indices in this regard. To refine the predictive range, neither type of index was clearly advantageous in cats compared with the simple average method typically employed for that species. Several of the raw M-mode measurements, however, were correlated with body weight in cats and horses, indicating the need for an appropriate correction for body size in these species. The ratio index method was suitable for this purpose. Summary statistics derived from normal dogs (n = 53), cats (n = 32), and horses (n = 17) are presented for each index, including novel clinical indices calculated from area ratios. The latter were designed to represent body size-adjusted lett ventricular stroke area (ie, volume overload) and myocardial wall area (ie, hypertrophy).     

Cardiac troponin I in the normal dog and cat

Cardiac troponin I (cTnI) has proven to be a highly specific and sensitive marker for myocardial cellular damage in many mammalian species. The structure of cTnI is highly conserved across species, and assays for human cTnI (including the one used in the current study) have been validated in the dog. Blood concentrations of cTnI rise rapidly after cardiomyocyte damage, and assay of cTnI potentially may be valuable in many clinical diseases. The purpose of this study was to establish the normal range of cTnI in heparinized plasma of dogs and cats. Forty one clinically normal dogs and 21 cats were included in the study. One to 3 milliliters of blood were collected by venipuncture into lithium heparin vacutainers for analysis of cTnI (Stratusz CS). The range of plasma cTnI concentrations in dogs was <0.03 to 0.07 ng/mL with a mean of 0.02 ng/mL, with the upper tolerance limit (0.07 ng/mL) at the 90th percentile with 95% confidence. In cats, the range was <0.03 to 0.16 ng/mL with a mean of 0.04 ng/mL, and the upper tolerance limit (0.16 ng/mL) at the 90th percentile as well with 90% confidence. This study establishes preliminary normal ranges of plasma cTnI in normal dogs and cats for comparison to dogs and cats with myocardial injury or disease.     

Cardiovascular effects of intravenous diltiazem in dogs with iatrogenic atrial fibrillation

Atrial fibrillation (AF) was induced in anesthetized Beagle hounds to determine the dose of diltiazem (D) that resulted in hemodynamic function similar to that observed during sinus rhythm (SR). Dogs were instrumented to record hemodynamic and electrophysiological parameters. Six dogs were given D, IV at cumulative doses of 0.063, 0.188, 0.438, 0.938, and 1.938 mg/kg, whereas 6 other dogs received vehicle in equivalent volumes. Plasma concentrations (PC) of D were measured. A cumulative dose of D between 0.438 and 0.938 mg/kg produced PC of 67.8 to 117.4 ng/mL and resulted in a heart rate (HR) closest to that observed during SR. At doses up to 0.938 mg/kg, no parameter of systolic function fell below that obtained during SR. At a dose of 0.938 mg/kg, the left ventricular end-diastolic and right atrial pressures exceeded those during SR. The rate-pressure product did not differ from that during SR at a dose of 0.938 mg/kg and fell below that during SR at the dose of 1.938 mg/kg. Left ventricular efficiency decreased from SR to AF, returned to values not different from those during SR at a dose of 0.938 mg/kg, and increased to values above those observed during SR at a dose of 1.938 mg/kg. In AF, slowing the HR with 0.438-0.938 mg/kg of D with resultant PC of 67.8-117.4 ng/mL results in cardiovascular function not different from that observed during SR.     

Comparative study of 4 echocardiographic methods of left ventricular measurement in German Shepherd dogs

ObjectivesTo compare dimensions and shortening fraction (SF) of the left ventricle (LV) obtained from two-dimensional (2D) and M-mode imaging of short and long-axis views.Animals40 healthy, adult German Shepherd dogs.MethodsLeft ventricular measurements were obtained using 4 echocardiographic methods: M-mode in short and long-axis and 2D imaging in short and long-axis. The methods were compared by studying the effects of imaging mode and axis on LV parameters, taking into account the influence of weight and gender.ResultsMean LV end-diastolic diameter was greater in short-axis views. However, this difference was not considered clinically relevant. Mean SF was higher when derived from 2D measurements with poor agreement among methods. A combined influence of axis, gender, and weight was observed on interventricular septal thickness in end diastole with poor agreement among methods.ConclusionsSome LV parameters were significantly affected by mode and axis, either in isolation or in combination with weight and gender, although the differences observed were not always clinically relevant. These findings show that using the different echocardiographic methods interchangeably to assess LV dimensions should be done with caution.     

Applications, complications, and outcomes of transvenous pacemaker implantation in 105 dogs (1997-2002)

We reviewed the indications for age and breeds of dogs who received transvenous endocardial artificial pacemaker (AP) implantation (n = 105) and complications and survival thereafter at a single institution over a 6-year period. A third-degree atrioventricular (AV) block (59%) and sick sinus syndrome (SSS; 27%) were the most common indications, along with a high-grade second-degree AV block (9%) and atrial standstill (5%). The most common breeds identified were Labrador Retriever (n = 16; 11 with a third-degree AV block), American Cocker Spaniel (n = 14; 10 with SSS), and Miniature Schnauzer (n = 13; all with SSS). Common presenting complaints were syncope (n = 66) and exercise intolerance or lethargy (n = 25). Half of the dogs (n = 52) had a history of acute onset of clinical signs (<2 weeks). Mean survival time for the 60 dogs who died during the study period was 2.2 years (range, 0.1-5.8 years). Major complications occurred in 13% of dogs and included lead displacement (n = 7), sensing problems that led to syncope (n = 3), infection at the pacemaker site (n = 1), bleeding (n = 1), and ventricular fibrillation during implantation (n = 1; successfully defibrillated). Minor complications occurred in 11 dogs (11%). The success rate of transvenous AP implantation was comparatively high (all dogs survived the first 48 hours), and the complication rate was comparatively low when compared with a previous multicenter study, most likely because of how commonly the procedure was performed and supervisory experience.     

Association of body weight and body condition with survival in dogs with heart failure

BACKGROUND: Obesity is a risk factor for cardiovascular disease in people, but overweight and obese human heart failure patients have improved survival compared with normal--or underweight controls--the obesity paradox. The purpose of this study was to determine if there is an association of body weight and body condition with survival in dogs with heart failure. HYPOTHESIS: That body condition and changes in body weight are predictors of survival in dogs with heart failure. ANIMALS: One hundred and eight dogs with heart failure (International Small Animal Cardiac Health Council stages 2, 3a, or 3b) secondary to dilated cardiomyopathy or chronic valvular disease. METHODS: Medical records were reviewed, and data regarding initial body weight and body condition score (BCS), subsequent changes in body weight, and treatment were collected. Survival times were determined for dogs that were discharged from the hospital and lived >24 hours. RESULTS: Survival was significantly different between dogs that gained, lost, or maintained body weight over the course of their disease (P= .04), with dogs that gained weight surviving the longest. BCS and medications were not significantly associated with survival time; however, n-3 fatty acid intake was associated with longer survival time (P= .009). CONCLUSIONS AND CLINICAL IMPORTANCE: These results suggest that changes in body weight might be an important consideration in the survival of dogs with heart failure.     

Use of Multidetector Computed Tomography in the Assessment of Dogs with Pericardial Effusion

Background

Contrast‐enhanced multidetector computed tomography (MDCT) allows high spatial and temporal resolution imaging of cardiac, thoracic, and abdominal structures. Accurate determination of the cause of pericardial effusion (PE) is essential to providing appropriate treatment and prognosis. Echocardiography and pericardial fluid analysis may not differentiate between causes of PE and cannot identify extracardiac metastasis.

Hypothesis/Objectives

Describe the thoracic and abdominal MDCT findings and evaluate the utility of MDCT to differentiate between neoplastic and nonneoplastic causes of PE in dogs.

Animals

Eleven client‐owned dogs with PE diagnosed by echocardiography.

Methods

Prospective observational study. Transthoracic echocardiography (TTE), 3‐view thoracic radiography, and contrast‐enhanced thoracic and abdominal MDCT images were evaluated for the presence of cardiac masses, pulmonary metastases, and abdominal masses. Histopathology in 5 dogs and survival analysis in all dogs were evaluated.

Results

A neoplastic cause was identified in 6/11 dogs and a nonneoplastic cause was identified in 5/11. Cardiac MDCT findings were consistent with TTE findings in all dogs with right atrial (5/5) and heart base masses (1/1). Pulmonary metastases were identified in 1/11 dogs by thoracic radiography and in 2/11 dogs by MDCT. MDCT identified splenic or hepatic lesions consistent with neoplasia in 6/11 and 5/11 dogs, respectively. Focal MDCT pericardial changes at the pericardiocentesis site were noted in 3/11 dogs.

Conclusions and Clinical Importance

Multidetector computed tomography did not improve the detection of cardiac masses in dogs with PE over echocardiography. The benefit of MDCT was primarily in the detection of pulmonary metastases and extracardiac lesions using a single imaging modality.     

引入青海的辽宁绒山羊的心电轴

对34只引入青海的辽宁绒山羊的心电轴进行了测定。结果发现(1)平均心电轴显著右偏，为+134．35°±76．69°；(2)心电轴左偏的山羊占14．70％，不偏的占11．77％，右偏的占73．53％。     

Transcatheter closure of aneurysmal perimembranous ventricular septal defect with the canine duct occluder in two dogs

Congenital membranous ventricular septal aneurysm has been reported in dogs and can be associated with a perimembranous ventricular septal defect (VSD). The windsock-like ventricular septal aneurysm is formed by tissue of the membranous ventricular septum and portions of the septal leaflet of the tricuspid valve. We report two dogs that underwent transcatheter closure of perimembranous VSD associated with membranous ventricular septal aneurysm using a commercial device marketed for transcatheter closure of patent ductus arteriosus, the canine duct occluder. Partial closure was achieved in the first dog with reduction in left heart dimensions documented on echocardiography both at one day and nine months after procedure. In the second dog, three-dimensional transesophageal echocardiography, cardiac computed tomography, and a three-dimensionally printed whole heart model were used to evaluate feasibility for transcatheter device closure. Complete closure of the VSD was subsequently achieved. Both cases had good short- to medium-term outcomes, no perioperative complications were observed, and both dogs are apparently healthy and receiving no cardiac medications at 34 months and 17 months after procedure. Transcatheter attenuation of perimembranous VSD with membranous ventricular septal aneurysm is clinically feasible using the canine duct occluder, and multimodal cardiac imaging allows accurate assessment and planning prior to transcatheter intervention for structural heart disease in dogs.     

Third‐Degree Atrioventricular Block and Collapse Associated with Eosinophilic Myocarditis in a Horse

Third‐degree atrioventricular block (AVB) and primary inflammatory myocarditis are uncommon findings in horses. The horse of this report presented for collapse at rest and was found to have multiple cardiac arrhythmias, most notably 3rd‐degree AVB. The horse was subsequently diagnosed with eosinophilic myocarditis on necropsy, a rare form of myocarditis not previously reported in horses. Despite extensive testing, an etiologic agent could not be identified, illustrating the difficulty in identifying a specific cause of myocarditis in horses.     

Pilot study to determine the feasibility of radiation therapy for dogs with right atrial masses and hemorrhagic pericardial effusion

Objectives

To determine the short-term safety and biologic activity of radiation therapy (RT) for presumptive cardiac hemangiosarcoma in pet dogs.