Reference intervals for simple body weight-independent measurements of right heart size and function are limited. Generate reference intervals for measurements of right heart size indexed to the long-axis aortic valve diameter (AoD) or corresponding left heart structure (right heart ratios) and describe the reproducibility of these indices. Ninety healthy adult dogs of variable body weight. Prospective study. All dogs underwent an echocardiogram performed by the same operator. Numerous linear 2-dimensional measurements of right heart size and function from different imaging planes were performed. Eight dogs underwent repeated echocardiograms by the same operator on 3 different days, and 3 different operators performed repeated echocardiograms on the same day. Reference intervals were generated using the Clinical Laboratory Standards Institute method. Reproducibility was quantitated using coefficients of variation (CVs) and reproducibility coefficients. Reference intervals for right heart ratios were generated and allow simple assessments of right heart size and function that do not require a scaling exponent or body weight table. Right heart ratios did not show clinically relevant associations with body weight. All CVs were <22.6%. In general, CVs for right heart measurements indexed to AoD were lower compared with right heart measurements indexed to the corresponding left heart structure. Reference intervals for simple body weight-independent right heart ratios are available to help detect abnormalities of right heart size and function. Reproducibility coefficients might be useful to help identify meaningful changes in right heart size during serial evaluations.

Background: Reference intervals for simple body weight-independent measurements of right heart size and function are limited. Objectives: Generate reference intervals for measurements of right heart size indexed to the long-axis aortic valve diameter (AoD) or corresponding left heart structure (right heart ratios) and describe the reproducibility of these indices. Animals: Ninety healthy adult dogs of variable body weight. Methods: Prospective study. All dogs underwent an echocardiogram performed by the same operator. Numerous linear 2-dimensional measurements of right heart size and function from different imaging planes were performed. Eight dogs underwent repeated echocardiograms by the same operator on 3 different days, and 3 different operators performed repeated echocardiograms on the same day. Reference intervals were generated using the Clinical Laboratory Standards Institute method. Reproducibility was quantitated using coefficients of variation (CVs) and reproducibility coefficients. Results: Reference intervals for right heart ratios were generated and allow simple assessments of right heart size and function that do not require a scaling exponent or body weight table. Right heart ratios did not show clinically relevant associations with body weight. All CVs were <22.6%. In general, CVs for right heart measurements indexed to AoD were lower compared with right heart measurements indexed to the corresponding left heart structure. Conclusions and Clinical Importance: Reference intervals for simple body weight-independent right heart ratios are available to help detect abnormalities of right heart size and function. Reproducibility coefficients might be useful to help identify meaningful changes in right heart size during serial evaluations.

Right atrial masses in dogs are commonly diagnosed as malignant tumors. This report describes a dog with a right atrial mass that appeared after successful electrical cardioversion of atrial fibrillation and resolved with antithrombotic treatment. A 9-year-old mastiff was presented for acute vomiting, and occasional cough of several weeks' duration. Ultrasonographic and radiographic examinations of the abdomen and chest identified mechanical ileus, as well as pleural effusion and pulmonary edema, respectively. Echocardiography indicated a dilated cardiomyopathy phenotype. During anesthetic induction for laparotomy, atrial fibrillation developed. Electrical cardioversion successfully restored sinus rhythm. An echocardiogram performed 2 weeks later disclosed a right atrial mass, which had not been apparent before cardioversion. Repeat echocardiography after 2 months of clopidogrel and enoxaparin treatment failed to detect the mass. Intra-atrial thrombus formation is possible after successful cardioversion of atrial fibrillation and should be considered as a differential diagnosis for echocardiographically detected atrial masses.

Free Access Recommended Reading June A. Boon MS, June A. Boon MS Instructor and Echocardiographer College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USASearch for more papers by this author Book Author(s):June A. Boon MS, June A. Boon MS Instructor and Echocardiographer College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, Colorado, USASearch for more papers by this author First published: 05 September 2022 https://doi.org/10.1002/9781119730200.oth AboutPDFPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShareShare a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. References Boon JA . 2011 . Veterinary Echocardiography , 2 nd ed. Wiley Blackwell . Boon JA . 2016 . Two-Dimensional and M-Mode Echocardiography for the Small Animal Practitioner , 2 nd ed. Wiley Blackwell . Keene BW , Atkins CE , Bonagura JD , et al. 2019 . ACVIM consensus guidelines for the diagnosis and treatment of myxomatous mitral valve disease in dogs . J Vet Intern Med 33 : 1127 – 1140 . Luis Fuentes V , Abbott J , Chetboul V , et al. 2020 . ACVIM consensus statement guidelines for the classification, diagnosis, and management of cardiomyopathies in cats . J Vet Intern Med 34 : 1062 – 1077 . Nagueh SF , Smiseth OA , Appleton CP , et al. 2016 . Recommendations for the evaluation of left ventricular diastolic function by echocardiography: an update from the American Society of Echocardiography and the European Association of Cardiovascular Imaging . J Am Soc Echo 29 : 277 – 314 . Reinero C , Visser L , Kellihan HB , et al. 2020 . ACVIM consensus statement guidelines for the diagnosis, classification, treatment, and monitoring of pulmonary hypertension in dogs . J Vet Intern Med 34 : 549 – 573 . Schober KE , Chetboul V . 2015 . Echocardiographic evaluation of left ventricular diastolic function in cats: hemodynamic determinants and pattern recognition . J Vet Card 317 , suppl 1 : S102 – S133 . Zoghbi WA , Adams D , Bonow RO , et al. 2017 . Recommendations for noninvasive evaluation of native valvular regurgitation. A report from the American Society of Echocardiography developed in collaboration with the Society for Cardiovascular Magnetic Resonance. ASE Guidelines and Standards . J Am Soc Echo 30 : 303 – 8371 . Doppler Echocardiography for the Small Animal Practitioner ReferencesRelatedInformation

Pulmonary hypertension (PH) is an incurable condition in humans; driven by pulmonary vascular remodeling partially mediated by epigenetic mechanisms; and leading to right ventricular hypertrophy, failure, and death. We hypothesized that targeting chromatin-modifying histone deacetylases may provide benefit. In this Brief Report we describe case comparison studies using the histone deacetylase inhibitor vorinostat (suberanilohydroxamic acid, 5 mg/kg/day for the first 5 study days) in an established model of severe neonatal bovine PH induced by 14 days of environmental hypoxia. Echocardiographic, hemodynamic, and pharmacokinetic data were obtained in hypoxia-exposed (one each, vorinostat-treated vs. untreated) and normoxic vorinostat-treated control animals ( n = 2). Echocardiography detected PH changes by day 4 and severe PH over 14 days of continued hypoxic exposure. RV dysfunction at day 4 was less severe in vorinostat-treated compared to untreated hypoxic calves. Cardioprotective effects were partially maintained following cessation of treatment through the duration of hypoxic exposure, accompanied by hemodynamic evidence suggestive of reduced pulmonary vascular stiffening, and modulated expression of HDAC1 protein and genes involved in RV and pulmonary vascular remodeling and pathological RV hypertrophy. Control calves did not develop PH, nor show adverse cardiac or clinical effects. These results provide novel translation of epigenetic-directed therapy to a large animal severe PH model that recapitulates important features of human disease.

BACKGROUND:Right ventricle failure (RVF) is associated with serious cardiac and pulmonary diseases that contribute significantly to the morbidity and mortality of patients. Currently, the mechanisms of RVF are not fully understood and it is partly due to the lack of large animal models in adult RVF. In this study, we aim to establish a model of RVF in adult ovine and examine the structure and function relations in the RV.METHODS:RV pressure overload was induced in adult male sheep by revised pulmonary artery constriction (PAC). Briefly, an adjustable hydraulic occluder was placed around the main pulmonary artery trunk. Then, repeated saline injection was performed at weeks 0, 1, and 4, where the amount of saline was determined in an animal-specific manner. Healthy, age-matched male sheep were used as additional controls. Echocardiography was performed bi-weekly and on week 11 post-PAC, hemodynamic and biological measurements were obtained.RESULTS:This PAC methodology resulted in a marked increase in RV systolic pressure and decreases in stroke volume and tricuspid annular plane systolic excursion, indicating signs of RVF. Significant increases in RV chamber size, wall thickness, and Fulton's index were observed. Cardiomyocyte hypertrophy and collagen accumulation (particularly type III collagen) were evident, and these structural changes were correlated with RV dysfunction.CONCLUSION:In summary, the animal-specific, repeated PAC provided a robust approach to induce adult RVF, and this ovine model will offer a useful tool to study the progression and treatment of adult RVF that is translatable to human diseases.

Two-dimensional ultrasound sends out multiple side by side sound waves, which generate a sector or pie-shaped image of the heart. The sound beams leave the transducer as a sheet of sound and are directed though any plane of the heart. Pulsed-wave Doppler is specifically used when the interest in flow is specific to a particular locale. Color flow Doppler provides instant gratification. High-velocity and turbulent blood flow is immediately identified. Pericardial effusion is identified as an echo-free space between the ventricular walls and the pericardial sac. Recent studies in humans have shown that echocardiographic detection of right ventricular collapse was much more specific for the diagnosis of cardiac tamponade than using the echocardiographic feature of right atrial collapse alone. The mitral valve is the most common site of infection in dogs, followed by aortic, pulmonic, and tricuspid valves.

Right ventricle failure (RVF) contributes significantly to the morbidity and mortality in pulmonary hypertension (PH).The mechanical behavior of the RV is considered fundamental to its physiological function; however, the link between RV tissue biomechanics and organ function remains a key knowledge gap.We hypothesize that the RV passive elasticity is correlated with its in vivo function.In this study, we examined the relationships between the tissue mechanics and physiological function of the RV in healthy and PH sheep using a revised ovine model of pulmonary artery constriction.In vivo RV function was examined by echocardiography and hemodynamic measurement, and the RV passive elasticity was measured by ex vivo equibiaxial mechanical tests.We observed that the RV longitudinal stiffness was significantly increased and thus the anisotropic property was altered in PH sheep.This elasticity was significantly correlated with the long axis end-diastolic or end-systolic diameter/area.We further observed that in the outflow tract (longitudinal) direction, there were trends of correlations between the low-strain elastic modulus (EM) and the acceleration time, as well as between the high-strain EM and the deceleration time.These findings strongly indicate the critical role of RV passive mechanical properties in the organ function.

Despite the term “heartworm disease” Dirofilaria immitis infection in dogs should be considered a pulmonary arterial disease that might only involve the right heart structures in its late stage. Chronic infection by adult heartworms in dogs results in proliferative endoarteritis leading to progressively increasing pulmonary artery pressure due to reduced elasticity. Elasticity allows the pulmonary arteries to stretch in response to each pulse and helps maintain a relatively constant pressure in the arteries despite the pulsating nature of the blood flow. Pulmonary artery distensibility for both acute and chronic pulmonary hypertension has been investigated in humans using MRI and has been correlated with the severity of hypertension and its outcome and treatment response. The aim of the present study was to investigate whether echocardiographic measurement of the percentage change in diameter of the right pulmonary artery in systole and diastole (distensibility) may be of value in assessing the presence and severity of pulmonary hypertension in heartworm-infected dogs. The Right Pulmonary Artery Distensibility Index (RPAD Index) (which is calculated as the difference in diameter of the right pulmonary artery in systole and diastole) was calculated in healthy and naturally infected heartworm-positive dogs. The right pulmonary artery was chosen because it is usually affected earlier and to a greater degree. Data were obtained from healthy heartworm-free dogs without any clinical, radiographic, or echocardiographic signs of pulmonary hypertension; naturally infected heartworm-positive dogs in different stages of the disease in which pulmonary pressure could be measured by Doppler echocardiography (using tricuspid and or pulmonary regurgitation velocity and pressure gradient); and naturally infected heartworm-positive dogs in different stages of the disease (with or without tricuspid and or pulmonary regurgitation) in which the pulmonary pressure was measured invasively and noninvasively if possible. Results of these evaluations indicated that RPAD Index is a valuable method for early detection of the presence and severity of pulmonary hypertension in heartworm-infected dogs even in the absence of regurgitant jets for Doppler evaluation and that there is a strong correlation between the RPAD Index and the level of pulmonary hypertension.

OBJECTIVES:The objectives of this study were to obtain standard echocardiographic measurements from healthy Border Collies and to compare these measurements to those previously reported for a general population of dogs. ANIMALS:Standard echocardiographic data were obtained from twenty apparently healthy Border Collie dogs. These data (n = 20) were compared to data obtained from a general population of healthy dogs (n = 69). METHODS:Border Collies were deemed healthy based on normal history, physical examination, complete blood count, serum biochemical profile, electrocardiogram, and blood pressure, with no evidence of congenital or acquired heart disease on echocardiographic examination. Standard two dimensional, M-mode, and Doppler echocardiographic measurements were obtained and normal ranges determined. The data were compared to data previously obtained at our hospital from a general population of normal dogs. RESULTS:Two dimensional, M-mode, and Doppler reference ranges for healthy Border Collies are presented in tabular form. Comparison of the weight adjusted M-mode echocardiographic means from Border Collies to those from the general population of dogs showed Border Collies to have larger left ventricular systolic and diastolic dimensions, smaller interventricular septal thickness, and lower fractional shortening. CONCLUSIONS:There are differences in some echocardiographic parameters between healthy Border Collies and the general dog population, and the echocardiographic reference ranges provided in this study should be used as breed specific reference values for Border Collies.

Cardiomiopatia restritiva e uma disfuncao ventricular diastolica caracterizada por restricao ao preenchimento ventricular e reducao do volume diastolico dos ventriculos, com significativa dilatacao atrial e geralmente com indices de funcao sistolica e espessura de parede ventricular inalterados. Tal reducao na complacencia ventricular diastolica ocorre devido a fibrose miocardica ou subendocardica, ou por doencas infiltrativas. Essa forma de cardiomiopatia e particularmente diagnosticada em felinos, causando sinais de insuficiencia cardiaca congestiva (ICC) esquerda ou tromboembolismo. Foi atendida, no Servico de Cardiologia do Hospital Veterinario da Universidade Paulista, uma cadela da raca fox paulistinha, com tres anos de idade, cujo proprietario relatava aumento de volume abdominal, negando demais manifestacoes clinicas. Ao exame fisico, auscultou-se ritmo cardiaco regular com sopro sistolico grau III/VI em focos mitral e tricuspide e denotou-se ascite com conteudo serossanguineo. No hemograma verificou-se leucocitose por neutrofilia, e as funcoes renal e hepatica estavam inalteradas. No eletrocardiograma observou-se taquicardia sinusal com caracteristicas de aumento biatrial. Cardiomegalia foi observada ao exame radiografico de torax, nao havendo alteracoes pulmonares. No ecodopplercardiograma, constatou-se importante aumento biatrial e insuficiencia valvar mitral e tricuspide, disfuncao diastolica biventricular com padrao restritivo e disfuncao sistolica de ventriculo direito, com dimensoes preservadas das câmaras ventriculares. Ministrou-se terapia com furosemida, espironolactona, benazepril e diltiazem, ocorrendo obito apos oito meses. Durante esse periodo, o animal apresentou diversos episodios de ascite e, ao final, cursou com efusao pleural e sinais de baixo debito cardiaco. A apresentacao inusitada de cardiomiopatia restritiva em um animal da especie canina com predominância de sinais clinicos de ICC direita justifica o presente relato. Normal 0 21 false false false PT-BR X-NONE X-NONE

OBJECTIVE:To report the outcome of partial external mitral annuloplasty in dogs with congestive heart failure (CHF) due to mitral regurgitation caused by myxomatous mitral valve degeneration (MMVD).ANIMALS, MATERIALS AND METHODS:Nine client-owned dogs with CHF due to mitral regurgitation caused by MMVD. Surgery consisted of a double row of pledget-butressed continuous suture lines placed into the left ventricle parallel and just ventral to the atrioventricular groove between the subsinuosal branch of the left circumflex coronary artery and the paraconal branch of the left coronary artery.RESULTS:Two dogs died during surgery because of severe hemorrhage. Two dogs died 12 and 36 h after surgery because of acute myocardial infarction. Three dogs were euthanized 2 and 4 weeks after surgery because of progression of CHF, 1 was euthanized 30 days after surgery for non-cardiac disease, and 1 survived for 48 months. In the 5 dogs that survived to discharge there was no significant change in the left atrium to aortic ratio with surgery (3.6 ± 0.56 before surgery; 3.1 ± 0.4 after surgery; p = 0.182), and no significant change in mitral regurgitant fraction in 4 dogs in which this measurement was made (78.7 ± 2.0% before surgery; 68.7 ± 7.5% after surgery; p = 0.09).CONCLUSIONS:Partial external mitral annuloplasty in dogs with CHF due to MMVD was associated with high perioperative mortality and most dogs that survived to discharge failed to show clinically relevant palliation from this procedure. Consequently, partial external mitral annuloplasty is not a viable option for dogs with mitral regurgitation due to MMVD that has progressed to the stage of CHF.

OBJECTIVE:To describe the surgical technique and report outcome of dogs undergoing bioprosthesis valve replacement for severe tricuspid regurgitation (TR) secondary to congenital tricuspid valve dysplasia (TVD).ANIMALS, MATERIALS AND METHODS:Twelve client-owned dogs (19-43 kg) with TVD underwent tricuspid valve replacement with a bovine pericardial or porcine aortic bioprosthesis with the aid of cardiopulmonary bypass. Anticoagulation with warfarin was maintained for 3 months after surgery and then discontinued.RESULTS:Ten of 12 (83.3%) dogs survived surgery and were discharged from the hospital. Seven dogs were alive with complete resolution of TR for a median period of 48 months (range 1-66 months) after surgery. Two dogs underwent euthanasia because of bioprosthesis failure due to inflammatory pannus at 10 and 13 months after surgery. Two dogs experienced valve thrombosis that was resolved by tissue plasminogen activator. One dog developed suspected endocarditis after surgery that was resolved with antibiotics. Serious cardiac complications included atrial fibrillation and flutter, right-to-left shunt through an uncorrected patent foramen ovale, complete atrioventricular block, and sudden cardiac arrest. Postoperative atrial fibrillation or flutter did not occur in 7 dogs treated prophylactically with oral amiodarone before surgery.CONCLUSIONS:Curative intermediate-term outcomes are possible in dogs undergoing open tricuspid valve replacement with a bioprosthesis. Prosthesis-related complications include inflammatory pannus, thrombosis, and endocarditis. Postoperative atrial fibrillation or flutter can be reduced or prevented by prophylactic preoperative treatment with amiodarone. Several identified complications are avoidable or can be reduced with increased awareness and experience with these techniques.

Univentricular atrioventricular (AV) connections are rare and complex congenital cardiac anomalies in which both AV valves communicate into a large, common (single) receiving chamber. The common chamber can be of left, right, or mixed ventricular morphology. Although well documented in people, reports of the double-inlet ventricle malformation are rare in the veterinary literature. This report provides description of an Arabian horse with a double-inlet univentricular connection of left ventricular type, a hypoplastic subpulmonary right ventricle, two muscular ventricular septal defects, and a stenotic mitral valve. Transthoracic Doppler echocardiography enabled antemortem diagnosis, and provided an assessment of intracardiac hemodynamics. The findings indicate that Doppler echocardiography is a useful, noninvasive tool for evaluating equine patients with congenital univentricular AV connections, such as a double-inlet left ventricle.

BACKGROUND:Age and heart rate have effects on myocardial velocities as assessed by color tissue Doppler imaging (TDI) in people. A similar phenomenon has been identified when left ventricular velocities are assessed in cats. To date, the effects of age and heart rate on tricuspid annular velocities of cats have not been assessed.OBJECTIVES:This study was designed to determine the relationships between age and heart rate and tricuspid annular velocities in cats as assessed by 2-dimensional (2D) color TDI.ANIMALS:Fifty healthy nonsedated cats with age range from 3 months to 19 years old were studied.METHODS:Tricuspid annular velocities were obtained with 2D color TDI. Effects of age and heart rate on tricuspid annular velocities were evaluated by simple linear regression. The strength of the linear relationship was determined by using coefficient of determination (R2).RESULTS:A significant weak negative relationship was found between age and peak early diastolic annular velocity (E'; R2 = 0.135, P = .018). No significant relationships between age and right ventricular (RV) systolic TDI values were found. Diastolic and systolic TDI parameters were not affected by heart rate with the exception of deceleration rate of early diastolic motion (DR; R2 = 0.100, P = .025).CONCLUSIONS AND CLINICAL IMPORTANCE:Age and heart rate have minimal effects on tricuspid annular velocities. The present study provides reference ranges for tricuspid annular velocities in healthy cats and information for assessing the clinical utility of color TDI for evaluation of RV function in cats.

Case Description-A 5-year-old male German Shepherd Dog was evaluated because of a 5-month history of progressive lethargy, weight loss, and heart failure.Clinical Findings-On physical examination, bounding femoral pulses and systolic and diastolic murmurs were detected. Echocardiography revealed severe aortic valve insufficiency (AVI) and a large vegetative lesion on the aortic valve consistent with aortic valve endocarditis. The AVI velocity profile half-time was 130 milliseconds; the calculated peak systolic pressure gradient across the aortic valve was 64 mm Hg. Left ventricular diameter during diastole was 63.6 mm (predicted range, 40.2 to 42 mm) and during systole was 42.9 mm (predicted range, 25.4 to 27 mm). Systolic, diastolic, and mean arterial blood pressures were 120, 43, and 65 mm Hg, respectively.Treatment and Outcome-To palliate severe AVI, the descending aorta was occluded (duration, 16.75 minutes) and heterotopic implantation of a porcine bioprosthetic heart valve in that vessel was performed. After surgery, systolic, diastolic, and mean arterial blood pressures were 115, 30, and 61 mm Hg, respectively, in the forelimb and 110, 62, and 77 mm Hg, respectively, in the hind limb. Within 6 months, the AVI velocity profile half-time had increased to 210 milliseconds, indicating diminished severity of AVI. After 24 months, the dog was able to engage in vigorous exercise; no pulmonary edema had developed since surgery.Clinical Relevance-Heterotopic bioprosthetic heart valve implantation into the descending aorta during brief aortic occlusion appears feasible in dogs and may provide substantial palliation for dogs with severe AVI.