Echocardiography is a diagnostic imaging technique used to assess the heart's structure and function in horses. It utilizes ultrasound waves to create detailed images of the heart, allowing veterinarians to evaluate cardiac anatomy, blood flow, and heart motion. Echocardiography is instrumental in diagnosing various cardiac conditions, such as valvular disorders, congenital heart defects, and myocardial diseases in equine patients. The procedure provides valuable information on heart size, wall thickness, and chamber dimensions. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and clinical implications of echocardiography in equine cardiology.
Vernemmen I, Van Steenkiste G, Buschmann E, Cornelis K, Schauvliege S, Ibrahim L, Decloedt A, van Loon G.Radiofrequency ablation has been successfully applied to treat right atrial arrhythmias in horses. Ablation of left-sided arrhythmias requires a retrograde transarterial approach which is complicated. In human medicine, the left atrium is accessed through transseptal puncture (TSP) of the fossa ovalis (FO) using a caudal approach via the femoral vein. Objective: To develop a zero fluoroscopy TSP technique for horses using a jugular vein (cranial) and transhepatic (caudal) approach. Methods: In vivo experimental study. Methods: Transseptal puncture was performed in 18 horses admitted for euthan...
Piotrowski IL, Junge HK, Schwarzwald CC.Mitral and aortic valve insufficiencies have been commonly reported in horses. The objective of this study was to establish the use of acoustic cardiography (Audicor®) in horses with aortic (AI) or mitral valve insufficiency (MI). A total of 17 healthy horses, 18 horses with AI, and 28 horses with MI were prospectively included. None of the horses was in heart failure. Echocardiography and Audicor® analyses were conducted. Electromechanical activating time (EMAT), rate-corrected EMATc, left ventricular systolic time (LVST), rate-corrected LVSTc, and intensity and persistence of the third and...
Naseri A, Akyuz E, Turgut K, Guzelbektes H, Sen I.The term "sepsis-induced cardiomyopathy" (SIC) is used to describe transient cardiac dysfunction in septic patients. However, there is no universally accepted definition of SIC; a reduction in left ventricular ejection fraction (LVEF) is often used. In addition to systolic dysfunction, diastolic dysfunction is now recognized as an essential component of SIC. It can be emphasized that previous animal experiments played an essential role in revealing SIC and hemodynamic instability in sepsis and septic shock. The diagnostic and prognostic capabilities of echocardiography for the assessment of SI...
Chompoosan C, Pongthaisong P, Kenchaiwong W, Pontaema T, Lerdweeraphon W.Pregnancy affects maternal hemodynamics. The changes in autonomic nervous system activity for hemodynamics adaptation in pregnant horses are still unclear. Thus, this study aimed to examine the effect of pregnancy on electrocardiographic, vasovagal tonus index, and echocardiographic variables in horses. Unassigned: A total of 23 Thai native crossbred mares without any cardiac abnormalities were included in this study. The animals were assigned into two groups, a non-pregnant mare group (n =12) and a pregnant mare group (n = 11). Electrocardiogram recordings (paper speed = 25 mm/s and calibrati...
Heun F, Niebuhr T, Gutierrez Bautista A, Wiedmann F, Verhaar N, Kästner S, Feige K, Schmidt C.A two-year-old donkey presented with recurrent syncope. Electrocardiography revealed periods without any atrioventricular conduction and without any ventricular escape rhythm with a duration of up to one minute. Finally, atrioventricular conduction resumed spontaneously with a preceding ventricular escape beat. Laboratory tests and echocardiography identified no reversible cause. The diagnosis of a paroxysmal atrioventricular block (PAVB) was made. Therefore, a single-chamber cardiac pacemaker was implanted under general anesthesia. The device was programmed in the VVI mode to prevent further ...
Kis J, Rózsa L, Husvéth F, Mezőszentgyörgyi D, Kovács S, Bakos Z, Zsolnai A, Anton I.The g.66493737C/T polymorphism of the myostatin gene (MSTN) majorly influences muscle fiber composition and best race distance of Thoroughbreds. Thus, a better understanding of this process may lead to superior genetic exploitation for maximizing Thoroughbred athletic potential. Our objective is to investigate whether myostatin genotypes are associated with muscular development and cardiac variables of Thoroughbreds. Echocardiography and muscular ultrasonography were performed on three groups having C/C, C/T, and T/T genotypes, respectively. Each group consisted of 22 animals. Homogeneity of v...
Carstensen H, Nissen SD, Saljic A, Hesselkilde EM, van Hunnik A, Hohl M, Sattler SM, Fløgstad C, Hopster-Iversen C, Verheule S, Böhm M, Schotten U....Atrial fibrillation (AF) is more prevalent in athletes, and currently, the mechanisms are not fully understood. Atrial fibrillation inducibility and stability was investigated in trained and untrained Standardbred racehorses. The horses underwent echocardiography for evaluation of atrial size. High-density mapping during AF was performed, and the presence of structural remodeling, as well as the expression of inflammatory and pro-inflammatory markers in the atria, was studied. Atrial fibrillation sustained significantly longer after tachypacing in the trained horses, whereas no difference in A...
Cruz-Aleixo AS, de Oliveira KC, de Oliveira Ferreira LV, Cedeo Quevedo DA, Cruz RKS, Tsunemi MH, Chiacchio SB, Lourenço MLG.Clinical, electrocardiographic and echocardiographic parameters in Pega donkeys are scarce in the literature; hence, this study was performed to describe the echocardiographic and electrocardiographic measurements in Pega breed donkeys. The objectives of this study were to describe and illustrate the clinical, electrocardiographic, and echocardiographic parameters in Pega donkeys used for reproduction. Fifty Pega breed donkeys were evaluated, with an average age of 3.4 years and with 20 males and 30 females. In each animal, the electrocardiographic examination at rest was performed using the T...
Marzok M, Kandeel M, Babiker H, Alkhodair KM, Farag A, Ibrahim H, El-Ashker M, Alghuwainem Y, El-Khodery S.The purpose of this study was to provide a systematic meta-analysis on echocardiographic measurements in normal Thoroughbred and Standardbred horses. The current systematic meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA). All the available published papers on the reference values of echocardiographic assessment via M-mode echocardiography were searched, and fifteen studies were finally selected for analysis. In both fixed and random effect, the confidence interval (CI) for the interventricular septum (IVS) was 2.8-3.1 and 4.7-7.5; for the ...
Nissen SD, Saljic A, Kjeldsen ST, Jespersen T, Hopster-Iversen C, Buhl R.Second-degree atrioventricular (AV) block is the most common cardiac arrhythmia in horses, affecting 40-90% depending on breed. Usually, the AV blocks occur while the horses are resting and disappear upon exercise and are, therefore, considered to be uneventful for horses. However, if the AV blocks occur frequently, this may result in syncope and collapse. Identifying the cause of second-degree AV block is difficult and often subscribed to high vagal tone. In this report, we present an eight-year-old Quarter horse with a high burden of second-degree AV blocks and multiple collapses. The clinic...
Vitale V, Vezzosi T, Di Franco C, Briganti A, Tognetti R, Conte G, Bucchioni E, Sgorbini M.For the echocardiographic examination horses should not be sedated unless absolutely necessary because this alters cardiac dimensions and indices of function. However, some horses do not tolerate the echocardiographic procedure and require sedation to conduct the examination safely and obtain good quality images. The objective of this study was to evaluate whether the concurrent infusion of dobutamine in horses sedated with romifidine counteracts the cardiovascular changes observed with sedation alone. Twelve healthy untrained Standardbred mares were used. Three echocardiographic examinations ...
Freitas MS, Pereira AHB, Pereira GO, Menezes IS, Lucena AR, Almeida CRF, Pereira EG, Santos LA, Tozin LRS, Alves FM, Macedo AL, Silva DB, Ubiali DG.Poisoning by avocado (Persea americana) has been confirmed in sheep, goats, dogs, rabbits and ostriches. The clinical signs and lesions are attributed to the acetogenin, persin. Little is known regarding the epidemiology, clinical signs, lesions and therapy caused by acetogenin-induced heart damage. During the two-year study, we investigated a horse farm with six horses that often fed themselves with P. americana leaves or mature fruit pulp and skin on the ground. Two horses died, and one underwent necropsy, histopathology, and immunohistochemistry using the anti-cardiac troponin C (cTnC). Gro...
Khalesi H, Sakha M, Veshkini A, Rezakhani A.Heart murmurs and valvular regurgitation are common in horses and often have no effect on their performance. However, when structural changes occur in the heart size, they can affect performance adversely. This study aimed to examine the correlation between cardiac valves disease and poor performance in athletic horses. A total of 300 athletic Thoroughbred and mix-breed horses including 164 mares and 136 stallions, with a history of poor performance, were selected. Horses with cardiac murmurs were identified and further cardiac examination including precise auscultation, base-apex electrocardi...
De Lange L, Vernemmen I, van Loon G, Decloedt A.The ductus arteriosus (DA) and foramen ovale (FO), including the septum primum (SP) and septum secundum (SS), are important structures in fetal circulation and are unexplored in neonatal equids. The objective of this study is to describe echocardiographic characteristics in a hospital-based population of neonatal foals. On days 2, 5 and 10 after parturition, cardiac ultrasound was performed, and clinical data were collected in healthy and diseased Warmblood foals. Fifty healthy ( = 15) and diseased ( = 35) Warmblood foals were examined. A left-sided and right-sided holosystolic murmur was audi...
Ter Woort F, Stefanovski D, Reef VB.Hyperthyroidism is a predisposing factor for atrial fibrillation (AF) in humans. The relationship between high thyroid hormone (TH) and AF in horses has not been evaluated. Objective: The aim of this study is to identify whether (1) high TH concentrations were present in horses with AF, (2) other cardiovascular effects were observed in horses with high TH and AF, and (3) TH status affected recurrence rate. Methods: Twenty-three horses presented with naturally occurring AF. Methods: Prospective case-control clinical study. Thyroid hormone concentration was measured in horses presenting with AF....
Williams NJ, Furr M, Navas de Solis C, Campolo A, Davis M, Lacombe VA.Metabolic syndrome in humans is commonly associated with cardiovascular dysfunction, including atrial fibrillation and left ventricular diastolic dysfunction. Although many differences exist between human and equine metabolic syndrome, both of these conditions share some degree of insulin resistance. The aims of this pilot study were to investigate the relationship between insulin sensitivity and cardiac function. Seven horses (five mares, two geldings, aged 17.2 ± 4.2 years, weight 524 ± 73 kg) underwent insulin-modified frequently sampled intravenous glucose tolerance testing to determine ...
Eberhardt C, Schwarzwald CC.Focused cardiac ultrasound examination (FoCUS) is rapidly emerging for point-of-care cardiac assessment using hand-carried ultrasound (HCU) devices. A specific FoCUS protocol for horses and adequate training guidelines currently are not available. Objective: To gain knowledge about the training necessary to become proficient in performing FoCUS using a HCU device. Methods: Three healthy Warmblood horses were used for practical training of veterinarians and veterinary students in equine focused cardiac ultrasound (eFoCUS). Methods: Prospective educational study. An eFoCUS protocol and 1-day tra...
Vernemmen I, Paulussen E, Dauvillier J, Decloedt A, van Loon G.This case report describes the 2-dimensional transthoracic (2D-TTE), 3-dimensional transthoracic (3D-TTE) and intracardiac echocardiographic (ICE) characterization of the fossa ovalis region in 2 horses. The first case was presented for poor performance and showed an anechoic zone in the interatrial septum on 2D-TTE. Based on 3D-TTE a deepened fossa ovalis could be identified and using ICE the presence of an interatrial shunt could be excluded. The second case was referred for a cardiac murmur and the presence of turbulent flow in and around the interatrial septum on 2D-TTE color flow Doppler....
Boutet BG, Gordon SG, De Solis CN, Lepiz MA, Saunders AB, Wesselowski S.Intracardiac echocardiography (ICE) is a method of obtaining echocardiographic images with a steerable ultrasound catheter placed within the heart via a venous or arterial approach. The objectives of this study were to assess the feasibility of a 5-10 MHz, 8 French, 90 cm ICE catheter to evaluate cardiac structures and function in standing, sedated horses, and describe standard views in this species. Methods: Ten apparently healthy horses weighing 458.1-618.2 kg from a university teaching herd. Methods: Each horse had a physical examination, transthoracic echocardiography, and ICE performe...
Alberti E, Stucchi L, Lo Feudo CM, Ferrucci F, Zucca E.Pulmonary artery stiffness (PAS) is an index of pulmonary artery elasticity that permits to evaluate the pulmonary vascular bed in humans. It can early detect an increase in pulmonary artery stiffness as a consequence of remodeling of the vessel wall caused by chronic pulmonary and congenital heart diseases. This remodeling can occur also in horses with chronic respiratory diseases. Thus, PAS could be a useful echocardiographic parameter also in horses. However, in literature, there are no studies regarding PAS in horses. The aim of this study is to evaluate the feasibility of PAS in horses. F...
Vernemmen I, Van Steenkiste G, Dufourni A, Decloedt A, van Loon G.Transvenous electrical cardioversion (TVEC) is 1 of the main treatment options for atrial fibrillation (AF) in horses. Large-scale studies on factors affecting success and prognosis have primarily been performed in Standardbred populations. Objective: To determine factors affecting cardioversion success, cardioversion difficulty and recurrence in a predominant Warmblood study sample. Methods: TVEC records of 199 horses. Methods: Retrospective study of TVEC procedures of horses admitted for AF without severe echocardiographic abnormalities. Horse and procedural factors for success and cumulativ...
Xue C, Cavanaugh SM.Reports of ante-mortem diagnosis of cardiovascular diseases in donkeys (Equus asinus) are rare. This case report describes the echocardiographic findings of suspected mitral valve dysplasia in a 3-year-old Nevisian donkey jenny presented for evaluation of a grade III/VI left-sided systolic murmur. Pertinent findings on transthoracic echocardiography included double mitral regurgitant jets and a bridge of tissue between the septal and mural mitral leaflets. Based upon the mild degree of cardiac remodeling and absence of clinical signs, therapeutic intervention was deemed unnecessary, and the je...
Deacon LJ, Navas de Solis C, Richardson DW, Polkes A, Reef VB.• An ACF developed in a hospitalized horse following orthopedic surgery. • Spontaneous closure of the ACF occurred 6 weeks after initial diagnosis. • Echocardiography is the primary imaging modality to confirm the presence of ACF in equids. [Figure: see text]
Hövener J, Pokar J, Merle R, Gehlen H.Heart murmurs are detected frequently when auscultating horses and certain murmurs can usually be linked to specific valvular regurgitations. Limited information exists about the accuracy of these broad rules in warmblood horses and the influence of grade of the regurgitation and dimensional changes on murmur intensity. This study aims to clarify the accuracy of cardiac auscultation in warmblood horses and the influence of the grade of regurgitation and dimensional changes on the loudness of the murmur. In this retrospective study, 822 warmblood horses presented for cardiac examination in a la...
Gehlen H, Fisch J, Merle R, Trachsel DS.Pituitary pars intermedia dysfunction (PPID), a neurodegenerative disease leading to reduced dopamine production, is a common disease in aged horses. The treatment is based on administration of the dopamine agonist pergolide. This drug has been related to valvular fibrosis in humans, but the cardiovascular effect of this drug has not yet been investigated in horses. Objective: To determine whether pergolide induces valvular disease in horses or affects the cardiac function. Methods: Standard, tissue Doppler (TDE) and two-dimensional speckle tracking (STE) echocardiography were performed in hor...
D' Fonseca NMM, Beukers M, Wijnberg ID, Navas de Solis C, de Ruijter-Villani M, van Doorn DA, Stout TAE, Roelfsema E.Changes in cardiovascular parameters, including blood pressure (BP) and cardiac anatomical dimensions, are an inconsistent feature of the equine metabolic syndrome. The order in which these changes arise is unknown. Objective: Determine the order in which EMS-associated changes in cardiovascular parameters arise. Methods: Twenty Shetland pony mares. Methods: High-energy (HE) diet mares were fed 200% of net energy requirements for 1 (n = 3) or 2 (n = 7) consecutive diet-years, with 17 weeks of hay-only between years. Noninvasive BP measurements and echocardiograms were performed during bo...
Junge HK, Glaus T, Matos JN, Meira C, Schwarz A, Hoey S, Dennler M, Schwarzwald CC, Mitchell KJ.In a 1-day old filly with a loud heart murmur, transthoracic echocardiography revealed right ventricular hypertrophy associated with severe pulmonary valvular stenosis and a transvalvular pressure gradient (between right ventricle and pulmonary artery) of 125 mmHg. Computed tomographic angiography confirmed the finding, with no evidence of other relevant concurrent abnormalities. Balloon valvuloplasty was performed using a single balloon technique. The foal recovered well from anaesthesia. Following the procedure, the right ventricle-pulmonary artery transvalvular gradient decreased to 38 mm...
Eberhardt C, Schwarzwald CC.In horses, persistent atrial dysfunction is a prognostic indicator of recurrence of atrial fibrillation (AF). The objective of this study was to quantify left atrial (LA) contractile function in Warmblood horses after successful cardioversion of AF to sinus rhythm, using standard two-dimensional echocardiography (2DE) and two-dimensional speckle tracking (2DST) analyses, and to provide proof-of-concept for use of 2DST to detect LA contractile dysfunction in horses. Methods: Nineteen Warmblood horses with AF and successful transvenous electrical cardioversion (TVEC) or medical cardioversion usi...
De Lange L, Vera L, Decloedt A, Van Steenkiste G, Vernemmen I, van Loon G.Ventricular septal defects (VSDs) are the most common congenital cardiac defect in horses. Objective: To identify prevalence, age, breed, and sex distribution of VSD and to describe associated clinical and ultrasonographic findings. Methods: Hospital-based population of 21 136 horses presented to the equine internal medicine department. Methods: Medical records over a 12-year period were reviewed for VSD confirmed by ultrasonography. Age, breed, sex, sport discipline, murmur, clinical signs, outcome, VSD type, VSD size, shunt velocity, cardiac dimensions, concomitant cardiac anomalies, and v...
Brown DJ, Rush JE, MacGregor J, Ross JN, Brewer B, Rand WM.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 inhe...
Schwarzwald CC, Schober KE, Bonagura JD.To assess the feasibility, describe the techniques, and determine the reliability of transthoracic echocardiography for characterization of left atrial (LA) size and LA mechanical function in horses. Methods: 6 healthy adult horses. Methods: Repeated echocardiographic examinations were performed independently by 2 observers in standing, unsedated horses by use of 2-dimensional echocardiography, pulsed-wave flow Doppler, and tissue Doppler imaging (TDI) techniques. Test reliability was determined by estimating measurement variability, within-day interobserver variability, and between-day inter-...
Richard EA, Fortier GD, Pitel PH, Dupuis MC, Valette JP, Art T, Denoix JM, Lekeux PM, Erck EV.The objectives of this study were to determine the prevalence of sub-clinical diseases in poorly-performing Standardbred horses, compare their physiological response to exercise with control horses, and identify predictive parameters of poor-performance. Fifty horses underwent thorough clinical and ancillary examinations, including haematological and biochemical evaluation, Doppler echocardiography, standardised exercise tests (SETs) on both treadmill and racetrack, treadmill video-endoscopy and collection of respiratory fluids. Most of the poorly-performing horses exhibited many concomitant d...
Long KJ, Bonagura JD, Darke PG.Eighteen echocardiographic images useful for diagnostic imaging, M-mode echocardiography, and Doppler echocardiography of the equine heart were standardised by relating the position of the axial beam to various intracardiac landmarks. The transducer orientation required for each image was recorded in 14 adult horses by describing the degree of sector rotation and the orientation of the axial beam relative to the thorax. Repeatable images could be obtained within narrow limits of angulation and rotation for 14 of the 18 standardised images evaluated. Twenty-seven National Hunt horses were subse...
Schwarzwald CC, Schober KE, Bonagura JD.Noninvasive assessment of left ventricular (LV) function is incompletely studied in horses. Objective: The goals of this study were to investigate the feasibility, techniques, and reliability of tissue Doppler imaging (TDI) for characterization of LV radial wall motion in healthy horses. Methods: Three Standardbreds, 3 Thoroughbreds; age 8-14 years; body weight 517-606 kg. Methods: Repeated echocardiographic examinations were performed by 2 observers in unsedated horses using TDI. Test reliability was determined by estimating measurement variability, within-day interobserver variability, and b...
Buhl R, Ersbøll AK, Eriksen L, Koch J.To evaluate changes over time in echocardiographic measurements in young Standardbred racehorses undergoing training and racing and determine whether there was any relationship between cardiac dimensions and racing performance. Methods: Longitudinal observational study. Methods: 103 horses. Methods: 2-dimensional and M-mode echocardiography was performed 4 times at 6-month intervals. Results: Significant cardiac enlargement took place during the study period as indicated by increases in left ventricular internal diameter in diastole (LVIDd), estimated left ventricular muscle mass (LV mass), an...
Buhl R, Ersbøll AK.To assess whether physical training induces cardiac hypertrophy and valvular regurgitation in maturing Standardbred trotters and to establish a prediction model for the size of the left ventricle. Methods: Longitudinal observational study. Methods: 53 Standardbred trotters. Methods: Each horse underwent 2-D, M-mode, and color flow Doppler echocardiography at 5.5 years of age; previously, each horse had been examined at 2, 2.5, 3, and 3.5 (time of maturity) years of age. Horses were or were not in training or racing for variable periods during the entire assessment period; data for a given hors...
Schwarzwald CC.This article provides an overview on the principles of transthoracic echocardiography in horses. Indications for echocardiography, equipment, and technical considerations are discussed and a systematic approach for a complete echocardiographic examination in horses is described. Methods for assessment of chamber dimensions, allometric scaling of measurements, assessment of systolic and diastolic ventricular function, assessment of atrial function, hemodynamic assessment, and evaluation of valvular regurgitation are explained, focusing on traditional 2-dimensional (2D), motion-mode, and Doppler...
Schefer KD, Bitschnau C, Weishaupt MA, Schwarzwald CC.Stress echocardiography is used to diagnose myocardial dysfunction in horses, but current methods are not well standardized. The influence of heart rate (HR) on measurements is largely unknown. Objective: To investigate the use of 2-dimensional echocardiography (2DE), anatomical M-mode (AMM), tissue Doppler imaging (TDI), and 2D speckle tracking (2DST) at rest and after exercise for quantification of regional and global left-ventricular (LV) function. Methods: Five athletic Warmblood horses; 11.6+/-3.6 years; 529+/-48 kg. Methods: Prospective study. Three separate echocardiographic examination...
Slater JD, Herrtage ME.Echocardiographic examinations were performed on 41 clinically normal small ponies, large ponies and horses. Using standardised two-dimensional (2-D) echocardiographic images to guide M-mode studies, the interventricular septal thickness, left ventricular internal dimension and left ventricular wall in systole and diastole, and aortic diameter in diastole were measured. Normal values for these echocardiographic dimensions were obtained across a wide range of bodyweights. Although there was a trend for echocardiographic dimensions to increase with bodyweight across the whole range of animals ex...
Buhl R, Meldgaard C, Barbesgaard L.Electrocardiographic reference values of clinically normal horses during exercise are a prerequisite when evaluating horses with poor performance or horses presented with cardiac abnormalities (e.g. valvular regurgitation). No published studies have reported cardiac rhythms of clinically normal showjumping horses. Objective: To demonstrate the feasibility of obtaining exercise electrocardiogram (ECG) in normal horses during showjumping and also to document the prevalence and frequency of arrhythmias in association with exercise. Methods: Thirty-four healthy showjumping horses aged 4-13 years (...
Marr CM, Reef VB, Brazil TJ, Thomas WP, Knottenbelt DC, Kelly DF, Baker JR, Reimer JM, Maxson AD, Crowhurst JS.This report describes the history, clinical, electrocardiographic and echocardiographic findings, treatment, outcome and post-mortem findings in seven horses with aorto-cardiac fistula. Affected horses included 5 stallions, one gelding and one mare; 2 each of the Thoroughbred, Arabian and Standardbred breeds and one Thoroughbred-cross with a mean +/- s.d. age of 12 +/- 4 years, range 6-18 years. The presenting signs were acute distress (four horses), exercise intolerance (two horses) and the lesion was detected during a routine examination in one horse. Five horses had monomorphic ventricular ...
Linton RA, Young LE, Marlin DJ, Blissitt KJ, Brearley JC, Jonas MM, O'Brien TK, Linton NW, Band DM, Hollingworth C, Jones RS.To assess the suitability of lithium dilution as a method for measuring cardiac output in anesthetized horses, compared with thermodilution and transesophageal Doppler echocardiography. Methods: 6 horses (3 Thoroughbreds, 3 crossbreeds). Methods: Cardiac output was measured in 6 anesthetized horses as lithium dilution cardiac output (LiDCO), thermodilution cardiac output (TDCO), and transesophageal Doppler echocardiographic cardiac output (DopplerCO). For the LiDCO measurements, lithium chloride was administered i.v., and cardiac output was derived from the arterial lithium dilution curve. Sod...
Al-Haidar A, Farnir F, Deleuze S, Sandersen CF, Leroux AA, Borde L, Cerri S, Amory H.Little is known about the effect of various animal's signalment variables on echocardiographic reference values in the equine species. This study was performed to evaluate the effect of sex, breed, age and body weight (BW) on echocardiographic measurements in the equine species. Echocardiography was performed on 212 ponies or horses of various breeds, aged from 1 day to 37 years old (mean±SD: 7.8 ± 5.8 years), BW 38-890 kg (mean ± SD: 421 ± 133 kg), and free of cardiac disease. Fifty of those animals aged from 2 months to 35 years old (mean ± SD: 11.6 ± 6.4 years old); BW 77-662 kg (mean...
Fraipont A, Van Erck E, Ramery E, Richard E, Denoix JM, Lekeux P, Art T.Thirty-eight endurance horses underwent clinical and ancillary examinations, including haematological and biochemical evaluation, standardised exercise tests both on a treadmill and in the field, Doppler echocardiography, impulse oscillometry, video endoscopy and collection of respiratory fluids. All of the examined poorly performing horses were affected by subclinical diseases, and most of them had multiple concomitant disorders. On the contrary, the well-performing horses were free of any subclinical disease. The most frequently diagnosed diseases were respiratory disorders, followed by musc...
McConachie E, Barton MH, Rapoport G, Giguère S.Cardiac output (CO) is not routinely measured in critically ill adult horses because of invasiveness of currently validated methods. Noninvasive CO monitoring would complement clinical assessment of hemodynamic status in adult horses. Objective: Volumetric methods for measuring CO will have better agreement with lithium dilution than Doppler-based methods. Methods: Eight healthy adult horses. Methods: Prospective study. CO was manipulated with continuous rate infusions of dobutamine and romifidine to achieve high and low CO states, respectively. At each level, CO was measured by lithium diluti...
Buhl R, Ersbøll AK, Larsen NH, Eriksen L, Koch J.To evaluate by echo- and electrocardiography the cardiac effects of sedation with detomidine hydrochloride, romifidine hydrochloride or acepromazine maleate in horses. Methods: An experimental study using a cross-over design without randomization. Methods: Eight clinically normal Standardbred trotters. Methods: Echocardiographic examinations (two-dimensional, guided M-mode and colour Doppler) were recorded on five different days. Heart rate (HR) and standard limb lead electrocardiograms were also obtained. Subsequently, horses were sedated with detomidine (0.01 mg kg(-1)), romifidine (0.04 mg ...
Zucca E, Ferrucci F, Croci C, Di Fabio V, Zaninelli M, Ferro E.The aim of this study was to obtain echocardiographic measurements and establish reference ranges for 14 parameters in Standardbred racehorses in training. Background: Several studies have been published about cardiac measurements in Thoroughbreds, Standardbreds, National Hunt horses, Warmbloods and ponies; however, not all parameters have been published for the Standardbred trotter in training. Methods: Thirty normal Standardbred racehorses in training were assessed by two-dimensional echocardiography (2-D) and M-mode echocardiography using standardized imaging planes. Mean values, standard d...
Patteson MW, Gibbs C, Wotton PR, Cripps PJ.Cardiac dimensions and indices of cardiac function were measured in 29 clinically normal adult Thoroughbreds (TB) which performed minimal exercise using guided M-mode and two-dimensional (2-D) echocardiography, from a variety of image planes and measurement methods, and standardised imaging planes based on intracardiac anatomical landmarks. The different methods of measuring these variables were compared. The variables which were considered to be most valuable for quantitative echocardiography were measured in a further 9 horses. Comparable measurements of cardiac dimensions can be obtained fr...
HOLT JP, RHODE EA, PEOPLES SA, KINES H.Studies of left ventricular volume and pressure have been carried out in the control state in four classes of intact anesthetized mammals (horses, cattle, swine, and dogs), body weights of which varied 54-fold. On the basis of these studies of both large and small hearts, extending over a wide range, a pattern of function for the left ventricle of all mammals has been described. Mathematical equations are given describing the interrelationships between left ventricular end-diastolic volume and end-systolic volume, stroke volume, cardiac output, stroke-work, heart rate, and total peripheral res...
Trachsel DS, Schwarzwald CC, Bitschnau C, Grenacher B, Weishaupt MA.Atrial natriuretic peptide (ANP) and cardiac troponin I (cTnI) serve as biomarkers for increased cardiac pressure/volume loading and for myocardial stress or damage. The objective was to describe the time course of plasma ANP concentrations (CpANP) and plasma cTnI concentrations (CpcTnI) in horses with mitral regurgitation (MR) compared to healthy horses at rest and after exercise, and to describe the relationship of CpANP with cardiac dimensions and intracardiac pressures. Methods: 15 healthy Warmblood horses and 7 Warmblood horses with MR. Methods: Cardiac dimensions at rest were measured us...
Sleeper MM, Kearns CF, McKeever KH.Chronic administration of pharmacological levels of beta2-agonists have been shown to have toxic effects on the heart; however, no data exist on cardiac function after chronic clenbuterol administration. The purpose of this study was to examine the effect of therapeutic levels of clenbuterol on cardiac performance. Methods: Twenty unfit Standardbred mares were divided into four experimental groups: clenbuterol (2.4 microg.kg(-1) twice daily 5 d.wk(-1)) plus exercise (20 min at 50% .VO(2max)) (CLENEX; N = 6), clenbuterol (CLEN; N = 6), exercise (EX; N = 4), and control (CON; N = 4). M-mode and ...
Barbesgaard L, Buhl R, Meldgaard C.Exercise-associated arrhythmias are important differentials when evaluating poor performance sport horses. However, most studies of arrhythmias have been conducted in racehorses and therefore there is a paucity of knowledge concerning the prevalence and significance of exercise-associated arrhythmias in riding horses. Objective: The objective of this study was to examine the prevalence of arrhythmias, particularly supraventricular premature complex (SVPCs) and ventricular premature complex (VPCs), associated with exercise in normal performing dressage horses. Methods: In total, 21 normal perfo...
Schwarzwald CC, Schober KE, Berli AS, Bonagura JD.Noninvasive assessment of left-ventricular (LV) function is clinically relevant, but is incompletely studied in horses. Objective: To document the feasibility, describe the techniques, and determine the reliability of 2D speckle tracking (2DST) for characterization of LV radial and circumferential wall motion in horses. Methods: Three Standardbreds, 3 Thoroughbreds; age 8-14 years; body weight 517-606 kg. Methods: Observational study. Repeated 2-dimensional echocardiographic examinations were performed in unsedated horses by 2 observers and subsequently analyzed by 2DST. Test reliability was d...
van Loon G, Fonteyne W, Rottiers H, Tavernier R, Jordaens L, D'Hont L, Colpaert R, De Clercq T, Deprez P.The purpose of the present study was to develop a feasible and safe technique for dual-chamber pacemaker implantation in healthy horses. Implantation was performed in a standing, tranquilized horse and in ponies. Atrial and ventricular leads were transvenously inserted through the cephalic vein, and a subcutaneous pacemaker pocket was created between the lateral pectoral groove and the manubrium sterni in 6 equids. Positioning of each lead was guided by echocardiography and by measuring the electrical characteristics of the lead. The implantation procedure lasted about 4 hours in each animal a...
Flethøj M, Schwarzwald CC, Haugaard MM, Carstensen H, Kanters JK, Olsen LH, Buhl R.Prolonged exercise in human athletes is associated with transient impairment of left ventricular (LV) function, known as cardiac fatigue. Cardiac effects of prolonged exercise in horses remain unknown. Objective: To investigate the effects of prolonged exercise on LV systolic and diastolic function in horses. Methods: Twenty-six horses competing in 120-160 km endurance rides. Methods: Cross-sectional field study. Echocardiography was performed before and after rides, and the following morning, and included two-dimensional echocardiography, anatomical M-mode, pulsed-wave tissue Doppler imaging...
Nath LC, Anderson GA, Hinchcliff KW, Savage CJ.To measure the cardiac troponin I (cTnI) concentration in horses and determine whether it could be used in the diagnosis of myocardial disease, as well as determining the association between cTnI and survival. Methods: Prospective, observational study. Methods: Physical examination, echocardiography, telemetric electrocardiography and postmortem were used to diagnose cardiac disease. Diagnoses were grouped as myocardial disease, structural heart disease or lone arrhythmia. Blood samples were collected at admission for cTnI analysis and the results were compared with those for 18 healthy horses...
Phillips W, Giguère S, Franklin RP, Hernandez J, Adin D, Peloso JG.Cardiac troponin I (cTnI), a myocardial polypeptide, is a highly sensitive and specific biomarker of myocardial injury in people and dogs. The structure of cTnI is highly conserved across species, and equine myocardium has high reactivity with human immunoassays. The purpose of this study was to describe cTnI concentrations in normal pastured and race-training Thoroughbred horses. Ten horses on pasture and 10 horses in race training were studied. Horses were considered normal on the basis of physical examination, training performance, electrocardiography (ECG), and echocardiography. Serum cTnI...
