The aorta is the main artery in horses, responsible for transporting oxygenated blood from the left ventricle of the heart to the rest of the body. It is a large, elastic blood vessel that withstands high pressure and plays a vital role in the circulatory system. The structure and function of the equine aorta can be affected by various conditions, including aneurysms, rupture, and degenerative changes, which may impact a horse's health and performance. This page compiles peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, pathologies, and clinical implications of aortic health in horses.
Raisis AL, Young LE, Blissitt KJ, Brearley JC, Meire HB, Taylor PM, Lekeux P.The purpose of this study was to compare the haemodynamic effects of equipotent isoflurane and halothane anaesthesia. Six adult horses were investigated on two separate occasions at least 4 weeks apart. On both occasions anaesthesia was induced by ketamine 2.2 mg/kg bwt given 5 min after i.v. administration 100 microg/kg bwt romifidine. Anaesthesia was maintained either by halothane or isoflurane (end-tidal concentrations 0.9-1.0% and 1.3-1.4%, respectively). Horses were ventilated by intermittent positive pressure to maintain PaCO2 between 40-50 mmHg. Haemodynamic variables were measured usin...
Cornelisse CJ, Schott HC, Olivier NB, Mullaney TP, Koller A, Wilson DV, Derksen FJ.An 18-year-old Thoroughbred gelding was evaluated because of sudden onset of ventricular tachycardia and signs of colic. Three years earlier, a diastolic decrescendo murmur, consistent with aortic regurgitation, had been detected, but the horse continued to perform well and compete successfully. Cardiac ultrasonographic examination revealed a defect in the interventricular septum below the aortic root, and serum concentrations of cardiac troponin I (cTnI) were higher than those measured in clinically normal horses. Repeated development of tachyarrhythmia during hospitalization prompted a decis...
Young LE, Wood JL.Cardiac auscultation was carried out on 111 Thoroughbred horses age 2-5 years to test the hypothesis that athletic training might influence the development of atrioventricular (AV) valve regurgitation in young Thoroughbreds. Murmurs of valvular regurgitation were identified and graded on a 1-6 scale. There were 2 sources of auscultation data: 1) 55 2-year-old horses that were examined by auscultation before training commenced and 9 months later when at race fitness; 2) 56 horses age 2-5 years that were examined on one occasion only (25 2-year-olds, 23 3-year-olds, five 4-year-olds and five 5-y...
Renaudin CD, Gillis CL, Tarantal AF, Coleman DA.Transrectal and transabdominal ultrasonography were performed on normal pregnant mares (n=10) at 2 week intervals from day 100 of gestation to parturition to evaluate fetal growth. Several fetal anatomical regions (head, eye, aorta, abdomen, rib, gonad, kidney and femur) were imaged and measured using standardized scan plans. The results of these analyses indicate that all of the biometric parameters correlate strongly with the day of gestation. Growth charts were developed, which demonstrate that the following variables have linear relationships with the day of gestation on which they were me...
Shirai W, Momotani E, Sato T, Kashima T, Saito T, Itoi Y.A case of dissecting aortic aneurysm in a 4-year-old male thoroughbred horse is reported. The horse had a history of inflammation in the right thigh and a fever 2 weeks before sudden death. At necropsy, aortic aneurysms were observed from the aortic valve to the aortic arch, spreading over a distance of 40 cm. An irregular rupture of the intima of the ascending aorta was located in the cardiac side of a ramification to the tunica branchiocephalicus communis. An intramural haematoma, apparent on the cut surface and in the pericardium, had caused cardiac tamponade and sudden death.
Butt TD, MacDonald DG, Crawford WH, Dechant JE.A 14-month-old filly with chronic pharyngitis was diagnosed with incomplete esophageal constriction and megaesophagus due to a persistent right aortic arch. This report is unusual because clinical signs of respiratory dysfunction secondary to chronic regurgitation occurred prior to the recognition of dysphagia.
Young LE, Blissitt KJ, Clutton RE, Molony V.To describe the haemodynamic effects of a 60 min infusion of dopamine 4 microg/kg bwt/min during halothane anaesthesia, 7 mature Thoroughbred horses were studied. The infusion began 1 h after induction of anaesthesia by romifidine (100 microg/kg) and ketamine (2.2 mg/kg bwt). Throughout the period of dopamine infusion and for 30 min after its discontinuation, the horses were ventilated by intermittent positive pressure to maintain PaCO2 between 4.6-5.4 KPa. Inspired halothane concentration was adjusted to maintain an end tidal halothane concentration of 0.9%. Haemodynamic variables were measur...
Manohar M, Goetz TE.To examine regional distribution of blood flow in the brain of horses at rest and during exercise. Methods: 9 clinically normal horses. Methods: Regional brain blood flow was measured using radionuclide-labeled 15-microns-diameter microspheres injected into the left ventricle, while reference blood samples were obtained from the aorta. Results: At rest, cerebral cortex and caudate nuclei received significantly higher blood flow, compared with cerebral white matter. A similar perfusion heterogeneity existed in the cerebellum. In the brain stem, a gradual tapering of blood flow from thalamus-hyp...
Moore LA, Johnson PJ, Bailey KL.A six-day-old Missouri foxtrotter colt was examined because it had had diarrhoea since it was 24 hours old. A diagnosis of colitis, septicaemia, and disruption of the arterial blood flow to the pelvic limbs was made on the basis of clinical and laboratory findings. Despite intensive medical therapy, the foal died 13 hours after being examined. Postmortem examination revealed diffuse fibrinous enteritis with lymphoid necrosis, multifocal fibrinonecrotic typhlocolitis, disseminated intravascular coagulation, and a large occluding thrombus at the aortic termination. The results of bacteriological...
Curran S, Urven L, Ginther OJ.Eighteen equine embryos, 3 each on Days 20, 22, 24, 26, 28 and 30 post ovulation, were collected transcervically by uterine lavage, fixed in 4% paraformaldehyde and embedded in paraffin wax. Ten micron serial sections were stained to determine alkaline phosphatase (AP) activity in the cells. Positive cells were counted and their approximate location determined. The cells were approximately 8 microm in diameter and the entire cell, except the nucleus, stained strongly with many small round areas of intense staining in the cytoplasm. The cells varied from round to elongated in shape and pseudopo...
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 ...
Yokoyama S, Matsuo K, Fujiwara T, Jibiki T, Okajima Y, Aotsuka H.We reported a successful case of the modified Norwood operation for a 21-day-old neonate with hypoplastic left heart syndrome (MS and AS) associated with an aberrant right subclavian artery and a persistent left superior vena cava. The modified Norwood operation was performed without total circulatory arrest and Cardiac arrest. A 4 mm Gore-Tex graft, which was anastomosed between the right carotid artery and the right pulmonary artery for systemic-pulmonary shunt, was used for cerebral perfusion during aortic arch reconstruction. Coronary perfusion was performed with a small cannula placed on ...
Ross MW, Maxson AD, Stacy VS, Buchanan KB.First-pass radionuclide angiography of the terminal aorta was performed in 3 normal horses and a 6-year-old Standardbred intact male with aortoiliac thromboembolism. Thromboembolism caused chronic bilateral hind limb lameness, more severe in the right hind limb, was detected by rectal examination, and confirmed using transrectal ultrasonography. Using 99mTc-HDP, first-pass radionuclide angiography was combined with hind limb and pelvis bone (delayed) scintigraphy and revealed marked reduction in blood flow through both external iliac arteries and absence of blood flow in the internal iliac art...
Young LE, Blissitt KJ, Clutton RE, Molony V.To evaluate the hemodynamic effects of a 60-minute infusion of dopexamine in horses anesthetized with halothane. Methods: 7 adult Thoroughbreds. Methods: Measurements of left ventricular function obtained by transesophageal Doppler echocardiography and cardiac catheterization. Results: Infusion of dopexamine (4 micrograms/kg of body weight/min) significantly increased heart rate, cardiac output, maximal rates of increase and decrease of left ventricular pressure, and maximal acceleration and maximal velocity of aortic blood flow. Left ventricular ejection time significantly increased, and pre-...
Blissitt KJ, Young LE, Jones RS, Darke PG, Utting J.Measurement of cardiac output by Doppler echocardiography were compared to simultaneous measurements by thermodilution in 9 conscious horses. In the Doppler technique, mean blood flow velocities for estimation of cardiac output were recorded from the aorta and pulmonary artery. The flow area of each vessel was calculated from the vessel diameter, measured from a 2-dimensional ultrasound image. Differences in the site and method of measuring the vessel diameter altered the estimation of cardiac output by the Doppler method. Cardiac output was modified by the i.v. infusion of 4 micrograms/kg bwt...
Reppas GP, Canfield PJ, Hartley WJ, Hutchins DR, Hoffmann KL.An echocardiographical and clinical pathological investigation of the rapid loss of weight by a yearling thoroughbred filly revealed an atrial septal defect, a ventricular septal defect and hyperfibrinogenaemia. A post mortem examination confirmed the cardiac abnormalities and revealed a severe thoracic aortitis. It is proposed that the idiopathic thoracic aortitis contributed to the horse's compromised cardiovascular homoeostasis.
Brama PA, Rijkenhuizen AB, van Swieten HA, Warmerdam EP.The prognosis of aortic-iliac thrombosis (TAI) is usually considered to be poor, although affected horses are reported to have recovered following treatment with sodium gluconate. This paper presents some diagnostic techniques to monitor the development of hypoxemia in the diseased limb and to visualise the extension of the thrombosis into the femoral artery. Also, a surgical technique using a Fogarty thrombectomy catheter for partial or total removal of thrombi to restore blood flow, is described. One horse recovered completely, allowing it to resume its former career, the other horse improve...
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...
Blissitt KJ, Bonagura JD.Colour flow Doppler echocardiography is a technique that is used with two-dimensional (2-D) echocardiography to study blood flow patterns in the heart and blood vessels. This method was used to define normal flow patterns and to evaluate valvular function in 40 clinically normal Thoroughbred and Thoroughbred cross horses. Flow patterns from 10 standardised echocardiographic images were described in relation to anatomic landmarks and timing during the cardiac cycle. Consistent intracardiac flow patterns were identified in the normal horses. High velocity flow signals or regurgitant jets were re...
Blissitt KJ, Bonagura JD.Reference values were established for selected Doppler derived variables from a group of 40 normal Thoroughbred and Thoroughbred cross horses. Standard two-dimensional (2-D) images used for guiding the Doppler sampling site allowed accurate alignment with flow. Tricuspid inflow velocities during rapid filling (E) and atrial contraction (A) were significantly higher when recorded from a right parasternal angled view than from a right parasternal long-axis view. In 8 horses the tricuspid inflow peak A velocity was higher than the peak E velocity. The peak acceleration of blood flow was higher (P...
Manohar M, Goetz TE, Hutchens E, Coney E.Right atrial, pulmonary artery, pulmonary capillary, pulmonary artery wedge, and systemic blood pressures of strenuously exercising horses increase markedly. As a consequence, myocardial metabolic O2 demand in exercising horses must be high. Experiments were, therefore, carried out on 9 healthy, exercise-conditioned horses (2.5 to 8 years old; 481 +/- 16 kg) to ascertain the regional distribution of myocardial blood supply in the atria and ventricles at rest and during exercise. Blood flow was measured, using 15-micron-diameter radionuclide-labeled microspheres that were injected into the left...
Kim DY, Hodgin EC, Lopez MK, Nasarre C.A large primary retroperitoneal sublumbar neoplasm in a horse, with disseminated neoplastic foci in the brain, lung, kidney and spleen is described. The diagnosis was based on light microscopical studies and positive immunostaining for neuron-specific enolase. Because of the location of the primary tumour mass, the aortico-sympathetic ganglion (organ of Zukerkandl) is proposed as the origin.
Stadler P, Weinberger T, Deegen E.Twenty adult warm blooded horses (body weight 585 +/- 59 kg) were evaluated with pulsed doppler echocardiography. Locations for the transducer and the sample volume were determined to get typical blood flow tracings of the equine heart. Angle of doppler beam was between 37 degrees and 40 degrees in right heart atrioventricular flow tract and between 44 degrees and 47 degrees in left heart atrioventricular flow tract. Peak blood flow velocity (angle corrected) was 0.71 +/- 0.17 m/s in tricuspid valve and 0.92 +/- 0.22 in mitral valve. In right and left atrioventricular flow tracts in all sample...
Bergentz SE.Jean Martin Charcot was the first to give a detailed description of intermittent claudication, and a correct interpretation of the mechanism behind the symptoms. He borrowed the name of the syndrome from the veterinarian literature, where it had been described to occur in horses, and caused by inflammatory changes in aorta at the origin of the large vessels to the extremities. The case presented by Charcot was a man with a traumatic pseudoaneurysm in his common iliac artery. He had in addition an arterio-enteric fistula, a condition which probably had not been described before.
Sikkes BP, Manohar M, Duren SE, Day J, Baker JP.Experiments were carried out on 8 healthy ponies to examine the effects of prolonged submaximal exercise on regional distribution of brain blood flow. Brain blood flow was ascertained by use of 15-microns-diameter radionuclide-labeled microspheres injected into the left ventricle. The reference blood was withdrawn from the thoracic aorta at a constant rate of 21.0 ml/min. Hemodynamic data were obtained with the ponies at rest (control), and at 5, 15, and 26 minutes of exercise performed at a speed setting of 13 mph on a treadmill with a fixed incline of 7%. Exercise lasted for 30 minutes and w...
Parmar J, Winterbottom A, Cooke F, Lever AM, Gaunt M.Streptococcus equi is a common equine infectious disease, but transmission to man is rare and confined to those who commonly come into close contact with horses. Similarly, prosthetic stent graft infection is a rare complication of endovascular aortic aneurysm repair. We describe the first reported case of aortic stent graft with S. equi occurring in a professional racehorse trainer. Clinical presentation, investigations, imaging and management of this case are described. In conclusion, clinicians should consider infection with rare organisms in patients with prosthetic implants who regularly ...
Moore JN, Kintner LD.Squamous cell carcinoma involving the pars esophagea of the stomach caused recurrent esophageal obstruction in an 11 year old Pinto gelding. The tumor encircled the esophagus and was attached to the diaphragm, spleen, aorta, left adrenal gland and kidney. Definitive diagnosis was provided by biopsy of the mass via standing left flank laparotomy.
Butt TD, MacDonald DG, Crawford WH, Dechant JE.A 14-month-old filly with chronic pharyngitis was diagnosed with incomplete esophageal constriction and megaesophagus due to a persistent right aortic arch. This report is unusual because clinical signs of respiratory dysfunction secondary to chronic regurgitation occurred prior to the recognition of dysphagia.
Akbari G, Asadiahranjani B, Goodarzi N, Shokrollahi S.Donkeys are a member of the horse family (Equidae) and share a common ancestor. However, in morphological terms, donkeys and horses are regarded as two separate subgenus. Given variations in the branching pattern of the brachiocephalic trunk (BCT) in different species of animals and the use of donkeys in anatomy courses at colleges of veterinary medicine, we conducted this study in order to investigate the branching patterns of BCT and to describe detailed morphological information regarding donkeys. Seventeen mature donkeys were examined following euthanasia by exsanguination from the common ...
Cranley JJ, McCullagh KG.The hearts and aortas of 2076 unselected horses of all ages were examined immediately after slaughter. Focal zones of fibrosis, observed in the myocardium of 14.3 per cent of hearts examined, were found in both atria and ventricles and were unrelated to age. Microscopically the majority of lesions involved myocardial fibre lysis and replacement fibrosis, although acute infarction was present in some cases. Intramyocardial arterioles in or adjacent to the lesions exhibited occlusive arteriosclerotic changes whereas those elsewhere remained patent. The evidence strongly suggests that the myocard...
Manohar M, Hassan AS.To ascertain whether costal diaphragm engages in ammonia and lactate production (like limb muscles) during high-intensity short-term exercise, experiments were carried out on six healthy trained ponies in which phrenic venous catheters had been implanted 5-9 days earlier. Simultaneous anaerobically obtained blood samples from abdominal aorta and the phrenic vein at rest and during 4 min of exertion at 32 km/h and at a 7% grade were analyzed for blood-gas variables as well as lactate and ammonia concentrations using standard procedures. At rest, heart rate was 47 +/- 4 beats/min and the diaphra...
Blissitt KJ, Bonagura JD.Colour flow Doppler echocardiography is a technique that is used with two-dimensional (2-D) echocardiography to study blood flow patterns in the heart and blood vessels. This method was used to define normal flow patterns and to evaluate valvular function in 40 clinically normal Thoroughbred and Thoroughbred cross horses. Flow patterns from 10 standardised echocardiographic images were described in relation to anatomic landmarks and timing during the cardiac cycle. Consistent intracardiac flow patterns were identified in the normal horses. High velocity flow signals or regurgitant jets were re...
Holmes JR, Alps BJ.The paper describes observations on the distributions of the P, QRS and T cardiac vectors in the horizontal plane, comparing healthy horses with those with arrhythmia and cardiac murmurs. Deviation of the T vector from the normal range appeared to occur most commonly in association with cardiac murmurs, particularly those involving the semilunar valves and aorta.
Decloedt A, Ven S, De Clercq D, Rademakers F, van Loon G.Aortic regurgitation (AR) may lead to left ventricular (LV) dilatation, cardiac arrhythmias and heart failure. Close follow-up of horses with AR is therefore paramount to detect onset of cardiac decompensation. The aim of this study was to examine whether two-dimensional speckle tracking (2DST) can be used to detect altered myocardial function in horses with chronic AR compared to control horses. Speckle tracking was performed on short axis and long axis images of the LV in 29 healthy Warmblood horses and 57 Warmblood horses with AR. Radial, circumferential and longitudinal strain, strain rate...
Parks C, Manohar M, Lundeen G.To examine the effects of tachycardia on coronary circulation, transmural distribution of myocardial blood flow (MBF, 15-micron diameter radionuclide-labeled microspheres) was studied in six healthy adult ponies at rest (heart rate = 60 +/- 7 beats . min-1), during ventricular pacing at 150 and 200 beats . min-1, as well as with ventricular pacing at 250 beats . min-1 before and during maximal coronary vasodilatation (iv adenosine infusion; 4 mumole . kg-1 . min-1). Mean aortic pressure and cardiac output were unchanged from control values with ventricular pacing. Whereas ventricular pacing at...
Freccero F, Cordella A, Dondi F, Castagnetti C, Niinistö K, Cipone M.In dogs, due to better alignment with the aortic outflow, the subcostal (SC) transducer site provides greater Doppler-derived velocities than those obtained from the left parasternal view. The feasibility of this imaging approach has never been described in equine echocardiography. Objective: The objective of this study was to evaluate the feasibility of the SC view in newborn foals and compare aortic two-dimensional and Doppler-derived velocity measurements with those of standard parasternal long-axis (LAX) views. Methods: A prospective observational study. Methods: Twenty-three newborn healt...
Decloedt A.Pericardial, myocardial, and great vessel diseases are relatively rare in horses. The clinical signs are often nonspecific and vague, or related to the underlying cause. Physical examination usually reveals tachycardia, fever, venous distension or jugular pulsation, a weak or bounding arterial pulse, ventral edema, and abnormal cardiac auscultation such as arrhythmia, murmur, or muffled heart sounds. The prognosis depends on the underlying cause and the disease progression, and ranges from full recovery to poor prognosis for survival. This article focuses on the etiology, diagnosis, prognosis,...
Rijkenhuizen AB, Sinclair D, Jahn W.Aortoiliac thrombosis (AIT) is a progressive vascular disease characterised by an exercise-induced hindlimb lameness. After developing a surgical technique, a follow-up study was required. Objective: To assess the surgical results of a surgical thrombectomy in horses with AIT, a chronic arterial occlusive disease of the aorta and its caudal arteries. Methods: Seventeen cases showed the typical signs of AIT and diagnosis was confirmed by Doppler-ultrasonography. Average age of the horses was 12 years. Seven stallions, 6 mares and 4 geldings were included. Results: The thrombus was located in th...
Roby KA, Reef VB, Shaw DP, Sweeney CR.A 15-year-old, Standardbred broodmare with an aortic sinus aneurysm developed rupture of the aneurysm with subsequent rupture of a tricuspid valve chorda tendinae, tricuspid regurgitation, acute right-sided congestive heart failure, and pulmonary thromboembolism. Shunting of blood from the aorta through the ruptured aneurysm into the right ventricle resulted in decreased renal perfusion and acute renal failure. Initially, treatment of the mare with analgesics, fluids, and digoxin resulted in clinical improvement, but the mare's condition deteriorated after 8 days and the mare was euthanatized ...
Boegli J, Schwarzwald CC, Mitchell KJ.Noninvasive blood pressures (NIBP) and pulse pressures (PP) have not been published in horses with aortic and mitral regurgitation (AR or MR). Objective: To investigate NIBP and PP in healthy Warmblood horses and horses with AR and MR and propose PP cutoffs to identify and stage AR severity. Methods: Seventy-three Warmblood horses (healthy, 10; AR, 31; MR, 32). Methods: Retrospective study. All horses had NIBP and an echocardiogram recorded. Cases were categorized based on severity of regurgitation. Pulse pressures were compared among healthy, MR, and AR groups and among AR severity groups. Cu...
Manohar M.Tracheobronchial circulation during exercise has previously not been examined. Therefore blood flow to the trachea and bronchi (up to 7th generation of branching) was studied in seven healthy adult ponies at rest and during the 3rd and 10th min of exercise performed at a treadmill speed setting of 25 km/h. The ambient air temperature varied from 19 to 20 degrees C and humidity from 35 to 45%. To determine blood flow radionuclide-labeled 15-microns-diameter microspheres were injected into the left ventricle via a catheter advanced from the left carotid artery (exposed using local anesthesia), a...
Grosenbaugh DA, Amoss MS, Hood DM, Morgan SJ, Williams JD.Epidermal growth factor (EGF) receptor binding kinetics and EGF-mediated stimulation of DNA synthesis and cellular proliferation were studied in cultured vascular smooth muscle cells (VSMC) from the equine thoracic aorta. Binding studies, using murine 125I-labeled EGF, indicate the presence of a single class of high-affinity binding sites (apparent KD = 2.8 X 10(-11) M), with an estimated maximal binding capacity of 5,800 sites/cell. EGF stimulated [3H]thymidine uptake in confluent quiescent monolayers in a dose-dependent fashion, half-maximal stimulation occurring at 7.5 X 10(-11) M. Likewise...
Thomas WP, Madigan JE, Backus KQ, Powell WE.Cardiopulmonary function was studied in 10 full-term healthy foals from birth to 14 days of age. Systemic and pulmonary haemodynamics were recorded in lateral recumbency via indwelling aortic and pulmonary artery catheters. Mean body weight increased from 45.4 +/- 2.4 kg on Day 1 to 70.6 +/- 6.1 kg on Day 14. All foals had a continuous murmur of patent ductus arteriosus for 3-6 days. From Day 1 (12 h old) to Day 14, heart rate increased (89 +/- 4 to 95 +/- 5/min), mean aortic pressure increased (87.7 +/- 1.9 to 100.3 +/- 3.2 mmHg), mean pulmonary artery pressure decreased (38.6 +/- 4.6 to 27.4...
Bonagura JD, Pipers FS.A horse, a cow, and a dog with aortic valve vegetative endocarditis were studied by M-mode echocardiography. Echocardiographic abnormalities of the aortic valve, mitral valve, and left ventricle were observed. These features were identical to those reported in human beings with aortic valve endocarditis. Abnormalities associated with aortic valve endocarditis included irregular thickening of the valve, multiple linear echoes in the aortic root, diastolic prolapse of the aortic vegetation, and diastolic fluttering of a torn aortic valve. Some of these features were found in each animal. The con...
Brown CM, Holmes JR.Using microtransducers, the intracardiac phonocardiogram was recorded in 8 horses from the right heart and in 6 of them also on the left side. All 4 heart sounds were recorded but not in all sites. Their timing was related to pressure events. Systolic ejection murmurs were recorded in both the pulmonary artery and the aorta. Diastolic murmurs were recorded in 2 horses with aortic regurgitation, with maximum amplitude in the left ventricle. The findings were similar to those reported in man and agree with some of the recent concepts on heart sound production.
Versnaeyen H, Saey V, Vermeiren D, Chiers K, Ducatelle R.A 7-year-old warmblood mare showed sudden onset of mild intermittent haemoptysis. Clinical examination revealed no significant abnormalities. Haematological examination showed mild anaemia, hypoalbuminaemia and neutrophilia. Coagulation tests were normal. Endoscopic examination revealed unilateral pulmonary haemorrhage with blood clots in the bronchi and trachea. Treatment with antibiotics was started and the horse was given stable rest. Two weeks later, the horse was found dead with blood and frothy sputum leaking from the nostrils. Post-mortem examination revealed a large thoracic aortic ane...
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...
Pereira VP, Seyfert CE, Santos JML, de Morais-Pinto L.The position of the coronary ostia was investigated in 70 segments of the aorta from young adult crossbred horses. After fixation with a 4% buffered aqueous formaldehyde solution and cautious dissection of the aortic bulb, the morphometric relationships between the coronary ostium and the aortic valvar elements were digitally analysed with the support of Image-Pro Plus® software. In horses, the left coronary ostium was near to the right valvular commissure in all cases (100%) analysed in this study. The left coronary ostium was at the level of the intercommissural line in 57.1% and below it i...
Vitale V, Laurberg M, van Galen G.Aortic valve malformation is a common congenital abnormality reported in human medicine. The malformation is characterised by an increased or decreased number of cusps. Anatomical variations of the aortic valve that have been documented in humans include unicuspid, bicuspid, quadricuspid and quinticuspid valves. Two reports described a quadricuspid aortic valve in horses associated with either a ventricular septal defect (VSD) or tetralogy of Fallot. In this case report we describe the clinical and echocardiographic findings of a horse with a quadricuspid aortic valve as single congenital abno...
Pipers FS, Hamlin RL.Echocardiograms were obtained from 25 standing, clinically normal horses, using an ultrasonic recording device. The echobeam penetrated the right thoracic wall in the area of the 4th to 5th intercostal space, with a frequency of 2.5 mHz. Measurements of left ventricular wall thickness generated a mean value of 3.2 +/- 0.18 (SEM)cm, whereas the left ventricular chamber diameter in diastole was 9.3 +/- 0.30 cm and in systole was 5.7 +/- 0.23 cm. The aortic root dimensions had a mean of 7.7 cm, with a SEM of 0.16. Mitral valve closing slope (E-F) was calculated to be 17.7 +/- 0.87 mm/second, and ...
Sarin EL, Moore JB, Moore EE, Sheppard FR.The majority of blunt aortic injuries (BAIs) are related to "rapid deceleration"mechanisms with motor vehicle crashes (MVCs) and falls accounting for the majority of these injuries. However, in recent years improved understanding of the mechanisms behind blunt aortic injury has led
to an expansion of the "usual suspects" when evaluating blunt thoracic injury. Compression of the thoracic cage has proven to have a significant potential for blunt aortic injury, even in
instances without "high-speed" mechanisms commonly sought when explaining the history for BAI risk factors. In this we report, ...
