The equine cardiovascular system, particularly the heart, is fundamental to maintaining the health and performance of horses. The heart is responsible for pumping oxygenated blood throughout the body, supporting vital functions and physical activity. In horses, the heart's structure and function are adapted to meet the demands of both rest and exertion, with notable features such as a large cardiac output and efficient blood circulation. Conditions affecting the equine heart, such as arrhythmias, valvular diseases, and myocardial disorders, can significantly impact a horse's well-being and athletic capability. This page aggregates peer-reviewed research studies and scholarly articles that explore the anatomy, physiology, and pathophysiology of the equine heart, as well as diagnostic and therapeutic approaches to managing cardiac health in horses.
WEGELIUS O.The number of mast cells per area and volume have been counted in the pleura, pericardium and capsula hepatis of cattle and horse.
The capsula hepatis of cattle contains a 5—10 times larger number of mast cells than the other tissues. The pleura pulmonalis showed a content of mast cells which was only a fraction of that in the liver capsule. The high histamine content found by Riley and coworkers when analyzing ox pleura seem to indicate that histamine is liberated not only from the mast cells, but also from other elements of the tissues.
Alexeenko V, Tavanaeimanesh H, Stein F, Gold J, Hughes L, McCue M, Marr C, Durward-Akhurst S, Jeevaratnam K.Cardiac arrhythmias are common in healthy athletic horses and may lead to poor athletic performance or exercise-associated sudden death. Early detection of high-risk horses is an important goal of cardiovascular diagnostics. We hypothesised that non-linear analysis of electrocardiogram disorderliness can be used to identify horses exhibiting intermittent ectopic atrial and ventricular heart rhythm abnormalities at exercise using brief, artifact-free recordings of normal sinus rhythm electrocardiograms collected at submaximal heart rates. In a convenience prospective cross-sectional study, ambu...
Buschmann E, Van Steenkiste G, Vernemmen I, Demeyere M, Schauvliege S, Decloedt A, van Loon G.Detailed characterization of arrhythmias can be performed by multiple catheter mapping; but this has not yet been explored in horses. Objective: Perform ultrasound-guided multiple catheter mapping of the right heart during sinus rhythm and right and left atrial pacing to identify activation patterns characteristic of the origin of ectopy. Obtain His signals and effective refractory periods (ERP). Methods: Eight healthy adult horses. Methods: Experimental study. Recording catheters were placed at the terminal crest, intervenous tubercle, caudal vena cava, and coronary sinus. Right atrial pacing...
Dufourni A, Demeyere M, Vernemmen I, Van Steenkiste G, Verhaeghe LM, van Loon G, Decloedt A.Administration of N-butylscopolammonium bromide (NBB) with metamizol sodium (NBBM) causes tachycardia and hypertension, and has been associated with accentuated cardiac murmurs. Objective: To evaluate the effect of a pharmacological challenge using NBBM on valvular regurgitation and cardiac murmurs in horses with aortic (AR) and mitral valve regurgitation (MR). Methods: Twenty Warmblood horses with AR and 20 with MR. Methods: Cardiac auscultation and two-dimensional (2D), M-mode, color flow, pulsed wave Doppler flow, and tissue Doppler echocardiography were performed with simultaneous ECG reco...
McCrae P, Spong H, Moorehead J, Pearson W.A smart textile device has been developed for the recording of electrocardiograms (ECGs) in horses; however, the utility of this device for long-duration heart rate variability (HRV) monitoring and detection of physiological arrhythmias is unknown. Therefore, the objective of this study was to validate a smart textile device for HRV over long durations (6 h) in resting horses. ECGs were recorded simultaneously via the Myant Skiin Equine textile device and a reference device (Televet 100) in 12 horses. ECGs were evaluated by a blinded observer for arrhythmias, and HRV metrics were calculated. ...
Zuluaga-Cabrera AM, Barbosa da Costa G, Martinez ID, Arias MP.Colombian Paso horses (CPs) excel in gait competitions due to their endurance, speed, and precision, which demand a high level of cardiorespiratory fitness. However, their training regimes often lack scientific support, and few studies have linked physiological parameters to optimal training zones. This study aimed to estimate the aerobic lactate threshold (LTaer) using mathematical methods and to correlate it with heart rate (HR) zones and blood lactate. Eighteen CPs were evaluated and classified into trained (GT) and untrained (GD) groups. All animals underwent a field-based incremental exer...
Arevalo-Turrubiarte M, Edling CE, Moller-Levet C, Forbes B, Kemp V, Weir J, Marr C, Lewis R, Jeevaratnam K.The initiation and maintenance of atrial fibrillation have been associated with physiological alterations in myocardial sleeves of the pulmonary veins (PVs). Gene expression profiles of the myocardial sleeves of the PVs in healthy (n = 3) and paroxysmal atrial fibrillation (PAF) (n = 6) thoroughbred horses (Equus caballus) were studied. Tissue collected from the left superior PV, adjacent to the left atrium, was analyzed by RNA sequencing. Gene Set Enrichment Analysis demonstrated positive enrichment of gene ontology biological processes related to muscle and endothelial cell development, cell...
A Quarter Horse mare was presented with a history of imidocarb intoxication. During the initial evaluation, the patient presented an initial episode of syncope, in addition to a Grade III/IV diastolic murmur. On the basis of the observed condition, the animal underwent echocardiographic evaluation, in which artifacts were detected and subsequently characterized as air bubbles, restricted to the right cardiac chambers. A diagnosis of venous air embolism resulting from right jugular venocatheterization was made. This is the first reported case of venous air embolism secondary to jugular venocath...
D'el Rey Dantas FT, Forni G, Hallowell G, Castagnetti C, Menchetti L, Romito G, Lanci A, Mariella J, Freccero F.Bodyweight, age and breed influence the echocardiographic assessment of foals. There are no echocardiographic studies in Standardbred neonatal foals. Objective: To describe echocardiographic values for selected variables, evaluate intra- and inter-observer variability and assess cardiac changes in the first 5 days of life in healthy Standardbred neonatal foals. Methods: Prospective observational study. Methods: Fifty-six healthy Standardbred neonatal foals were examined by transthoracic echocardiography using standard right parasternal and subcostal views at three time points: in the first 4...
Nissen SD, Bastrup JA, Haugaard SL, Marion-Knudsen R, Schneider M, Kjeldsen ST, Carstensen H, Hopster-Iversen C, Nattel S, Jepps TA, Buhl R.Horses and humans are among the few mammals susceptible to spontaneous atrial fibrillation (AF), both suffering from high recurrence rates after treatment. Treatment resistance is often attributed to progressive atrial remodeling, but current treatment options fail to effectively address this aspect. Here, we introduce a novel horse model of spontaneous AF to investigate the biological pathway changes in early stages of the disease. Through data-independent acquisition mass spectrometry on biopsies from the right and left atrium and left ventricular chamber of horses with early-stage persisten...
Lutvikadic I, Preldzic D, Floriano D, Hopster K.Pulse pressure (PP) reflects ventricular stroke volume and arterial compliance, but its utility as a marker of cardiac disease in animals is not well established. This study evaluated the association between PP and echocardiographically confirmed cardiac abnormalities in dogs and horses and assessed its potential in pre-anesthetic evaluation. Clinical and echocardiography examination of 20 dogs and 20 horses was sufficient for inter-group comparisons and assignments to a Cardiac group (echocardiographically confirmed cardiac disease) or a Control group (healthy animals). Non-invasive oscillome...
