Topic:Cardiovascular Health
Cardiovascular health in horses encompasses the study of the heart and blood vessels, focusing on their structure, function, and associated disorders. The equine cardiovascular system is responsible for the circulation of blood, delivering oxygen and nutrients to tissues, and removing waste products. Research in this area includes the examination of cardiac anatomy, the electrophysiology of the heart, and common cardiovascular conditions such as arrhythmias, valvular diseases, and heart murmurs. Diagnostic tools such as echocardiography, electrocardiography, and cardiac biomarkers are utilized to assess cardiovascular function and detect abnormalities. This page compiles peer-reviewed research studies and scholarly articles that explore the physiological mechanisms, diagnostic approaches, and therapeutic strategies related to cardiovascular health in horses.
Influence of halothane and catecholamines on heart rate and rhythm in the horse. 1. Ventricular ectopic beats were recorded in eight of thirteen conscious horses following the intravenous administration of adrenaline in doses of 3 mug/kg. Following pre-treatment with either atropine sulphate (0.1 mg/kg) or propranolol hydrochloride (0.1 mg/kg), the same dose level of adrenaline failed to produce ventricular ectopic beats.2. Halothane anaesthesia sensitized the equine heart to the arrhythmogenic actions of adrenaline; the incidence and duration of ventricular arrhythmias being greater than in conscious animals. In comparison with the findings in conscious horses, ether anae...
Myocardial atrio-venous junctions and extensions (sleeves) over the pulmonary and caval veins. Anatomical observations in various mammals. The myocardial fibres of the posterior wall of the atrio-venous junctions were examined in 35 large domestic mammals. In the majority of specimens a common pattern in the course and organization of the fibres could be observed. The most obvious features were the following: (1) a main circular fascicle surrounding the pulmonary trunks; (2) fibres encircling the atriovenous junctions; and (3) myocardial sleeves extending along the veins, occasionally as far as the lung. The superior part of the left atrial wall was consistently thicker than the inferior section. Individual variations of this wal...
The cancellation of mirror-image electrocardiograms in the horse. The paper describes the use of a four-electrode cancellation technique, employing a bridge circuit to cancel mirror-image ECGs on the body surface of six horses. The axes joining points at which good cancellations were obtained were plotted on planar diagrams. Evidence is presented which suggests that a considerable proportion of cardiac activity could be regarded as though arising from the activity of a single resultant dipole although there is probably some mobility of the dipole centre during different parts of the cardiac cycle.
Studies on the equine cardiac electric field. I. Body surface potentials. The paper describes the distribution of cardiac potentials on the body surface of four horses. Potentials were recorded at 200 to 300 equallyspaced sites synchronously with a reference lead; they were measured at 10 msec. instants of time, and were plotted on diagrams. While some evidence of multiple dipolar activity occurred during each part of the cardiac cycle, the majority of potentials arose as if from a single resultant dipole.
The influence of suxamethonium on cardiovascular and respiratory function in the anaesthetized horse. 1. In horses anaesthetized with halothane the intravenous administration of suxamethonium chloride, at a dose level of 0.2 mg/kg, produced a short-lived period of hypoventilation, which was associated with increases in arterial blood PCO(2) levels and in plasma concentrations of bicarbonate, sodium and potassium ions, and reductions in arterial blood pH and PO(2) values.2. The respiratory depressant action of suxamethonium chloride 0.2 mg/kg was accompanied by increases in blood pressure and heart rate. Doses of suxamethonium chloride 0.4 mg/kg produced similar but quantitatively greater chang...
Sampling of equine pulmonary vein blood. A technique involving thoracotomy for the implantation of polythene catheters through the left atrium into the pulmonary veins has been used in 2 ponies. In both animals the catheters enabled blood samples to be obtained from the pulmonary veins for more than 5 weeks. Post mortem examination after termination of the experiment showed the procedure and catheters produced the minimum of adverse effects.