Topic:Cardiac Arrhythmias
Cardiac arrhythmias in horses refer to irregularities in the heart's rhythm, which can affect the efficiency of blood circulation. These arrhythmias can result from various factors, including electrolyte imbalances, structural heart changes, or systemic diseases. Common types of arrhythmias in horses include atrial fibrillation, ventricular tachycardia, and premature ventricular contractions. The presence and type of arrhythmia can influence a horse's performance and overall health. Diagnostic tools such as electrocardiography (ECG) are used to identify and assess these irregular heart rhythms. This page compiles peer-reviewed research studies and scholarly articles that explore the mechanisms, diagnosis, and management of cardiac arrhythmias in equine medicine.
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...
Studies into equine electrocardiography and vectorcardiography. IV. Vector distributions in some arrhythmias. The paper describes the changes in P, QRS and T vector orientations in the H plane in the aberrant beats in cases of partial atrioventricular block and premature atrial and ventricular systoles. The sites of possible atrial ectopic foci are discussed in relation to the anatomy of the atrial chambers and the orientation of the P vectors associated with atrial ectopic beats.
Studies into equine electrocardiography and vectorcardiography. 3. Vector distribution in some cardiovascular disorders. 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.
Studies Into Equine Electrocardiography and Vectorcardiography: II. Cardiac Vector Distributions in Apparently Healthy Horses. The paper describes observations on the distributions of the P, QRS and T cardiac vectors in the horizontal plane in 377 apparently healthy horses. The possible usefulness of vectorcardiography in the clinical evaluation of cardiac function is briefly discussed.
Retrospective evaluation of episodic collapse in the horse in a referred population: 25 cases (1995-2009). Episodic collapse in horses has equine welfare and human safety implications. There are, however, no published case series describing this syndrome. Objective: To characterize the cause and outcomes for horses referred for investigation of episodic collapse. Methods: Twenty-five horses referred for investigation of single or multiple episodes of collapse. Methods: Retrospective study. Clinical records from the Dick Vet Equine Hospital, University of Edinburgh from November 1995 to July 2009 were searched using the following keywords: collapse, collapsing, fall, syncope. Collapse was defined as...