title: [Comparison of different electrocardiographic techniques for the detection of arrhythmias in horses].
abstract: OBJECTIVE
  The aim of the study was to extend the range of the electrocardiographic examination in horses, evaluating the practicability of special electrocardiographic techniques (exercise- and Holter-ECG) and comparing these with more common techniques (resting-ECG) in equine medicine.
  
  
  METHODS
  Electrocardiographic examination (resting-ECG for 1 minute, exercise-ECG and Holter-ECG) was performed in 20 horses without any clinical or echocardiographic findings and in 80 patients with abnormal findings (valvular regurgitation and/or atrial fibrillation).
  
  
  RESULTS
  In comparison with the resting-ECG, the exercise-ECG demonstrated more atrial and ventricular premature beats, while the Holter-ECG had a higher detection rate of 2nd degree atrioventricular or sinuatrial blocks, and of ventricular and atrial premature depolarisations (p < 0.001). In comparison to the exercise-ECG, the Holter-ECG registered more 2nd degree atrioventricular blocks (p < 0.001) and ventricular (p < 0.001) or atrial premature contractions (p < 0.01). Atrial fibrillation was detected in every recorded ECG-type, but Holter-ECG provided additional information. Three of 16 horses with atrial fibrillation had R-on-T-episodes during Holter-monitoring. In addition to more common findings in the ECG, Holter-monitoring detected a 2nd degree atrioventricular block associated with an adjacent ventricular escape beat in a horse without any clinical or echocardiographic findings. An accelerated idioventricular rhythm was identified in a horse without any clinical or echocardiographic findings and in a horse with mitral valve insufficiency.
  
  
  CONCLUSIONS
  The Holter-ECG is a useful tool in the evaluation of heart disease and could supply additional information when compared to the usual diagnostic electrocardiographic procedures used in horses. Exercise-ECG should not be replaced by Holter-ECG, however, Holter-EGC can provide additional diagnostic value.
authors.affiliation: Frauke Uhlendorf, Klinik für Pferde, Stiftung Tierärztliche Hochschule Hannover, Bünteweg 9, 30559 Hannover, E-Mail: frauke.uhlendorf@tiho-hannover.de.
authors.forename: F
authors.initials: F
authors.lastname: Uhlendorf
authors.forename: H
authors.initials: H
authors.lastname: Gehlen
authors.forename: P
authors.initials: P
authors.lastname: Stadler
mesh_terms: D000818:Animals; D001281:Atrial Fibrillation / Q000175:diagnosis / Q000662:veterinary*; D015716:Electrocardiography, Ambulatory / Q000379:methods / Q000662:veterinary*; D006349:Heart Valve Diseases / Q000175:diagnosis / Q000662:veterinary*; D006734:Horse Diseases / Q000175:diagnosis* / Q000503:physiopathology; D006736:Horses
keywords: Holter-ECG; atrial fibrillation; exercise-ECG; resting-ECG; valvular regurgitation