title: The T wave in the V10 precordial electrocardiographic lead is negative in healthy Chihuahua dogs.
abstract: OBJECTIVE
  The T wave polarity in the V10 precordial electrocardiographic (ECG) lead in Chihuahuas is described as positive in the veterinary literature. The aim of this study was to investigate the polarity of the T wave in the V10 precordial ECG lead in clinically healthy Chihuahuas. Our null hypothesis was that healthy Chihuahuas have a negative T wave in V10.
  
  
  METHODS
  In this prospective study, 67 healthy breeder-owned Chihuahuas were used. A physical examination, 10-lead ECG and an echocardiogram were performed on each dog.
  
  
  RESULTS
  No cardio-respiratory abnormalities were revealed in any of the otherwise healthy dogs. Three out of 67 ECGs were of insufficient quality because of baseline artifacts due to movement of the animal. Two other ECGs showed a nearly iso-electric T wave in the V10 lead. The remaining 62 ECGs showed negative T waves in the V10 lead. Right ventricular hypertrophy was excluded with echocardiography in all dogs.
  
  
  CONCLUSIONS
  In contrast to previous reports, we found that healthy Chihuahuas have negative T wave in the V10 precordial ECG lead.
authors.affiliation: Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicine, Utrecht University, Yalelaan 108, 3508 TD Utrecht, The Netherlands. m.dijkstra2@gmail.com
authors.forename: Marieke
authors.initials: M
authors.lastname: Dijkstra
authors.forename: Viktor
authors.initials: V
authors.lastname: Szatmári
mesh_terms: D000818:Animals; D004285:Dogs / Q000502:physiology*; D015150:Echocardiography, Doppler / Q000662:veterinary; D004562:Electrocardiography / Q000379:methods / Q000662:veterinary*; D005260:Female; D006321:Heart / Q000502:physiology; D008297:Male; D011446:Prospective Studies