Physiological Values of P-Wave Dispersion in Silesian Breed Horses and Polish Primitive Horses

Abstract

Electrocardiographic examinations were performed on 45 Silesian breed horses (group K, 3-16-year-old, 16 stallions, 29 mares) and on 25 Polish Primitive breed horses (group P, 1.5-19-year-old, two stallions, six geldings, 17 mares). Einthoven and chest leads were used. P-wave dispersion was electronically evaluated. There was no correlation between P-wave dispersion and other ECG parameters, age, sex, body mass, or month of pregnancy. The average value of P-wave dispersion for all horses was 30.77 ms (SD 3.92 ms), however in particular groups it was: in group P -31.89 ms (SD 3.07 ms), and in group K -30.15 ms (SD 4.27 ms). The maximum value of P-wave dispersion in the studied population was 40 ms, in groups P and K -37,6 ms and 40 ms, respectively. The physiological value of P-wave dispersion for the group of horses was below 45 ms.

Assessment of P Wave Indices in Healthy Standardbred Horses

“…In that study, mean (SD) values for P wave duration varied between 131 (14) ms and 158 (19) ms in each of the 12 leads, although Pmin and Pmax were not reported per se. P wave dispersion has not previously been described in SB horses but was reported in one study that examined Polish and Silesian horses [ 40 ]. The mean (SD) Pd reported in that study was slightly lower (30.2 (4.3) ms) compared with this study (43.6 (9.4) ms).…”

“…These differences may be related to differences between breeds, exercise status or differences in the methodology used. In this study, P wave durations were measured over 11 leads, whilst in the study by Michlik et al, only 9 leads were used [ 40 ]. Previous studies in animals have used either six or nine leads to calculate the P wave indices [ 37 , 38 , 39 ].…”

“…We found no significant association between age, sex or bodyweight and P wave duration or dispersion in this study. Michlik et al also found no association between Pd and age, sex or bodyweight in the horses that they studied [ 40 ]. Changes in cardiac size are expected to occur in foals and young growing horses.…”

“…Few studies have reported the use of P wave indices in veterinary medicine [ 37 , 38 , 39 , 40 , 41 , 42 ]. In dogs, Pd has been shown to be significantly increased in those with chronic valvular disease and disturbances of supraventricular conduction [ 38 , 42 ] and was also found to be a useful predictor of arrhythmia recurrence following electrical cardioversion of AF [ 39 ].…”

“…In dogs, Pd has been shown to be significantly increased in those with chronic valvular disease and disturbances of supraventricular conduction [ 38 , 42 ] and was also found to be a useful predictor of arrhythmia recurrence following electrical cardioversion of AF [ 39 ]. In horses, only one study has been performed to determine the values of Pd in healthy Silesian and Polish primitive horses [ 40 ].…”