Читать книгу Manual of Equine Anesthesia and Analgesia - Группа авторов - Страница 126

 Pulse rateNormal rate is similar to the HR (24–50 pulses per minute).Assess the pulse while auscultating the heart to determine whether there are any heart beats without pulse generation (“dropped beats” or “pulse deficit”).

 Pulse rhythmThe normal rhythm is regular. Slight irregularities may occur in the normal horse due to irregularities in the sinus firing (inherent or respiration associated).Rhythm assessment can be difficult when palpating the head arteries if there is head or chewing motions.

 Pulse strengthThe normal pulse pressure is usually moderate in the healthy horse at rest; however, a very mild pulse may be present, especially in the distal limbs, when the horse is at rest.Decreased pulse strength may occur with peripheral vasoconstriction due to inactivity or cool ambient temperatures. May also be due to disease processes resulting in decreased perfusion or decreased cardiac output (e.g. hypovolemia, cardiac disease).Increased pulse strength occurs with increased peripheral vascular demand such as excitement, exercise or transportation. Examples of disease‐associated increases in pulse pressure include laminitis (may have increased pulse pressure in the distal limbs) and aortic valve regurgitation (common in older horses).

 Pulse profileThe normal pulse profile consists of an initial rapid increase in the pulse pressure during systole, followed by a decreased pressure in very early diastole, then another increase in pressure due to the elastic‐recoil properties of the aorta and a subsequent decrease in pressure to baseline. The transition from the initial decrease to the second increase is termed the dicrotic notch. This second increase is typically palpable in the normal horse. An increase in pulse pressure above normal and a loss of the dicrotic notch occurs in horses with aortic valve regurgitation (see below).