Echocardiographic values for normal conditioned and unconditioned North American whippets

Abstract

Background: Echocardiographic reference intervals have not been reported for North American whippets, or for whippets that have undergone pet-level athletic training.

Objectives: To develop normal echocardiographic reference intervals for North American whippets and investigate differences in echocardiographic parameters based on athletic conditioning in pet whippets engaged in competitive sports.

Animals: One-hundred healthy North American whippets.

Methods: Dogs were examined at national shows between 2005 and 2009. Echocardiographic reference intervals were constructed and the effect of athletic conditioning on parameters of structure and function was assessed.

Results: Two dimensional, M-mode, Doppler and tissue Doppler reference ranges for healthy North American whippets are presented. Measures of left ventricular (LV) chamber diameter were larger in conditioned whippets (N = 25) and remained significantly larger than in unconditioned whippets (N = 16) when normalized for weight using allometric equations. Calculated LV mass was higher in conditioned dogs than in unconditioned dogs, and this difference persisted when LV mass was normalized by weight. Mitral E velocity was higher in conditioned dogs than in unconditioned dogs, whereas E/A and measures related to systolic function were not different.

Conclusions and clinical importance: Pet whippets in peak athletic condition have larger hearts than do less conditioned whippets, but measures of systolic function are similar. Whippet pet athletes may show eccentric LV hypertrophy at peak condition. Normal values for cardiac size and function in North American whippets might be considered abnormal if population-specific whippet reference intervals are not used in analysis.

Keywords: athletic; canine; dog; echocardiography; reference values.

FIGURE 1

Box and whiskers plot comparing left ventricular diameter in diastole and systole between “conditioned” (n = 25) and “unconditioned” (n = 16) dogs (Mann‐Whitney U test, P < .05). Line: median value, box: 25th and 75th percentile, whiskers: range. The shaded boxes indicate the reference interval for dogs of nonspecified breed within a similar weight range (11.8‐22.7 kg) in *diastole and #systole. LV, left ventricular; LVIDd, left ventricular diameter in diastole; LVIDs, left ventricular diameter in systole; Cond, “conditioned” dogs; Uncond, “unconditioned” dogs.

FIGURE 2

Box and whiskers plot comparing calculated left ventricular mass between “conditioned” (Cond, n = 25) and “unconditioned” (Uncond, n = 16) dogs (Students t test, P < .05). Line: median value, box: 25th and 75th percentile, whiskers: range.