Echocardiographic evaluation of dogs with dysautonomia.
OBJECTIVE
To describe echocardiographic findings in dogs with dysautonomia.


METHODS
Prospective case series:


METHODS
20 dogs with dysautonomia (13 confirmed during necropsy and 7 with results of antemortem testing [tear production, pilocarpine response test, atropine response test, and ID histamine response] supportive of the diagnosis).


METHODS
Dogs with dysautonomia were evaluated by use of echocardiography, and M-mode measurements were obtained on all dogs. A dobutamine response test was performed on 1 dog, starting at a rate of 1 microg/kg/min and doubling the rate every 15 minutes until fractional shortening (FS) increased to > 2 times the baseline value.


RESULTS
Evidence of systolic dysfunction was detected in 17 of 20 dogs with dysautonomia, as determined on the basis of FS (median, 17.9%; range, 4.0% to 31.1%). Left ventricular internal dimension during diastole or left ventricular internal dimension during systole was enlarged in 4 of 20 and 14 of 20 dogs, respectively. Enlargement of the left atrium or aorta was identified in 3 of 15 and 1 of 15 dogs in which it was measured, respectively. Administration of dobutamine at a rate of 4 microg/kg/min resulted in dramatic improvement in FS (increase from 4% to 17%) in the 1 dog tested.


CONCLUSIONS
Results suggested that echocardiographic evidence of diminished systolic function was common in dogs with dysautonomia. Whether the diminished function was a result of sympathetic denervation or myocardial hibernation was unclear, although myocardial hibernation was more likely.
Harkin
Kenneth R
KR
Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506-5701, USA. harkin@vet.k-state.edu
Bulmer
Barret J
BJ
Biller
David S
DS
D000818:Animals; D004283:Dog Diseases / Q000000981:diagnostic imaging / Q000473:pathology*; D004285:Dogs; D004452:Echocardiography / Q000662:veterinary*; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging / Q000662:veterinary*; D008297:Male; D054969:Primary Dysautonomias / Q000000981:diagnostic imaging / Q000473:pathology / Q000662:veterinary*