An echocardiographic and electrocardiographic study of cardiovascular function in hypothyroid dogs.
Echocardiograms and ECG were obtained for 11 hypothyroid dogs before and after levothyroxine supplementation (0.022 mg/kg of body weight, q 12 h for 64 +/- 12 days). Evidence of impaired left ventricular function was found in the dogs before treatment. A significant decrease in shortening fraction and velocity of circumferential fiber shortening, increase in left ventricular end-systolic diameter, and prolongation of preejection period was noted when comparing measurements before and after levothyroxine supplementation. Amplitude of the P and R waves was significantly higher after treatment than before. It was concluded that changes in cardiac function can be reversed in hypothyroid dogs.
Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison 53706.
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Panciera
D000818:Animals; D002319:Cardiovascular System / Q000503:physiopathology*; D004283:Dog Diseases / Q000503:physiopathology*; D004285:Dogs; D004452:Echocardiography / Q000662:veterinary; D004562:Electrocardiography / Q000662:veterinary; D005260:Female; D007037:Hypothyroidism / Q000150:complications / Q000188:drug therapy / Q000503:physiopathology / Q000662:veterinary*; D013974:Thyroxine / Q000097:blood / Q000627:therapeutic use; D018487:Ventricular Dysfunction, Left / Q000150:complications / Q000662:veterinary
D013974:Thyroxine