Premium
Cardiac changes in experimental hyperthyroidism in dogs
Author(s) -
HOEY A,
PAGE A,
BROWN L,
ATWELL RB
Publication year - 1991
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1991.tb00733.x
Subject(s) - medicine , cats , perfusion , triiodothyronine , endocrinology , cardiology , cardiac hypertrophy , muscle hypertrophy , fractional shortening , heart rate , myocardial hypertrophy , hormone , blood pressure , diastole
SUMMARY Injection of triiodothyronine (T 3 )(1 mg/kg per day subcutaneously for 14 days) to 10 healthy dogs produced a hyperthyroid state characterised by high serum T 3 concentrations, hypokalaemia, hyperactivity, loss of weight, diarrhoea and thirst. Electrocardiographic measurements showed that these dogs had an increase in heart rate of 63 ± 11 beats/min with a significantly increased T wave amplitude without changes in R wave amplitude. Echocardiographic measurements showed no changes in fractional shortening and no evidence of ventricular hypertrophy, in contrast to reports in humans, cats and rats. However, the smooth muscle of the coronary arteries was markedly hypertrophled, which may cause a decrease in myocardial perfusion.