RESUMEN
Hyperthyroidism is well known to be associated with cardiovascular manifestations. The authors have noted that patients of well controlled Graves' Disease often pose problems due to intrapoperative cardiovascular instability. Retrospective analysis of 137 case records of patients with Graves' disease (n = 35), toxic nodular goitre (n = 42) and those with euthyroid benign goitre (n = 60) were studied. In Graves' disease cardiovascular instability was found in the form of hypertension (n = 9) associated with tachyarrhythmia (n = 8) and bradycardia (n = 3). The incidence of first 2 of the above mentioned 3 problems was significantly higher in Graves disease (n = 9/35 patients) in contrast to a comparable group of patients with toxic nodular in (3/42 patients; P value 0.05) and euthyroid goiter (2/60 patients; P value < 0.001). Certain parameters such as high T3, T4 at the time of presentation were associated with higher incidence of these complications, in spite of very well controlled thyrotoxicosis. Whether heightened receptor sensitivity to catecholamines and higher renin-angiotensin activation explain these findings in Graves' disease, remains to be ascertained.