Hyperthyroidism Flashcards
what are the cardiac symptoms of hyperthyroidism?
HTN
tachycardia
increased contractility (increased CO)
what are the sequelae of the cardiac symptoms of hyperthyroidism?
atrial fibrillation
high output cardiac failure
what ocular symptoms are specific to graves disease?
proptosis
opthalmoplegia
periorbital edema
hyperthyroidism: pathophysiology
increased thyroid hormone synthesis
- primary - inherent thyroid problem
- secondary - stimulated by TSH
innapropriate leakage of premade T4
causes of hyperthyroidism?
graves disease autonomous nodule(s) subacute thyroiditis iodine-induced hyperthyroidism TSH-producing pituitary adenoma HCG mediated
what are the lab values for hyperthyroidism?
low TSH +/- increased FT4 or FT3
graves disease: pathophysiology
antibodies to TSH receptors stimulate growth and hormone production - continuous stimulation of gland to make new hormone
what test is typically best for graves disease?
thyroid uptake and scan
what would you NOT expect the uptake to be in graves disease? what does the scan look like?
low
scan - homogeneous
generally speaking, what are the treatment strategies for treatment of graves disease?
- slow down new hormone synthesis
- remove source of thyroid hormone
antithyroid medications: MOA
what are the antithyroid medications?
temporary treatment to inhibit organification of iodine to iodotyrosine, and coupling
propylthiouracil
methimazole
what are the adverse effects of the antithyroid drugs?
hepatitis
agranulocytosis
what is the ultimate goal of radioactive thyroid ablation?
render patient hypothyroid (patient is then given levothyroxine for life)
why treat with SSKI a week prior to surgery?
- trying to decrease T4 concentration
- also decreases vascularity
autonomously functioning nodules: pathophysiology
hyperplasia of follicular cells, overproduction of T4 independent of TSH
what do autonomously functioning nodules look like on uptake and scan?
focal areas of hyperactivity, while normal thyroid is suppressed
what is the preferred treatment for hot nodules? why?
radioactive ablation - preferentially targets hyperfunctioning areas
thyroiditis: pathophysiology
leakage of preformed hormone (not a condition of thyroid hormone synthesis)
what is the etiology of thyroiditis?
viral, radiation, iodine exposure, postpartum
what is the uptake for thyroiditis? why? what is the appearance?
low - not making new hormone
patchy appearance
what is the treatment for thyroiditis?
mainly supportive
NSAIDs if there is some pain
what is the natural history of thyroiditis in terms of hormone levels?
hyperthyroid - euthyroid - hypothyroid
why dont antithyroids work very well with thyroiditis?
antithyroids work by slowing down hormone production, but in thyroiditis the production is already slow
iodine induced hyperthyroidism: pathophysiology
more substrate - making more T4 (think jod basedow)
what drug can cause iodine induced hyperthyroidism? how?
amiodarone
increased synthesis
thyroiditis
what are the diagnostic challenges to amiodarone induced hyperthyroidism?
thyroid uptake and scan
- competitive binding between I123 and iodine, uptake is invariably low
- US may show increased vascularity in type 1
what are the therapeutic challenges to amiodarone induced hyperthyroidism?
antithyroids?
I131?
glucocorticoids - prednisone for type 2
what are the clinical features of a TSH producing pituitary adenoma?
hyperthyroidism
goiter
+/- visual fields defects
what is HCG mediated hyperthyroidism?
- in pregnancy, HCG levels increase exponentially, peaks at week 12
- HCG stimulates thyroid
what is the treatment for thyroid storm?
- supportive - sedation, fluids, oxygen, cooling
- treat precipitating cause
- beta blockers
- glucocorticoids
- antithyroids
- iodine
what is considered the etiology of euthyroid sick syndrome?
body’s response to major illness (not hyperthyroidism)
