EXAM #1: HYPERTHYROID Flashcards
What are the cardiac sequelae of hyperthyroidism?
1) A-fib
2) High-output failure
What is Graves’ dermopathy?
Thickening of the skin in the setting of hyperthyroidism
What changes in the eyes are specific to Graves’ disease?
1) Proptosis
2) Ophthalmoplegia*
3) Periorbital edema
*Can’t look in certain directions, can lead to diplopia
What are the three major pathophysiologic mechanisms of hyperthyroidism?
1) Increased thyroid hormone synthesis
- Primary (thyroid)
- Secondary (TSH)
2) Inappropriate LEAK of T4
What are the major etiologies of hyperthyroidism?
1) Graves’ Disease
2) Autonomous nodules
3) Subacute thyroiditis
4) Iodine-induced
5) TSH-producing adenoma
6) HCG-mediated (pregnancy)
What are the TSH and FT4 levels in hyperthyroidism?
- Low TSH
- High FT4 (normal is subclinical)
What antibody test is used in the diagnosis of hyperthyroidism?
TSI
What is the most common cause of hyperthyroidism?
Graves’ Disease
What causes Graves’ Disease?
Autoimmune antibodies to TSH receptors
- TRAb
- TSIg
What are the “extra” manifestations of Graves’ disease compared to hyperthyroidism?
1) Graves’ Ophthalmopathy
- Inflammation
- GAG
- Edema
- Adipogenesis
- Extraocular muscle hypertrophy
2) Dermopathy
What is the direct cause of Graves’ Ophthalmopathy?
Antibodies
What is the main test used to diagnose Graves’ Disease? What is the expected outcome?
Radionuclear uptake and scan
- Uptake will be normal/high
- Homogenous scan
What is the treatment for Graves’ Disease?
1) Symptomatic: beta-blockers, steroids
2) Specific
What is the MOA of the antithyroid drugs?
Inhibits organification and coupling
What drugs are “antithyroid?”
PTU
Methimazole
What adverse is associated with the antithyroids, especially PTU?
Hepatitis
How long are the antithyroid medications typically given?
2 years
What is used for a radioactive ablation in Graves’ Disease?
I131 (different from what is used for the diagnostic test)
*Permanent but can take 4 weeks to 6 months
What do you do when a patient becomes hypothyroid s/p radioactive thyroid ablation?
Levothyroxine
Why would you treat a patient with iodine for a week prior to surgery?
Decreased T4 and vascularity
*Utilizes the Wolff Chiakoff Phenomenon
What is an autonomously functioning thyroid nodule?
Hot nodule with hyperplasia of follicular cells
*There is overproduction of T4 INDEPENDENT of TSH
How will the uptake and scan appear in autonomously functioning thyroid nodule?
- Normal to high uptake
- Focal hyperactivity i.e. NOT homogenous
What is the preferred treatment for autonomously functioning thyroid nodule?
Radioactive ablation
*Only the focal hot-spots will uptake the radioactive material
How does the outcome of radioablation for autonomously functioning thyroid nodule differ from Graves’ Disease?
Much less likely to cause hypothyroid
What is the underlying pathology in thyroiditis?
Inflammation of thyroid tissue leading to leakage of preformed hormone
What will a radionuclear scan appear in thyroiditis?
Low uptake
What is the treatment for thyroiditis?
Supportive care
What should you be sure to check after a patient with thyroiditis transitions to euthyroid?
TSH/T4 to ensure they don’t develop hypothyroid
When is iodine-induced hyperthyroidism commonly seen?
Amiodarone*
*Utilizes the Jod Basedow effect
What are the types of amiodarone induced hyperthyroid?
Type 1 AIH= increased synthesis
Type 2 AIH= thyroiditis
How can you diagnose Type 1 vs 2 AIH?
Ultrasound will show increased muscularity in Type 1
How can AIH be treated?
1) Glucocorticoids i.e. prednisone
2) Surgery
What labs are seen in a TSH-producing pituitary adenoma? What name is given to this condition?
- Increased T4
- Increased TSH
This is SECONDARY hyperthyroidism
What clinical features are associated with TSH-producing pituitary adenomas?
1) Hyperthyroidism
2) Goiter
3) Visual field defects
What is the treatment for a TSH-producing pituitary adenoma?
1) Octreotide
2) Transphenodial resection
Why is hyperthyroid seen in pregnancy?
HCG stimulates thyroid
What is the treatment for HCG-mediated hyperthyroidism in pregnancy, IF T4 is high?
First trimester= PTU
2nd-3rd= Methimazole
*Note if T4 is normal, no treatment necessary
What typically triggers Thyroid Storm?
1) Omission of anti-thyroid drug
2) Surgery, MI, CVA
*In patient with underlying hyperthyroidism
What is the specific treatment algorithm for Thyroid Storm?
1) Beta-blocker
2) Glucocorticoids
3) Antithyroids
4) Iodine
What is euthyroid sick syndrome?
Low serum levels of thyroid hormones in clinically euthyroid patients with nonthyroidal systemic illness
*TSH is also low
What is the treatment for euthyroid sick syndrome?
None–treatment is not necessary
