FMcases 5 - Palpitations (thyroid)

What signs and symptoms are Dehydration and hypovolemia associated with?

Usually acute Tachycardia and orthostatic symptoms such as dizziness

Describe oral radioactive iodine therapy for Grave's Disease?

Very few side effects Iodine destroys most of the overactive thyroid cells and the thyroid gland shrinks in size over a few months Most people develop hypothyroidism and start taking small doses of TH

What is subclinical hypothyroidism? What is the procedure of thyroid replacement therapy for subclinical hypothyroidism?

Subclinical hypothyroidism = high TSH with normal free T4 and T3 levels Management = controversial and should weigh the benefits of replacement = improved cardiac against problems that can accompany the excessive use of levothyroxine = osteoporosis

What are the characteristics of Toxic Diffuse Goiter = Grave's Disease?

- 60-80% of hyperthyroidism. - Autoimmune disease - antibody stimulates TSH receptor and causing excess thyroid hormone - Hypervascularity of the thyroid may result in a bruit or thrill upon auscultation - not present in other etiologies of hyperthyroidism - Exophthalmos - Pretibial myxedema = rare deposition of hyaluronic acid in the dermis and subcutaneous tissues

Characteristics of cardiac arrhythmias

- Commonly cause palpitations, particularly when the heart rate is fast - Dizziness and/or shortness of breath

What is the Follow-up procedure for Radioactive Iodine Treatment?

- Needs to be seen within a few months after treatment to see when to follow her TSH - Discontinue any beta-blockers -ex. propranolol after a few months when patient becomes euthyroid - TSH should be drawn every two to three months until it has stabilized - Time frame can be extended after that to six months or longer - Important to alert the patient to symptoms of hypothyroidism since they will become hypothyroid at some point and so she can be tested earlier if need be

What should always be obtained before initiating radioactive iodine treatment and Why? What other safety precautions must be told to the patient getting RAI?

- Obtain a pregnancy test before initiating radioactive iodine treatment - Patients should not be near pregnant women or young children for several days following RAI because the radioactive iodine is excreted in urine and stool. Fetuses or young children exposed to this could have deleterious effects on their thyroid Ex. closer than 1 meter (40 inches) to children less than three years old for 21 days and recommended that patients flush the toilet twice to be sure the RAI is flushed thoroughly

What are the side effects of RAI therapy?

- Transient soreness of the neck - Brief worsening of symptoms but they should resolve within a few days. - Patients with eye disease may have worsening of it, but this can be prevented with administration of oral steroids after treatment

What are the different characteristics of palpitations and what do they suggest?

1. Fast Heart beat - More likely pathological 2. Hard or increase awareness of heart beat more likely - Strong emotion - anger or fear - Substances containing caffeine or other stimulants 3. Rapid or irregular heart beat more likely - Anxiety - Arrhythmias - although most people with arrhythmias do not complain of palpitations. In addition, it's important to get a history of any heart disease

What is the procedure of thyroid replacement therapy for primary hypothyroidism?

1. Hormone replacement should be initiated in a low dosage - 1.5-1.8 mcg/kg, especially in the elderly and in patients prone to cardiac problems 2. Dosage increased gradually 3. Laboratory values should be monitored 6-8 weeks after any dosage change 4. Once stable dosage is achieved, TSH levels should be checked annually once or twice, especially in older patients 5. After full replacement of thyroxine (T4) using levothyroxine, the addition of triiodothyronine (T3) in a low dosage may be beneficial in some patients who continue to have mood or memory problems or relapse

What are the three treatment options for Grave's Disease?

1. Medication to suppress thyroid hormone production 2. Oral dose of radioactive iodine 3. Surgery

What is the starting dose of thyroxine in primary hypothyroidism?

1.5-1.8 mcg per kilogram

How many patients with palpitations have no etiology?

16%

What are the characteristics of Toxic Nodular Goiter?

5% of hyperthyroidism Thyroid nodules are common, but most are not symptomatic; only 4-5% are cancerous. More common in patients over 40 Multinodular disease more common in older patients Solitary nodules more common in younger patients Can be associated with iodine deficiency

Describe the following for Grave's Disease. % of hyperthyroidism: Proportion in M/F: Peak age incidence: Triggers:

60-80% of hyperthyroidism Women are 5-10 times more likely than men to get it Peak incidence is between ages 40-60. Triggers include stressful life events, high iodine intake, or a recent pregnancy

Describe what characteristics Drug/caffeine abuse have when someone presents with palpations.

Cocaine, methamphetamines and alcohol can cause tachycardia Dilated pupils, Increased energy, increased blood pressure, and erratic behavior

How do you inspect for lid lag?

Ask the patient to follow your finger with their eyes then move your finger slowly from their upper to lower field of vision. In lid lag, the upper eyelid lags behind the upper edge of the iris as the eye moves downward. Be careful when performing this maneuver; if your finger is moved too quickly, the diagnosis may be missed.

What signs and symptoms are aortic stenosis associated with?

Common: Syncope, exertional chest pain and lower extremity edema Rarely cause palpitations

What medication can be given for hyperthyroidism symptomatic relief of adrenergic symptoms - tachycardia, tremor, heat intolerance?

Beta blocker - ex. Propranolol

For each of the following categories, list examples of conditions that can cause palpitations: Cardiovascular Psychiatric Medications Substances Endocrinologic Hematologic Infectious

Cardiovascular: Arrhythmia, cardiomyopathy, hypovolemia Psychiatric: Anxiety, panic attacks Medications: Caffeine, stimulants, theophylline, and albuterol use Substances: Tobacco, caffeine, alcohol intoxication or withdrawal, cocaine Endocrinologic: Hyperthyroidism, pheochromocytoma, hypoglycemia Hematologic: Anemia Infectious: Febrile illness

What are causes of Drug-induced thyroiditis?

Caused by amiodarone, interferon-alpha, interleukin-2, or lithium

Describe what characteristics anxiety and panic disorders have when someone presents with palpations.

Commonly cause palpitations SOB Rarely causes systemic symptoms such as weight loss and changes in stools and menses - distinguishes hyperthyroidism

Describe what characteristics anemia have when someone presents with palpations.

Dec. O2 carrying capacity --> Sinus Tachycardia --> Palpitations Dyspnea and positional dizziness Weight loss is associated with anemia causes malignancy and nutritional deficiencies - vitamin B12, folate Heavy periods Occult bleeding is a rare cause of anemia from GI tract bleeding

How do LDH levels present in hemolytic anemia?

Elevated

What are the characteristics of Thyroiditis? Etiology: Presentation: Most Common forms: Diagnosis: Treatment:

Etiology: Inflammation of the thyroid gland Presentation: - painful, tender w/ infarction, radiation, or trauma - Painless w/ autoimmune conditions, medications, or idiopathic fibrotic process Most common forms: Hashimoto's disease Subacute granulomatous thyroiditis Subacute lymphocytic thyroiditis Postpartum thyroiditis Findings: May have euthyroidism, hyperthyroidism, or hypothyroidism. Diagnosis: - Clinical context and findings - radioactive iodine uptake reduced Treatment: - Symptomatic relief - Restoration to euthyroidism.

When is an ultrasound and MRI used for hyperthyroidism?

Evaluation of thyroid nodules and thyroid enlargement but not hyperthyroidism. Can be used to stratify risk of malignancy and ultrasound Can guide the fine needle aspiration of nodules that are not easily palpated An MRI of the thyroid gland is not necessary to diagnose hyperthyroid disease.

What are the most common manifestations of Graves' ophthalmopathy (eye problems)? What are they related to? Are they bilateral or unilateral? When do they happen? How does treatment of hyperthyroidism affect eye problems?

Eyelid retraction and exophthalmos Primary symptoms related to corneal irritation from eyelid retraction Mostly bilateral, but can be unilateral Mostly hyperthyroid but 10% the eye manifestations can happen when the patient is euthyroid or even hypothyroid Treatment of hyperthyroidism does not affect the eye manifestations

Describe the following for radioiodine therapy (RAI): Indications: Contraindications

Indications: Used to treat Graves' disease, solitary toxic adenoma, multi-nodular goiter, very large goiter in a euthyroid patient Contraindications: Pregnancy and breast feeding are absolute contraindications; Women are advised not to get pregnant for six months after a treatment and men are advised to not father children for four months after treatment; discontinue breast feeding Administration: Patients with severe disease or younger patients may need more than one dose of RAI Patients with eye disease may get worsening of their eye disease with RAI. This can be prevented with administration of oral steroids after treatment. Patients with severe hyperthyroidism should be treated with an antithyroid drug before and after RAI to prevent worsening of disease, and rarely thyroid storm. Choice of treatment: Medication treatment has a lower incidence of permanent hypothyroidism, but higher incidence of relapse and requires frequent monitoring and a prolonged course of therapy.

What is the most common cause of hyperthyroidism in adults and children?

Graves' disease = Toxic diffuse goiter

Why is Gynecomastia seen in Grave's Disease? What proportion of men have it?

Gynecomastia seen in 10-40% of patients with Graves disease Sex hormone binding globulins increased in Graves disease

What are the thyroid conditions that have a High RAIU (>30%) and Low RAIU (<15%)?

High RAIU (>30%): Graves' disease Multi-nodular goiter Toxic solitary nodule TSH-secreting pituitary tumor HCG secreting tumor Low RAIU (<15%): Sub-acute thyroiditis Silent thyroiditis Iodine induced Exogenous L-Thyroxine Struma ovarii Amiodarone

What would be the TSH Level and Serum Free T4 and T3 level (when applicable) for the following conditions? Hypothyroidism Subclinical Hypothyroidism Pituitary adenoma (TSH-producing) or Thyroid hormone resistance Hyperthyroidism Central (or pituitary) hypothyroidism (TSH and/or TRH deficiency) T3 Toxicosis

Hypothyroidism: TSH increased and Serum Free T4 Decreased Subclinical Hypothyroidism: TSH mildly elevated (5-10 mIU/L) and Serum Free T4 Normal Central (or pituitary) hypothyroidism (TSH and/or TRH deficiency): TSH decreased (occ. Normal or slightly elevated) and Serum Free T4 Decreased Hyperthyroidism: TSH decreased and Serum Free T4 Increased Pituitary adenoma (TSH-producing) or Thyroid hormone resistance: TSH inappropriately normal and Serum Free T4 Increased T3 Toxicosis: TSH decreased and Serum Free T4 Normal and Serum T3 Increased

What are causes of goiter?

Lack of iodine Hypothyroidism Hyperthyroidism Nodules Cancer Pregnancy Thyroiditis

What are red flags of Toxic Nodular Goiter?

Male gender Extremes in age (less than 20 or over 65 years old) Rapid growth of nodule Symptoms of local invasion (dysphagia, neck pain, hoarseness) History of radiation to the head or neck Family history of thyroid cancer or polyposis (Gardener's syndrome)

Hyperthyroidism presentation in patients elderly > 70 yo.

Many typical symptoms absent in patients older than age seventy Sinus tachycardia (71%) and/or fatigue (56%) Atrial fibrillation, weight loss, and no other symptoms

Describe the Radioactive iodine uptake (RAIU) test and scan and the normal amount.

Measures the amount and pattern of radioactive iodine taken up by the thyroid in the 24 hours following ingestion of a set dose Normal RAIU uptake is 15-30% of the ingested dose

What is the most commonly used medication for Grave's Disease? Side effects? Duration? Dose?

Methimazole = most commonly used medication Rare < 1% of people have agranulocytosis = bone marrow stops producing white blood cells making vulnerable to serious infections 3 months to suppress thyroid production; improvement noticed in one month; need to stay on medications for several years Appropriate dose fluctuates over time and need routine blood work 1-2x/year for adjustments

What are the symptoms of hypothyroidism?

Mnemonic: C MOMʼS SO TIRED C Constipation M Mental activity slow or Memory loss O Obesity (weight gain with normal appetite) M Muscle Weakness S Slow HR + SOB S Skin and hair become dry + hair loss O Oligomenorrhea T Tired I Intolerance to cold R Raised blood pressure E myxEdema D Depressed

Which cardiac arrhythmias are more common in younger people?

Paroxysmal supraventricular tachycardia

What are the symptoms of hyperthyroidism?

THHYROIDISME T = Tremor H = Heart rate up and Arrhythmia HY = Hypocholesterolemia + Hyperglycemia + Hypercalcemia R = Resorption of bone (osteoporosis) O = Oligomenorrhea & amenorrhea I = Intolerance to heat D =Diarrhea + malabsorption I = Irritability (anxiety, restlessness) and Insomnia S = Sweating and Staring Gaze M = Muscle wasting & weight loss E = Exophthalmos and Emotions (anxiety)

What is used to differentiate Graves' disease from toxic nodular goiter?

Thyroid peroxidase antibodies - Present in 70-80% of Graves' patients

How is Toxic Nodular Goiter evaluated? Which is the best initial test?

Thyroid ultrasound - best initial test Fine needle aspiration (FNA) biopsy of the nodules

What groups have a higher prevalence of hypothyroidism?

Women and elderly