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88 Cards in this Set
- Front
- Back
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What systems have conditions that can cause palpitations? |
- Cardiovascular - Psychiatric - Medications / substances - Endocrinologic - Hematologic - Infectious |
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What are some cardiovascular conditions that can cause palpitations? |
- Arrhythmia - Cardiomyopathy - Hypovolemia |
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What are some psychiatric conditions that can cause palpitations? |
- Anxiety - Panic attacks |
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What are some medications / substances that can cause palpitations? |
- Caffeine - Stimulants - Theophylline - Albuterol - Tobacco - Alcohol intoxication / withdrawal - Cocaine |
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What are some endocrinologic conditions that can cause palpitations? |
- Hyperthyroidism - Pheochromocytoma - Hypoglycemia |
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What are some hematologic conditions that can cause palpitations? |
Anemia |
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What are some infectious conditions that can cause palpitations? |
Febrile illness |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What are the top 5 differential diagnoses? |
- Hyperthyroidism - Cardiac arrhythmia - Anxiety / panic disorder - Anemia - Drug / caffeine abuse |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What is the rationale for why hyperthyroidism could explain her symptoms? |
- Increase in thyroid hormone increases the metabolism and may cause weight loss, frequent loose stools, and light periods - Other effects include an increased HR - This seems the most likely at this point because it explains all of her symptoms |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What is the rationale for why cardiac arrhythmia could explain her symptoms? |
- Commonly causes palpitations, particularly when the HR is fast - Can be associated with dizziness and/or SOB - Some, like paroxysmal supra ventricular tachycardia, are more common in young people - NOT associated with systemic symptoms like weight loss, oligomenorrhea, or loose stools
- Presence of systemic symptoms makes this less likely as the sole explanation |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What is the rationale for why anxiety or panic disorder could explain her symptoms? |
- Commonly cause palpitations and can be associated with SOB - Anxiety and hyperthyroidism can be difficult to distinguish because they both can cause tachycardia, tremulousness, irritability, weakness, and fatigue - In anxiety, however, systemic symptoms such as weight loss and changes in stools and menses are rare |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What is the rationale for why anemia could explain her symptoms? |
- Can be associated with palpitations because of sinus tachycardia due to reduced oxygen carrying capacity in the blood (anemia can also cause dyspnea via this mechanism) - Patients with anemia severe enough to cause tachycardia typically report positional dizziness which is not present here - Several causes of anemia are associated with weight loss including nutritional deficiencies (vitamin B12, folate) and malignancy - A common source of anemia in menstruating women is heavy periods, which is not present here - In rare cases occult bleeding can be present and cause anemia |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What is the rationale for why drug / caffeine abuse could explain her symptoms? |
- Can cause palpitations - Intoxication with substances such as cocaine, methamphetamines, and even alcohol can cause tachycardia - Signs such as dilated pupils, increased energy, increased BP, and erratic behavior all suggest intoxication
- She has none of these and substance abuse seems unlikely, although would need to be considered if no other cause was found - She reports fairly low caffeine intake, but keep in mind patients may overlook other sources of caffeine that coffee, tea, and soda |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What is the rationale for why aortic stenosis is an unlikely cause of her symptoms? |
It can rarely cause palpitations. It most commonly causes syncope, exertional chest pain, and lower extremity edema, which are all absent here. |
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30-year old woman with several weeks of palpitations with associated mild dyspnea. She also notes a 5-lb non-intentional weight loss, oligomenorrhea, increased sweating and loose stools during this period. She reports minimal caffeine intake and denies use of drugs or alcohol, but repots high levels of work-related stress.
What is the rationale for why dehydration and hypovolemia are an unlikely cause of her symptoms? |
Can cause tachycardia. However this is usually an acute presentation and is also associated with orthostatic symptoms such as dizziness. |
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What are the signs / symptoms of hyperthyroidism? |
For patients <50 years, most common: - Heat intolerance - Tachycardia - Fatigue - Weight loss - Tremor - Increased sweating - Exertional dyspnea - Diarrhea - Light periods - Depression (less common) - Hyperreflexia (less common) |
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What causes tachycardia in patients with hyperthyroidism? |
Increased adrenergic tone and heightened conduction |
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What causes weight loss in patients with hyperthyroidism? |
Increased calorigenesis and gut motility causing hyperdefecation and malabsorption |
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What causes exertional dyspnea in patients with hyperthyroidism? |
O2 consumption, CO2 production, and respiratory muscle weakness |
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At what age are many of the typical symptoms of hyperthyroidism absent? |
Patients >70 years |
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What are typical features of hyperthyroidism in patients >70 years? |
- Sinus tachycardia - Fatigue - Atrial fibrillation - Weight loss |
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What exam maneuvers should you do in a patient you suspect of having hyperthyroidism? |
- Lid lag test - Assess for exophthalmos - Thyroid exam (have patient swallow) - Brisk reflexes |
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How do you assess 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. |
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What is exopthalmos? |
AKA Proptosis = forward projection or bulging of the eye out of the orbit; most commonly seen in Grave's disease and can be either bilateral or unilateral |
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What is the differential diagnosis for an enlarged thyroid? |
- Lack of iodine - Hypothyroidism - Hyperthyroidism - Nodules - Thyroid cancer - Pregnancy - Thyroiditis |
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What is the most common cause of a goiter? |
Lack of iodine |
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What is the most common, yet easily preventable, cause of developmental delay and mental retardation in the world? |
Lack of iodine |
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What areas of the world are most affected by lack of iodine? |
Northern Africa and Pakistan |
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What is clonus? |
A series of abnormal reflex movements of the foot induced by sudden dorsiflexion causing alternate contraction and relaxation of the gastrocnemius and soleus muscles |
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What is the most common cause of hyperthyroidism in adults and children? |
Toxic diffuse goiter (Graves' disease) = 60-80% of hyperthyroidism |
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What causes Graves' disease? |
Auto-immune disease caused by an antibody that acts at the TSH receptor and stimulates the gland to synthesize and secrete excess thyroid hormone |
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What exam findings are specific to Graves' disease? |
- Thyroid bruit / thrill - due to hypervascularity of the thyroid - Exophthalmos - Pretibial myxedema - due to deposition of hyaluronic acid in dermis and subcutaneous tissue |
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What causes pretribial myxedema? What is it associated with? |
Rare finding, most common in Graves' disease - Caused by deposition of hyaluronic acid in dermis and subcutaneous tissues |
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What causes a thyroid bruit or thrill? What is it associated with? |
Present in Graves' disease and not other etiologies of hyperthyroidism - Caused by hypervascularity of the thyroid |
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What are the characteristics of thyroid nodules? |
- Cause about 5% of cases of hyperthyroidism - Nodules are common, but most are asymptomatic - Only 4-5% are cancerous - More common in patients >40 years; these older patients are more likely to have multi nodular disease - Solitary nodules are more common in younger patients and can be associated with iodine deficiency |
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How does a multi nodular thyroid compare to a solitary nodule of the thyroid? |
- Multinodular is more common in older patients (>40 years) - Solitary nodules are more common in younger patients; may be associated with iodine deficiency |
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What happens in thyroiditis? |
Thyroid hormones leak from an inflamed thyroid |
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When is thyroiditis more common? |
After a viral illness or pregnancy |
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What can cause iodine excess? What does this lead to? |
Excessive iodine can occur through diet or a medication, such as amiodarone
This can induce thyroiditis / drug-induced hyperthyroidism |
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What studies should you order in a patient with palpitations you suspect of having hyperthyroidism? |
- EKG (check for arrhythmia) - TSH / T4 (check for hyperthyroidism) - CBC (check for anemia) |
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Why do you need to order a T4 level and not just when evaluating a person for hyperthyroidism? |
TSH is usually sufficient to make a diagnosis of both hyperthyroid and hypothyroid, but there are some unusual causes of low TSH due to primary pituitary pathology
In those cases the TSH does not reflect the circulating thyroid level. In those cases the T4 level is low, because the pituitary is not stimulating the gland to make thyroxine |
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What does the hypothalamus release related to thyroid hormone? |
Thyrotropin Releasing Hormone (TRH) |
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What is the source and action of Thyrotropin Releasing Hormone (TRH)? |
- Source: Hypothalamus - Action: stimulates the pituitary to produce and release TSH |
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What is the source and action of Thyroid Stimulating Hormone (TSH)? |
- Source: Pituitary - Action: Stimulate the thyroid to make thyroid hormone (T3 and T4) |
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What happens when thyroid hormone levels are high? |
Presence of excess thyroid hormone exerts negative feedback on the hypothalamus and anterior pituitary, suppressing release of both TRH from hypothalamus and TSH from anterior pituitary gland |
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What happens when thyroid hormone levels are low? |
Hypothalamus releases thyrotropin releasing hormone (TRH). TRH stimulates the pituitary to produce TSH. TSH, in turn, stimulates the thyroid to produce thyroid hormones until levels in the blood return to normal. |
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What condition is indicated by increased TSH and decreased serum free T4? |
Hypothyroidism |
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What condition is indicated by mildly elevated TSH (5-10 mIU/L) and normal serum free T4? |
Subclinical hypothyroidism |
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What condition is indicated by inappropriately normal TSH and increased serum free T4? |
Pituitary adenoma (TSH-producing) or Thyroid hormone resistance |
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What condition is indicated by decreased TSH and increased serum free T4? |
Hyperthyroidism |
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What condition is indicated by decreased (occasionally normal or slightly elevated) TSH and decreased serum free T4? |
Central (or pituitary) hypothyroidism (TSH and/or TRH deficiency) |
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What condition is indicated by decreased TSH and normal serum free T4 with increased serum T3? |
T3 Toxicosis |
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Once you have determined a patient has hyperthyroidism, how should you proceed to determine the etiology? |
- Radioactive iodine uptake (RAIU) test and scan - Thyroid antibody test |
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What is the purpose of the radioactive iodine uptake (RAIU) test / scan? |
Measures the amount and pattern of radioactive iodine taken up by the thyroid in the 24 hours following ingestion of a set dose. |
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What is a normal RAIU test / scan result? |
15-30%
(High RAIU >30%; Low RAIU <15%) |
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How can you differentiate the types of hyperthyroidism? |
High RAIU (>30%) Low RAIU (<15%) |
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What are the causes of hyperthyroidism with a high RAIU (>30%)? |
- Graves' disease - Multi-nodular goiter - Toxic solitary nodule - TSH-secreting pituitary tumor - HCG secreting tumor |
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What are the causes of hyperthyroidism with a low RAIU (<!5%)? |
- Sub-acute thyroiditis - Silent thyroiditis - Iodine induced - Exogenous L-thyroxine - Struma ovarii - Amiodarone |
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What kind of antibodies are present in Graves' disease (how often)? |
Thyroid peroxidase antibodies (70-80% of Graves' disease patients)
TSH receptor antibodies |
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When would you utilize a thyroid ultrasound? |
To evaluate thyroid nodules and thyroid enlargement, but not hyperthyroidism
Can be used to stratify risk of malignancy, guide the fine needle aspiration of nodules that are not easily palpated |
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How does the incidence of Graves' disease differ between the genders? |
Women are 5-10x more likely to get it |
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When is the peak incidence of Graves' disease? |
Ages 40-60 |
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What are the triggers of Graves' disease? |
- Stressful life events - High iodine intake - Recent pregnancy |
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What are the manifestations of eye involvement in Graves' disease? |
- Most common manifestation of Graves' ophthalmopathy (eye problems) are eyelid retractions and exophthalmos - Primary symptoms are related to corneal irritation from eyelid retraction - While most of the time eye signs are bilateral, they can be unilateral - 50% have some eye involvement by MRI, only 20-30% are clinically relevant - In up to 10% these manifestations the patient is euthyroid or even hypothyroid - Treatment does not affect eye manifestations; some may get worsening with tx by radioactive iodine |
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What are the most common manifestations of Graves' ophthalmopathy? |
- Eyelid retraction - Exophthalmos - Most eye symptoms are bilateral, but they can be unilateral - Primary symptoms are related to corneal irritation from eyelid retraction |
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How often do patients with Graves' disease have eye involvement? |
- 50% by MRI - 20-30% clinically relevant |
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Are eye manifestations of Graves' disease worse with higher thyroid hormone? |
Not necessarily; eye manifestations can occur when patient is euthyroid or even hypothyroid
Also, treatment with radioactive iodine can actually cause worsening of symptomatology |
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What are the treatment options for Graves' disease? |
- Medications to suppress thyroid hormone production - Oral dose of radioactive iodine - Surgery |
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What medications can suppress thyroid hormone production in Graves' disease? |
Methimazole |
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What is the effect of Methimazole? |
Most commonly used medication to suppress thyroid hormone |
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What are the possible side effects of methimazole? |
Rare, but less than 1% have a serious side effect known as AGRANULOCYTOSIS (BM stops producing WBCs --> vulnerable to infection) |
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How long does it take to suppress thyroid function with methimazole? How long until patients note improvement in symptoms? |
- 3 months to suppress thyroid production - 1 month until patients start to notice improvement |
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How long do patients need to take methimazole for Graves' disease? |
Most need to stay on for several years; >1/2 of patients return to hyperthyroidism if they stop |
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How does the required dosing of methimazole change? |
Appropriate dose of methimazole fluctuates over time and people need to come in for blood work often for adjustments |
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What is the alternative to thyroid hormone suppression for Graves' disease, especially in the U.S.? |
Oral dose of radioactive iodine |
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What are the effects of radioactive iodine for Graves' disease? |
- Iodine concentrated in the thyroid; very few side effects - Iodine destroys most of the overactive thyroid cells over the course of a few months - Level of thyroid hormone falls and thyroid gland shrinks in size |
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What are the implications of having radioactive iodine therapy for Graves' disease? |
Eventually most people who have this treatment start having too little thyroid in their blood stream so that they need to start taking small doses of thyroid hormone to replace it |
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How do you manage a patient with low thyroid following radioactive iodine treatment for Graves' disease? |
Once you find a dose where the patient feels normal and the TSH is in the normal range, you can draw blood levels 1-2x/year
The dose of thyroid replacement usually stays about the same |
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What is the most popular treatment option for Graves' disease in U.S.? How popular? |
Radioactive iodine is given to 70% of patients |
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What is the most popular treatment option for Graves' disease in Europe? |
More get medical suppression (methimazole) |
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What needs to be done prior to giving radioactive iodine treatment for Graves' disease? |
- Pregnancy test - Pt's should not be near pregnant women or young children for several days because the radioactive iodine is excreted in urine and stool - Fetuses or young children exposed to this could have deleterious effects on their thyroid |
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What are the side effects of radioactive iodine treatment for Graves' disease? |
- Transient soreness of the neck - Brief worsening of symptoms, but they should resolve within days - People with ophthalmopathy can have worsening |
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How should you follow-up on a patient after they have received radioactive iodine treatment? |
- Patient needs to be seen within a few months to see when to discontinue propranolol (if prescribed) and to follow her TSH - Patient should have her TSH drawn every 2-3 months until it has stabilized (following stabilization, time frame can be extended to 6 months or longer) |
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What are the common symptoms of hypothyroidism? |
- Weight gain - Cold intolerance - Pedal edema - Heavy periods - Fatigue |
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How do you treat a patient with hypothyroidism? |
Start with a low dose of thyroxine (1.5-1.8 mcg/kg) in primary hypothyroidism (e.g., s/p radioactive iodine treatment) |
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After starting a low dose of thyroxine, when should you recheck the TSH? |
6 weeks |
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When can you stop checking the TSH every 6 weeks? |
When a stable TSH has been achieved in primary hypothyroidism; can be checked 1-2x annually |
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Does every patient become hypothyroid after radioactive iodine therapy? |
No, some have enough thyroid left to relapse; occasionally they will need a second treatment of radioactive iodine |
