A 25-year-old woman comes to the physician with a 3-month history of weight loss, irritability, insomnia, and palpitations. Her medical history is insignificant. She is not currently taking any medications. The patient does not use tobacco, alcohol, or illicit drugs. Blood pressure is 155/70 mm Hg and pulse is 110/min. Physical examination shows lid retraction, warm skin, and fine tremor of the hands. Which of the following is the most likely cause of this patient's hypertension?

Question

A 25-year-old woman comes to the physician with a 3-month history of weight loss, irritability, insomnia, and palpitations.  Her medical history is insignificant.  She is not currently taking any medications.  The patient does not use tobacco, alcohol, or illicit drugs.  Blood pressure is 155/70 mm Hg and pulse is 110/min.  Physical examination shows lid retraction, warm skin, and fine tremor of the hands.  Which of the following is the most likely cause of this patient's hypertension?

Quizplus · Accepted Answer

11ec25c8_d3ba_2019_bc81_05a13bca3ea8_MD0003_00 This patient with weight loss, tachycardia, tremor, and lid retraction has common features of thyrotoxicosis. Thyrotoxicosis can produce a number of cardiovascular complications directly through the effects of triiodothyronine (T3) on cardiac myocytes and blood vessels, as well as indirectly by increasing sensitivity to circulating catecholamines. Generally, thyrotoxicosis causes positive inotropic and chronotropic effects, leading to a hyperdynamic cardiovascular state characterized by tachycardia, systolic hypertension, and widened pulse pressure. Arrhythmias are common and may include sinus tachycardia, atrial fibrillation/flutter, and atrial and ventricular ectopy. Increased oxygen demand in thyrotoxicosis is due to increased cardiac output and increased systemic oxygen consumption; this can lead to anginal symptoms in patients with underlying coronary atherosclerosis. Angina may also occur due to coronary vasospasm (especially in young female patients). Thyrotoxicosis may also cause new-onset heart failure or decompensation of preexisting heart failure. (Choice A) Long-standing hypercalcemia, as seen in hyperparathyroidism, is associated with hypertension, possibly due to effects on contractility and arterial compliance. Thyrotoxicosis may cause hypercalcemia due to increased bone turnover, but this is generally mild and is not a significant contributor to systemic hypertension. (Choice C) Systemic hypertension may be seen in both hyperthyroidism and hypothyroidism. Hyperthyroidism causes a decrease in systemic vascular resistance, but blood pressure (primarily systolic) rises due to positive inotropic and chronotropic effects. In contrast, hypothyroidism causes hypertension due to an increase in systemic vascular resistance. (Choice D) Thyrotoxicosis causes increased sensitivity to catecholamines due to increased expression of beta-1 adrenergic receptors as well as changes in proteins controlling post beta-1 adrenergic receptor activity. However, T3 does not stimulate catecholamine production. (Choice E) Nocturnal hypoventilation is a common cause of secondary hypertension that is seen in obstructive sleep apnea (OSA). Patients with OSA may experience disordered sleep, irritability, and palpitations. However, weight loss, lid retraction, and tremor are more suggestive of thyrotoxicosis. Educational objective: Systolic hypertension in thyrotoxicosis is caused by hyperdynamic circulation resulting from increased myocardial contractility and heart rate. References: Thyroid hormone and the cardiovascular system. (http://www.ncbi.nlm.nih.gov/pubmed/22443974)

A 25-Year-Old Woman Comes to the Physician with a 3-Month