Questions Flashcards
Which of the following accurately describes mitral valve prolapse?
- Mitral valve prolapse is a rare cause of mitral regurgitation.
- Mitral valve prolapse is usually caused by Marfan syndrome.
- Most patients with mitral valve prolapse have minimal or no mitral regurgitation
- Most patients with mitral valve prolapse have severe mitral regurgitation that will eventually require surgical management
- Most patients with mitral valve prolapse have minimal or no mitral regurgitation
A patient who was previously healthy presents with acute onset of bilateral blurred vision, dysphagia, and dysarthria, which was preceded by nausea, vomiting, and abdominal pain several hours ago. Over the next two days, she develops symmetrical descending weakness that affects the trunk and upper extremities and begins to show signs of respiratory distress. Physical examination reveals bilateral fixed pupillary dilation and symmetric muscle weakness that does not improve after periods of rest. Which of the following is a known risk factor for this condition?
A. Consumption of food contaminated with Campylobacter jejuni
B. Consumption of improperly canned food
C. Lack of immunization
D. Presence of a thymoma
B. Consumption of impropery canned food
Consumption of improperly canned food is a known risk factor for the development of botulism, which is described in this vignette. Botulism is a rare, life-threatening neuroparalytic condition caused by toxins produced by Clostridium botulinum, a gram-positive, rod-shaped, obligate anaerobic bacteria. The toxin causes a blockade of cholinergic neuromuscular transmission by inhibiting acetylcholine release at the presynaptic neuromuscular junction or by binding to acetylcholine itself. This neuromuscular blockade inhibits transmission of all skeletal and smooth muscle function, in addition to autonomic function. Botulism has three main etiologies including infant botulism, foodborne botulism, and wound botulism.
Which of the following symptoms or signs is found in primary adrenal insufficiency but absent in secondary adrenal insufficiency?
A. Fatigue
B. Hyperpigmentation
C. Malaise
D. Weakness
B. Hyperpigmentation
patients with primary adrenal insufficiency can present abruptly with adrenal crisis or have a vague insidious presentation with fatigue, malaise, and weakness. Other symptoms and signs of primary adrenal insufficiency may include abdominal pain, nausea, vomiting, anorexia, weight loss, hypotension, hyperpigmentation, myalgias, and arthralgias. Additional clinical findings in patients who initially present with adrenal crisis include shock, confusion, and lethargy. Secondary adrenal insufficiency is most commonly due to abrupt withdrawal of glucocorticoids, such as prednisone. Patients present with fatigue, malaise, weakness, and mild hypotension. Hyperpigmentation is not found in patients with secondary adrenal insufficiency because it is a result of excess corticotropin (ACTH) which causes a subsequent elevation in melanocyte stimulating hormone (MSH).
A 25-year-old woman presents to the emergency department with low-grade fever, purpura, and altered mental status. Complete blood count reveals anemia and severe thrombocytopenia. Peripheral blood smear shows schistocytes. Renal function testing reveals mild acute kidney injury. Which of the following describes the pathogenesis of the most likely diagnosis?
A. Aberrant hematopoiesis
B. ADAMTS13 deficiency
C. Infection of the brain parenchyma
D. Shiga toxin from Escherichia coli O157:H7
B. ADAMTS13 deficiency
Thrombotic thrombocytopenic purpura is a condition that occurs due to a deficiency in the ADAMTS13 protease. Physiologically, ADAMTS13 protease cleaves von Willebrand factor (vWF) multimers that are attached to the endothelial surface and are responsible for the formation of platelet microthrombi. With decreased ADAMTS13, these microthrombi form and a consumptive thrombocytopenia develops. Consumptive thrombocytopenia means that the thrombocytopenia was due to the platelets being consumed (used up), which contrasts with thrombocytopenias that are due to the destruction or sequestration of platelets. ADAMTS13 protease levels are reduced due to autoantibodies against ADAMTS13. It is unknown what causes these antibodies to be produced, however, patients typically present with an abrupt presentation and episodes can recur. Patients with thrombotic thrombocytopenic purpura can present with a variety of symptoms. Symptoms include purpura, weakness, abdominal pain, nausea, vomiting, fever, dizziness, and may include neurologic symptoms including focal neurologic deficits, headache, confusion, and altered mental status. Purpura and petechiae often result from thrombocytopenia.
Which of the following tachyarrhythmias has similar risk factors and presents similarly to atrial fibrillation?
A. Atrial flutter
B. Atrioventricular nodal reentry tachycardia
C. Multifocal atrial tachycardiaYour Answer
D. Ventricular tachycardia
A. Atrial Flutter
Atrial flutter shares many of the same risk factors and occurs in similar clinical scenarios as atrial fibrillation. Atrial flutter is a supraventricular tachycardia characterized by rapid atrial contractions at times exceeding > 300 beats per minute. It is much less common than atrial fibrillation and can be divided into typical and atypical forms. Typical atrial flutter involves a reentry circuit through the cavotricuspid isthmus in the right atrium. Atypical atrial flutter does not involve this pathway and is more likely contributable to the presence of scar tissue or intrinsic heart disease. Risk factors include obesity, obstructive sleep apnea, hyperthyroidism, and previous cardiac surgery. Atrial flutter can sometimes occur as a result of antiarrhythmic medications used in atrial fibrillation.
A 42-year-old woman with a history of depression and hypertension presents with a cough and fever. A chest radiograph confirms community-acquired pneumonia. She is currently taking citalopram and lisinopril. She is prescribed clarithromycin. Which of the following adverse effects would you be most concerned for?
A. Diarrhea
B. Nausea
C. QT prolongation
D. Renal failure
C. QT prolongation
clarithromycin needs to be renally adjusted for patients with a creatinine clearance below 30 mL/min. Gastrointestinal side effects are common with macrolide drugs and consist of loose stools, nausea, and abdominal cramping. All macrolides carry the risk of QT prolongation and should not be used in patients with a history of prolonged QT, those taking other drugs that prolong the QT interval (such as citalopram described in the vignette), or those with a history of electrolyte abnormalities. Clarithromycin is a pregnancy category C drug, showing some teratogenic effects in animal studies.
