Question 1
A 38-year-old man has had increasing dyspnea with peripheral edema, worsening for the past two years. On physical examination he has diffuse crackles auscultated in both lungs. A chest radiograph shows that the heart nearly fills the chest. A chest CT scan demonstrates a 10 cm mass involving the right ventricle that appears to have areas of hemorrhage and necrosis within it. Which of the following neoplasms is this man most likely to have?
A Rhabdomyosarcoma
B Mesothelioma
C Myxoma
D Angiosarcoma
E Papillary fibroelastoma
F Kaposi sarcoma
G Rhabdomyoma
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(D) CORRECT. This is a rare neoplasm (all cardiac neoplasms are rare) but the size alone suggests a malignancy.
(A) Incorrect. This is a very rare malignancy that typically appears in soft tissues.
(B) Incorrect. There is a very rare neoplasm called a polycystic tumor of the AV node that has mesothelial differentiation. Though small, it can lead to arrhythmias.
(C) Incorrect. This neoplasm is usually found in one of the atria. It can produce obstruction of the AV valve (a 'ball-valve' effect).
(E) Incorrect. This is a small excresence on a valve leaflet. It is uncommon.
(F) Incorrect. Kaposi sarcoma is seen in visceral locations in its epidemic form, now commonly associated with AIDS. The lesions are typically multiple and small. Involvement of the heart is rare.
(G) Incorrect. Rhabdomyomas are uncommon. Some are seen in assocciation with tuberous sclerosis. They are typically not hemorrhagic or necrotic.
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Question 2
A 45-year-old man was rushed to the hospital following the sudden onset of an episode of crushing substernal chest pain. He receives advanced life support measures. His course was marked by intractable cardiogenic shock and he died 4 days later. At autopsy, a large transmural anterolateral area of coagulative necrosis was found in the anterolateral wall of the left ventricle. Which of the following microscopic findings is most likely to be present?
A Fibroblasts and collagen
B Granulation tissue
C Necrotic muscle and neutrophils
D Granulomatous inflammation
E Diffuse chronic inflammation
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(C) CORRECT. After about 4 days following infarction, the muscle will still be necrotic and many neutrophils will persist, while macrophage infiltration will be beginning.
(A) Incorrect. Collagenization becomes more prominent following the first week after a myocardial infarction as healing continues. After a couple of weeks, the infarct consists mainly of collagen.
(B) Incorrect. Granulation tissue is most prominent after about a week after infarction and then collagenization becomes more prominent.
(D) Incorrect. Granulomatous inflammation is not typical for infarction.
(E) Incorrect. Chronic inflammation is more typical for viral myocarditis, not infarction.
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Question 3
A 45-year-old woman has had worsening shortness of breath for 3 years. She now has to sleep sitting up on two pillows. She has had difficulty swallowing for the past year. She has no history of chest pain. A month ago, she had a "stroke" with resultant inability to move her left leg and difficulty moving her left arm. She is afebrile. A chest radiograph reveals a near-normal left ventricular size with a prominent left atrial border. Which of the following conditions is most likely to account for these findings?
A Essential hypertension
B Cardiomyopathy
C Mitral valve stenosis
D Aortic coarctation
E Left renal artery stenosis
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(C) CORRECT. Mitral valve stenosis leads to left atrial enlargement, but the left ventricle is usually small. THere is typically a 'fishmouth' shaped mitral valve that has stenosis as well as insufficiency, since it does not close completely. Most mitral valvular disease in adults results from rheumatic valvulitis. The episode(s) of rheumatic fever occurred years before.
(A) Incorrect. This is probably the most common cause for left ventricular hypertrophy. The left atrium is not typically enlarged.
(B) Incorrect. Cardiomyopathies generally involve all heart chambers, including left ventricular hypertrophy with dilation, as well as right ventricular hypertrophy and dilation.
(D) Incorrect. The increased pressure load from the coarctation would lead to left ventricular hypertrophy.
(E) Incorrect. This would lead to hypertension and left ventricular hypertrophy.
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Question 4
A 16-year-old healthy adolescent is involved in a schoolyard gang fight and stabbed in the chest with a knife in the left midclavicular line. He is taken to the emergency department and on arrival his blood pressure is barely obtainable. His lungs are clear to auscultation. His heart sounds are barely audible. Which of the following is the most likely acute condition that may preclude his survival?
A Myocardial contusion
B Aortic laceration
C Pericardial tamponade
D Endocarditis
E Acute infarction
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(C) CORRECT. A stab wound into heart can lead to hemopericardium with tamponade.
(A) Incorrect. A contusion would not be a major consequence of injury from a sharp object.
(B) Incorrect. Aortic laceration is possible, but the heart (in a more anterior location and of a larger size) is the more likely target.
(D) Incorrect. It is possible that the stab wound could introduce infectious agents into heart, but this is not the major acute problem.
(E) Incorrect. Infarctions are a function of coronary artery disease. It is unlikely that a major coronary artery would be directly injured.
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Question 5
A 19-year-old woman has had increasing malaise for the past 5 months. On physical examination she has a cardiac murmur characterized by a mid systolic click. An echocardiogram demonstrates mitral insufficiency with upward displacement of one leaflet. There is aortic root dilation to 4 cm. She has a dislocated right ocular crystalline lens. A year later she dies suddenly and unexpectedly. The medical examiner finds a prolapsed mitral valve with elongation, thinning, and rupture of chordae tendineae. A mutation involving which of the following genes is most likely to be present in this patient?
A Beta-myosin
B CFTR
C FGFR
D Fibrillin
E Spectrin
F Dystrophin
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(D) CORRECT. Marfan syndrome is a connective tissue disorder that is associated with floppy mitral valve and also with cystic medial necrosis that predisposes to aortic dissection.
(A) Incorrect. Abnormalities of the beta-myosin gene may be associated with some forms of dilated cardiomyopathy.
(B) Incorrect. The CFTR gene is associated with cystic fibrosis. The obstructive lung disease from widespread bronchiectasis that results from cystic fibrosis involving the lung can lead to pulmonary hypertension with cor pulmonale.
(C) Incorrect. The fibroblast growth factor receptor gene mutations can be associated with skeletal dysplasias.
(E) Incorrect. The spectrin gene mutation can be associated with red cell membrane abnormalities associated with hereditary spherocytosis. Anemias in adults with this condition are not typically severe, though anemias in general can increase cardiac stress.
(F) Incorrect. The dystrophin gene is mutated with Duchenne muscular dystrophy, affecting striated muscle, which can lead to cardiac failure as the disease progresses.
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