30 - CVS pathology mcqs - 11 to 15

Question 11
A 27-year-old G2 P1 woman has a screening ultrasound performed at 18 weeks gestation. The fetus is appropriate in size for 18 weeks. The fetal kidneys, liver, head, and extremities appear normal. However, the fetus has a heart with a membranous ventricular septal defect, overriding aorta, and marked pulmonic atresia. If the baby were to be liveborn, which of the following characteristics on physical examination would most likely result from these cardiac defects?
A Systemic hypertension
B Weak lower extremity pulses
C Clubbing of digits
D Telangiectasias
E Cyanosis
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(E) CORRECT. The features are those of tetralogy of Fallot, which producces a right-to left shunt with cyanosis from mixing of right heart blood with left heart blood.
(A) Incorrect. The cardiac output tends to be reduced with tetralogy of Fallot. Systemic hypertension is not typically a feature of most congenital heart diseases.
(B) Incorrect. Weaker pulses in the lower extremities, compared to upper extremities, suggest coarctation of the aorta, not tetralogy of Fallot.
(C) Incorrect. Finger clubbing is more typically seen with chronic pulmonary diseases.
(D) Incorrect. Telangiectasias are small vascular prominences that are not generally associated with congenital heart diseases.
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Question 12
A 50-year-old man has the sudden onset of substernal chest pain one afternoon. The pain persists for the next three hours. He then becomes short of breath and diaphoretic. He goes to the emergency department that evening. On physical examination his vital signs include T 37 C, P 95/minute, RR 25/minute, and BP 130/90 mm Hg. A chest radiograph shows a slightly enlarged heart and mild pulmonary edema. An EKG shows ST segment elevation in anterior leads V1 - 6. Which of the following serum laboratory test findings is most likely to be present in this man?
A Urea nitrogen of 110 mg/dL
B Sodium of 115 mmol/L
C ALT of 876 U/L
D Troponin I of 32 ng/mL
E HDL cholesterol of 55 mg/dL
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(D) CORRECT. The findings suggest an early ischemic event as part of a developing myocardial infarction. The troponin I can be elevated within a few hours, similar to the CK-MB.
(A) Incorrect. If he develops cardiac failure as a consequence of his ischemic event, then he may in time develop pre-renal azotemia from diminished cardiac output.
(B) Incorrect. Hyponatremia is not typically a feature of ischemic heart disease.
(C) Incorrect. Alanine aminotransferase is an enzyme whose elevation is more specific for hepatocyte injury.
(E) Incorrect. HDL cholesterol is the 'good' cholesterol that is more protective against ischemic heart disease.
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Question 13
A 44-year-old woman dies as a consequence of a "stroke". At autopsy, she is found to have a large right basal ganglia hemorrhage. She has an enlarged 550 gm heart with predominantly left ventricular hypertrophy. Her kidneys are small, about 80 gm each, with cortical scarring, and microscopically they demonstrate small renal arterioles that have luminal narrowing from concentric intimal thickening. Which of the following is the most likely diagnosis?
A Dominant polycystic kidney disease
B Arterial changes with diabetes mellitus
C Vascular disease with hyperlipidemia
D Malignant hypertension
E Monckeberg's sclerosis
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(D) CORRECT. The small arteries of the kidney are affected by hyperplastic arteriolosclerosis. Malignant hypertension is often preceded by chronic hypertension that leads to left ventricular hypertrophy. Hypertension is a risk for CNS hemorrhage.
(A) Incorrect. Dominant polycystic kidney disease is associated with intracranial aneurysms called 'berry aneurysms' which form in adult life in a location of weakness of the arterial wall.
(B) Incorrect. Diabetes mellitus is associated with accelerated atheroclerosis that involves the larger arteries, though hyaline arteriolosclerosis can occur in the kidneys.
(C) Incorrect. Hyperlipidemia is associated with atherosclerosis, not hyperplastic arteriolosclerosis.
(E) Incorrect. This is medial calcific sclerosis and is seen in older persons in small to medium-sized muscular arteries. It produces no serious consequences.
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Question 14
A 24-year-old woman with rheumatic heart disease becomes febrile. On physical examination she has a systolic murmur. An echocardiogram shows vegetations of the aortic valve cusps. A blood culture is positive for Staphylococcus epidermidis. She receives a porcine bioprosthesis because of her desire to have children and not to take anticoagulant medication. After ten years, she must have this prosthetic valve replaced. Which of the following pathologic findings in the bioprosthesis has most likely led to the need for replacement?
A Dehiscence
B Endocarditis
C Strut failure
D Calcification
E Thrombosis
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(D) CORRECT. The bioprosthesis has the advantage of not requiring anticoagulation, but it does not wear well with time, and typically must be replaced within 5 to 10 years when its leaflets undergo progressive calcification leading to stenosis.
(A) Incorrect. Dehisence, when the suture margin comes loose, is a rare complication that manifests soon after the surgery.
(B) Incorrect. Any abnormal endocardial surface is subject to a risk for infection and development of infective endocarditis, but this is not the reason to replace the valve after 5 to 10 years.
(C) Incorrect. Bioprostheses are not subject to component failure. The mechanical prosthesis now used are also quite reliable. A certain model of valve was 'recalled' some years ago because of the tendency of one component to break, and this type of valve is no longer used.
(E) Incorrect. Patients with mechanical prostheses are given anticoagulant therapy, but persons with bioprostheses do not need this medication.
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Question 15
A 25-year-old previously healthy woman dies suddenly and unexpectedly. She had complained only of a slight headache for 3 days before her demise. At autopsy, the medical examiner finds an enlarged, dilated 410 gm heart with only minimal coronary atherosclerosis and normal cardiac valves. Microscopically, the myocardium on both the right and the left ventricles demonstrates infiltration by small lymphocytes, with focal myocyte necrosis. Which of the following infectious agents is most likely to have caused these findings?
A Coxsackie B virus
B Candida albicans
C Aspergillus fumigatus
D Streptococcus, viridans group
E Staphylococcus aureus
F Cytomegalovirus
G Streptococcus, group A
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(A) CORRECT. The most common cause for a primary myocarditis is a virus (such as Coxsackie virus). Viral myocarditis can be a cause for sudden death in a young person.
(B) Incorrect. Candida myocarditis is rare. It may occur in some immunocompromised patients.
(C) Incorrect. Fungal infections of the heart are rare. They are usually seen in immunocompromised patients.
(D) Incorrect. S. viridans is a cause for bacterial endocarditis. A myocarditis could be produced from septic emboli from vegetations, but this is not common.
(E) Incorrect. S. aureus is a cause for bacterial endocarditis. A myocarditis could be produced from septic emboli from vegetations, but this is not common.
(F) Incorrect. Cytomegalovirus is a rare cause for myocarditis, seen in immunocompromised persons.
(G) Incorrect. Group A streptococcal infections are a cause for rheumatic fever, which may produce a myocarditis with granulomatous inflammation characterized by Aschoff nodules.
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