Pediatric Examination and Board Review (10 page)

Allen HD, Driscoll DJ, Shaddy RE, Feltes TF, eds.
Moss and
Adams Heart Disease in Infants, Children and Adolescents.
7th ed. Philadelphia, PA: Williams and Wilkins; 2007.

Braunwald E, Zipes DP, Libbey P, eds.
Braunwald: Heart Disease: A Textbook of Cardiovascular Medicine.
7th ed. Philadelphia, PA: WB Saunders; 2004.

Keane JF, Fyler DC, Lock JE, eds.
Nadas’ Pediatric Cardiology.
2nd ed. Philadelphia: Hanley and Belfus; 2006.

Park M, ed.
Pediatric Cardiology for Practitioners.
5th ed. St. Louis, MO: Mosby; 2007.

CASE 4: A 5-YEAR-OLD WITH A HEART MURMUR AND FEVER

A 5-year-old child presents to the clinic with a history of fever, rash, a swollen knee and ankle, shortness of breath, and fatigue. His past medical history is significant for the fact that he had a streptococcal throat infection 3 weeks prior to this visit but did not take the amoxicillin that was prescribed. On physical examination, he has a temperature of 38.9°C. He has a grade 2/6 systolic regurgitant murmur heard best at the apex and an S3 gallop. He has hepatomegaly and good peripheral pulses.

SELECT THE ONE BEST ANSWER

1.
What is the most likely diagnosis in this child?

(A) acute rheumatic fever

(B) infective endocarditis

(C) Kawasaki disease

(D) sickle cell disease

(E) sepsis

2.
What is the most common cause of this disease?

(A) group A beta-hemolytic streptococcal pharyngitis

(B) group A beta-hemolytic streptococcal impetigo

(C)
Staphylococcus aureus
skin infection

(D) enterococcus infection

(E) influenza A infection

3.
What is the incidence of acute rheumatic fever following untreated streptococcal pharyngitis?

(A) 0.001%

(B) 0.3-3%

(C) 13-15%

(D) 25-33%

(E) 35-50%

4.
Which heart valve(s) is/are the most commonly affected with acute rheumatic fever?

(A) mitral valve

(B) aortic valve

(C) tricuspid valve

(D) pulmonary valve

(E) B and D

5.
Which of the following is not a major criterion for the diagnosis of acute rheumatic fever?

(A) erythema marginatum

(B) carditis

(C) chorea

(D) arthralgias

(E) arthritis

6.
Which statement is true regarding antibiotic therapy for acute rheumatic fever?

(A) eradication of streptococci from the pharynx is the goal

(B) penicillin prophylaxis for 1 year is required but then can be stopped earlier if the patient is well

(C) penicillin prophylaxis can be given either twice daily by mouth or once monthly by intramuscular (IM) injection

(D) oral sulfadiazine or tetracycline can be substituted for penicillin in patients who are penicillin allergic

(E) oral cephalosporins can be substituted for penicillin in patients who are penicillin allergic

7.
The heart murmur in this patient is most likely a result of which of the following?

(A) mitral valve regurgitation

(B) mitral valve stenosis

(C) tricuspid valve regurgitation

(D) pulmonary valve regurgitation

(E) aortic valve stenosis

8.
A 2-year-old child presents with a 10-day history of fever, a heart murmur, bilateral nonexudative conjunctivitis, swollen and erythematous lips and strawberry tongue with erythematous and edematous hands and feet, and a polymorphous rash on the face, trunks, and extremities. The most likely diagnosis in this patient is

(A) Kawasaki disease

(B) measles

(C) viral upper respiratory tract infection

(D) group A beta-hemolytic streptococcal pharyngitis

(E) Hodgkin lymphoma

9.
What acute finding would not be expected to be associated with this 2-year-old’s diagnosis?

(A) sterile pyuria

(B) hydrops of the gallbladder

(C) cervical adenopathy with at least one node longer than 1.5 cm

(D) thrombocytosis

(E) A and B

10.
Which of the following statements is true regarding coronary artery involvement with this 2-year-old’s disease?

(A) there is a 50% incidence of coronary artery aneurysms if untreated

(B) the peak incidence for coronary artery aneurysms is 6-12 months following the onset of fever

(C) patients with giant coronary artery aneurysms (>8 mm in diameter) are at highest risk for late stenosis and myocardial infarction

(D) coronary artery rupture is the most common cause of mortality within the first 7 days of the onset of fever

(E) coronary artery aneurysms are not at risk for development of thrombus

11.
The 2 drugs most commonly used for the acute management of this disease are

(A) aspirin and intravenous immunoglobulin (IVIG)

(B) penicillin and IVIG

(C) steroids and aspirin

(D) steroids and penicillin

(E) penicillin and aspirin

12.
A 5-year-old boy presents with a fever of 10 days, weight loss, night sweats, a new heart murmur, splenomegaly, joint pains, and a history of having had his teeth cleaned by the dentist 1 month prior to this visit. On examination, he was found to have a grade 2/4 diastolic murmur heard best at the midleft sternal border radiating to the apex. There is an S3 gallop rhythm. What is the most likely diagnosis for this patient?

(A) infective endocarditis

(B) juvenile rheumatoid arthritis

(C) Kawasaki disease

(D) acute rheumatic fever

(E) mononucleosis

13.
Which of the following laboratory evidence most likely supports the diagnosis of infective endocarditis?

(A) two positive blood cultures with the same organism and no other source other than the heart

(B) increased white blood cell count

(C) increased C-reactive protein (CRP)

(D) throat culture positive for group A betahemolytic streptococcus

(E) increased erythrocyte sedimentation rate (ESR)

14.
Which bacterial species would be the most common cause of infective endocarditis in this 5-year-old child?

(A) alpha-hemolytic streptococcus

(B)
Staphylococcus aureus

(C)
Staphylococcus epidermidis

(D)
Enterococcus faecalis

(E)
Bacteroides fragilis
or other anaerobe

15.
What percent of cases of infective endocarditis have negative blood cultures?

(A) 10%

(B) 20%

(C) 30%

(D) 40%

(E) 50%

16.
Which of the following heart lesions would not be considered an increased risk for the development of infective endocarditis?

(A) mitral regurgitation

(B) aortic insufficiency

(C) aortic stenosis

(D) atrial septal defect

(E) ventricular septal defect

17.
What is the most common antibiotic regimen that should be started in cases of suspected infective endocarditis before knowing the results of the blood culture?

(A) vancomycin or oxacillin and gentamicin

(B) ampicillin and gentamicin

(C) ampicillin and ceftriaxone

(D) vancomycin alone

(E) none of the above

18.
Which of the following procedures does not require endocarditis prophylaxis in patients who are susceptible to endocarditis?

(A) tonsillectomy

(B) urinary tract surgery

(C) professional dental cleaning

(D) endotracheal intubation

(E) cardiac surgery

ANSWERS

1.
(A)
The most common cause of this constellation of symptoms is acute rheumatic fever, a multisystem inflammatory disease. The disease occurs among children 5 to 15 years of age with a peak incidence at 8 years and is rarely seen in children younger than 2 years of age.

2.
(A)
Acute rheumatic fever is triggered by group A beta-hemolytic streptococcal infection of the upper respiratory tract. Acute rheumatic fever does not occur following streptococcal skin infections, staphylococcal infections, or enterococcal infections. The pathogenesis of rheumatic fever is thought to be secondary to an immune response to antigens in the M protein of the capsule of the group A beta-hemolytic streptococcus, which occurs in susceptible hosts and cross-reacts with similar epitopes in human joint tissue, heart, and brain tissue. Pathologic findings include inflammatory lesions that include perivascular granulomas consisting of infiltrates of cells and fibrin that are also known as Aschoff bodies.

3.
(B)
The incidence of acute rheumatic fever is approximately 0.3-3% in untreated patients with
Streptococcus pyogenes
pharyngitis. The onset of disease occurs 1-5 weeks later with a mean of 18 days following the onset of pharyngitis. The typical course includes pharyngitis with improvement of symptoms. Two weeks later the patient begins to develop a low-grade fever and the inflammatory response of rheumatic fever.