Pediatric Examination and Board Review Read Online Free PDF Page A

defect has been identified in 50% of patients with clinical long QT syndrome. A less common mode of inheritance is autosomal recessive (Jervell and Lange-Nielsen syndrome). In these patients, there is often associated conductive hearing loss and a higher risk for ventricular arrhythmias and sudden death. Finally, some cases of congenital long QT syndrome occur because of spontaneous mutations. The risk for sudden death in patients with long QT syndrome who present with symptoms of dizziness or syncope is approximately 20% in 1 year, if untreated. The use of beta-blockers decreases the risk of sudden death to < 5%. Therefore, beta-blockers have become the mainstay of therapy as well as avoidance of strenuous activities, especially swimming. Pacemaker implantation is occasionally required for patients with either baseline bradycardia or those who develop bradycardia following treatment with betablockers. Implantable cardioverter defibrillators are now used more frequently in patients who continue to become symptomatic despite medical therapy with a beta-blocker or for those in whom there is a strong family history of sudden death.
    21. (B) Acquired long QT syndrome can occur with head trauma, myocardial infarction, cardiomyopathy, or as a result of drugs or medications. This list of drugs/medications associated with the acquired prolonged QT syndrome is extensive and updated regularly. Some of the more common medications on this list include amitriptyline or other tricyclic antidepressants, erythromycin, and cisapride.
    S UGGESTED R EADING
     
    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, PA: Hanley and Belfus; 2006.
    Park M, ed. Pediatric Cardiology for Practitioners. 5th ed. St. Louis, MO: Mosby; 2007.

CASE 3: A 7-YEAR-OLD WITH A HEART MURMUR
     
    A 7-year-old boy with no significant past medical history is noted to have a heart murmur heard for the first time during a routine physical evaluation by his lifelong pediatrician. The physical examination is significant for a grade 2/6 vibratory systolic murmur heard best at the lower left sternal border with no radiation. The remainder of the physical examination is normal.
    SELECT THE ONE BEST ANSWER
     
    1. What is the most likely diagnosis of this heart murmur?
(A) Still murmur
(B) ventricular septal defect
(C) atrial septal defect
(D) peripheral pulmonary stenosis
(E) venous hum
    2. What supporting evidence would help to confirm the diagnosis of an innocent Still murmur?
(A) a fixed, split second heart sound
(B) the murmur is louder in the supine position compared to the sitting or standing position
(C) a diastolic rumble
(D) the murmur is associated with a precordial thrill (grade IV)
(E) radiation to the back and axilla
    3. Which test would not be indicated for this patient at this time?
(A) ECG
(B) echocardiogram
(C) chest radiograph
(D) cardiac catheterization
(E) four extremity blood pressure determination
    4. What would be the appropriate advice to give the family regarding a child with this murmur?
(A) endocarditis prophylaxis is needed
(B) rigorous sports should be avoided
(C) sports participation is allowable
(D) annual echocardiograms are required
(E) other family members should be screened for heart disease
    5. A 6-week-old infant presents with a heart murmur and a history of poor feeding, diaphoresis, and tachypnea. On examination, he is playful but tachypneic with a grade 2/6 systolic regurgitant murmur heard best in the mid left sternal border, with hepatomegaly, rales, intermittent wheezes, cool extremities with normal distal pulses, and an active precordium. What is the likely diagnosis of this