2014 Peds Q&as Answers Book Cardio

MedStudy

®

2014 2 0 0 9

Pediatrics

Board-Style

Questions

&

Answers

ANSWERS

Edited by Robert A. Hannaman, MD

MedStudy TABLE OF CONTENTS ADOLESCENCE.............................................................. ALLERGY / IMMUNOLOGY / RHEUMATOLOGY .... CARDIOLOGY ................................................................ DERMATOLOGY............................................................ EMERGENCY MEDICINE ............................................. ENDOCRINOLOGY ........................................................ ENT / OPHTHALMOLOGY / ORTHOPEDICS ............. GASTROENTEROLOGY ................................................ GENETICS / METABOLIC DISEASES ......................... GROWTH and DEVELOPMENT .................................... HEALTH SUPERVISION................................................ HEMATOLOGY / ONCOLOGY ..................................... INFECTIOUS DISEASES................................................ NEPHROLOGY ............................................................... NERVOUS SYSTEM / NEUROLOGY ........................... NEWBORN / PRENATAL CARE ................................... NUTRITION / TEETH ..................................................... RESPIRATORY ...............................................................

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Important: These Q&A books are meant to be used as an adjunct to the MedStudy Pediatrics Review Core Curriculum. The Pediatric Boards cover a vast realm of diagnostic and treatment knowledge. Board-simulation exercises such as these self-testing Q&As are valuable tools, but these alone are not adequate preparation for a Board exam. Be sure you use a comprehensive Pediatrics review resource in addition to these Q&As for adequate exam preparation. Content: The primary purpose of this activity is educational. Medicine and accepted standards of care are constantly changing. We at MedStudy do our best to review and include in this activity accurate discussions of the standards of care, methods of diagnosis, and selection of treatments. However, the author, editors, advisors, and publisher—and all other parties involved with the preparation of this work—disclaim any guarantee that the information contained in this activity and its associated materials is in every respect accurate or complete. MedStudy further disclaims any and all liability for damages and claims that may result from the use of information or viewpoints presented. We recommend you confirm the information contained in this activity and in any other educational material with current sources of medical knowledge whenever considering actual clinical presentations or treating patients. A note on editorial style: MedStudy follows a standardized approach to the naming of diseases, using the non-possessive form when the proper name of a disease is followed by a common noun. So you will see phrasing such as “This patient would warrant workup for Crohn disease” (as opposed to “Crohn’s disease”). Possessive form will be used, however, when an entity is referred to solely by its proper name without a following common noun. An example of this would be “The symptoms are classic for Crohn’s.” Styles used in today’s literature can be highly arbitrary, some using possessive and some not, but we believe consistency is important. It has become nearly obsolete to use the possessive form in terminology such as Lou Gehrig’s disease, Klinefelter’s syndrome, and others. The AMA Manual of Style, JAMA, Scientific Style and Format, and Pediatrics magazine are among the publications that are now promoting and using the non-possessive form. We concur with this preference. © 2014 by MedStudy Corporation. All rights reserved by MedStudy Corporation WARNING: THE UNAUTHORIZED REPRODUCTION OR DISTRIBUTION OF THIS COPYRIGHTED WORK IS ILLEGAL. CRIMINAL COPYRIGHT INFRINGEMENT, INCLUDING INFRINGEMENT WITHOUT MONETARY GAIN, IS INVESTIGATED BY THE FBI AND IS PUNISHABLE BY UP TO 5 YEARS IN FEDERAL PRISON AND A FINE OF $250,000. ANY PERSON MAKING, SELLING, OR PURCHASING UNAUTHORIZED COPIES OF THIS MATERIAL WILL BE SUBJECT TO LEGAL ACTION AND SEVERE PENALTIES UNDER U.S. COPYRIGHT LAW, AND MAY FACE CRIMINAL CHARGES. Notifications of copyright infringement should be sent in confidence to MedStudy Corporation, 1455 Quail Lake Loop, Colorado Springs, Colorado 80906 Or e-mail to: [email protected] MEDSTUDY 1455 Quail Lake Loop Colorado Springs, CO 80906 (800) 841-0547

2014 Pediatrics Board-Style Answers

CARDIOLOGY 72. Answer: B Answer: Tilt table test. The patient was prescribed fludrocortisone, a commonly recommended treatment in individuals with neurocardiogenic syndrome (vasovagal syncope). This disorder is thought to represent a neurally-mediated reflex response, which leads to vasodilatation and/or bradycardia, followed by a syncopal episode associated with systemic hypotension and cerebral hypoperfusion. The syncopal episode is brief—not associated with tonic-clonic seizure-like activity—and may follow emotional stress, a painful or noxious stimuli, prolonged standing, or exposure to high ambient temperatures. Patients frequently recall associated nausea, dizziness, and profuse sweating. They quickly improve when placed in the supine position with the legs elevated, restoring adequate cerebral blood flow. The tilt table test, in conjunction with isoproterenol infusion, is used to confirm the diagnosis of neurocardiogenic syncope. During testing, the patient is quickly moved from the supine to a standing position while observing for any change in level of consciousness and monitoring blood pressure and heart rate. A positive test is associated with bradycardia—often < 35–40 beats/minute, hypotension, and/or altered consciousness. Many patients are able to prevent recurrent episodes by maintaining adequate fluid and salt intake. The synthetic mineralocorticoid fludrocortisone (0.1–0.5 mg/day) is sometimes required to reduce the frequency of recurrent episodes. The drug acts to increase blood volume and enhance sensitivity of blood vessels to circulating catecholamines. Board Testing Point: Recognize neurocardiogenic syndrome, recall that this disorder is often treated with fludrocortisone, and then recall the recommended evaluation of patients suspected of having this disorder. __________________________________________________________________________________________

73. Answer: A Answer: A systolic ejection murmur, best heard at the mid-to-upper left sternal border associated with a loud first and widely fixed, split-second heart sound. The patient has evidence of an atrial septal defect (ASD) on echocardiogram. The systolic ejection murmur associated with this defect is the result of increased blood flow across the right ventricular outflow tract into the pulmonary artery and is not due to low pressure flow through the defect itself. The murmur is best heard at the mid-to-upper left sternal border and is characteristically associated with a loud first heart sound and a fixed, split-second heart sound that does not vary with respiration. Normally the duration of right ventricular ejection varies with respiration, with right ventricular volume increasing with inspiration, therefore delaying closure of the pulmonary valve. In the presence of an ASD, right ventricular diastolic volume is constantly increased and the ejection time prolonged throughout all phases of respiration. A right ventricular systolic lift at the left sternal border, which is caused by increased right ventricular systolic volume, may also be present. Increased volume load may also be evident on ECG, while chest x-ray may show enlargement of both the right atrium and right ventricle. Most patients remain asymptomatic until the 3rd or 4th decade of life, when they may develop decreased exercise tolerance, signs of heart failure, valvular insufficiency, and arrhythmias. Board Testing Point: Recognize findings on echocardiogram consistent with an atrial septal defect, and then recall expected findings during cardiac auscultation in patients with this defect. __________________________________________________________________________________________

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Cardiology Answers

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MedStudy

74. Answer: A Answer: Intermittent episodes of supraventricular tachycardia. The patient has a shortened (< 120 milliseconds) PR interval and a widened QRS complex. These findings, in addition to a slow upstroke of the QRS complex (the so-called delta wave) are consistent with Wolff-Parkinson-White (WPW) syndrome, an atrioventricular reentrant tachycardia in which the heart rate often exceeds 200 beats/minute. Episodes of tachycardia are characterized by abrupt onset and termination and due to aberrant conduction of ventricular activation through an anomalous accessory pathway, bypassing the AV node and the normal ventricular conduction pathway. The average duration is 10–15 minutes, although these episodes may be as brief as only 2–3 minutes or as long as several hours. Tachycardia and hypotension are associated with complaints of palpitations, chest pain, fatigue, and lightheadedness. Infants commonly present with heart failure and a history of cough, cyanosis, poor feeding, irritability, and restlessness. Atrial fibrillation may develop in some patients, often presenting as syncope in older children and adolescents. Vagal maneuvers (submersion of the face in iced saline, breath holding, straining with Valsalva) will sometimes abort the tachycardia. If unsuccessful, or in acutely ill patients, adenosine should be administered while closely monitoring the cardiac status of the patient. With frequent episodes of tachycardia, chronic therapy with a beta-blocker is indicated. Board Testing Point: Recognize ECG findings consistent with WPW syndrome and then recall the characteristic clinical presentation in individuals with this disorder. __________________________________________________________________________________________

75. Answer: A Answer: Muffled heart sounds on auscultation. The patient has evidence of postpericardiotomy syndrome, characterized by the development of pericarditis and/or pericardial effusion days to several weeks after cardiac surgery. Thought to represent an inflammatory or immune mediated response, postpericardiotomy syndrome develops in up to 5%–6% of patients who have recently undergone an open cardiac procedure. Associated symptoms include chest pain, cough, shortness of breath, decreased exercise tolerance, malaise, anorexia, increased temperature, and headache. Physical findings may include tachycardia, hypotension, muffled heart sounds, and/or a pericardial friction rub. The presence of pulsus paradoxus (an inspiratory decrease in systolic blood pressure of > 10 mmHg) indicates the presence of pericardial tamponade. A plain radiograph of the chest in patients with pericardial effusion reveals massive enlargement of a globular-shaped heart. Low voltage is typically noted on ECG, sometimes associated with beat-to-beat variability in voltage as the heart moves about within the pericardial fluid. Corticosteroids and nonsteroidal antiinflammatory medications hasten recovery. Some patients may require pericardiocentesis and intravascular fluid to reverse reduced diastolic compliance and systemic venous return | due to accumulated pericardial fluid. Board Testing Point: Recognize clinical findings consistent with postpericardiotomy syndrome, and then recall associated findings in patients with this disorder. __________________________________________________________________________________________

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2014 Pediatrics Board-Style Answers

76. Answer: A Answer: Sharply demarcated annular scaling plaques on the cheeks and periocular areas. The patient has ECG findings consistent with complete heart block. Neonatal lupus erythematosus is the most frequent cause of congenital heart block, which is the result of in utero inflammation and fibrosis of the atrioventricular (AV) node following transfer of maternal antibodies (anti-SSA, anti-Ro). Heart block due to neonatal lupus erythematosus may also be associated with cardiomyopathy, congestive heart failure and/or congenital heart defects. Mothers are at risk of not only systemic lupus erythematosus but also of rheumatoid arthritis, Sjögren syndrome, and other connective tissue disorders. Lesions of neonatal lupus are characterized by erythematous, well-circumscribed, scaly, annular plaques that leave behind a central ecchymotic atrophic area as they expand. Lesions are most often located over the scalp and in the periocular and other sun-exposed areas. Although present at birth in some people, lesions may not be noted until the infant has been exposed to the sun. Associated systemic complications include hepatomegaly associated with elevated serum transaminases, splenomegaly, lymphadenopathy, leukopenia, thrombocytopenia, and anemia. Cutaneous, gastrointestinal, and hematologic manifestations resolve with disappearance of maternal antibodies. Residual skin changes are common. However, cardiac complications are permanent with the majority of affected infants requiring a pacemaker. “Reticulate bluish mottling of the lower extremities” describes cutis marmorata, a normal finding in young infants due to a physiologic response to chilling with resultant dilation of capillaries and small venules. “Indurated, wellcircumscribed nodular erythematous plaques on the shoulders and back” describes subcutaneous fat necrosis thought to be related to perinatal trauma, but also more common following perinatal asphyxia and/or hypothermia, and, in other cases, hypercalcemia. “Blotchy erythematous macules and edematous, yellowish papules and pustules on the face, trunk, and extremities” describes erythema toxicum—an asymptomatic, benign, self-limited eruption in newborns. “Papules and papulopustules associated with fine, white scales and hyperpigmented macules in areas where previous lesions have ruptured; located primarily on the inferior chin, neck, and forehead” describes transient neonatal pustular melanosis, a benign, self-limited eruption more common among AfricanAmerican infants. Board Testing Point: Recognize ECG evidence of complete heart block, recall that this finding is often associated with neonatal lupus erythematosus, and recall the clinical appearance of the rash associated with this disorder. __________________________________________________________________________________________

77. Answer: C Answer: Maneuvers that increase left ventricular volume enhance ausculatory findings. The patient in the vignette has ausculatory findings consistent with mitral valve prolapse (MVP), the most common valvular heart abnormality. MVP is often asymptomatic or may be associated with nonspecific signs and symptoms including palpitations with or without chest pain, dizziness, and panic attacks. Maneuvers that increase left ventricular volume enhance the typical auscultatory findings of a mid-systolic click followed by a soft mid- to late systolic murmur best heard at the apex of the left ventricle over the mitral area. The mid-systolic click results from the sudden snapping of the chordae tendineae as one or more mitral leaflets prolapse into the left atrium. Sitting or standing moves the click closer to the first heart sound as a result of decreased ventricular volume. The mid- to late systolic murmur represents turbulent mitral regurgitation. Associated conditions include connective tissue disorders (Marfan syndrome, Ehlers-Danlos syndrome), osteogenesis imperfecta, adult polycystic kidney disease, dilated cardiomyopathy, hypertrophic cardiomyopathy, and, because of decreased blood volume, anorexia nervosa. The diagnosis is best confirmed by echocardiography. Board Testing Point: Recognize auscultatory findings consistent with mitral valve prolapse, and then recall associated features in individuals with this disorder. © 2014 MedStudy

Cardiology Answers

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MedStudy

78. Answer: B Answer: Kawasaki disease. Therapy with intravenous immune globulin (IVIG) and aspirin (80–100 mg/kg/day) is recommended in patients with Kawasaki disease to decrease the risk of development of coronary artery abnormalities. Patients with severe selective IgA deficiency, defined by a serum IgA concentration of < 7 mg/dL and normal serum levels of IgG and IgM, may have preformed IgG and/or IgE antibodies against IgA. As a result (although rare), anaphylaxis may follow administration of IVIG, presenting with diffuse flushing, urticaria, hypotension, tachycardia, chest pain (sometimes radiating to the back) or tightness, shortness of breath, nausea, and/or vomiting. IgA deficiency is not a contraindication to treatment with IVIG; rather, a product with low IgA content should be selected and administered cautiously with premedication with antihistamines and/or glucocorticoids. IVIG is also often recommended in patients with primary immunodeficiencies, human immunodeficiency virus infection, GuillainBarré syndrome, immune-mediated thrombocytopenia, and in the early treatment of toxic shock syndrome. Fever, headache, myalgia, chills, and nausea are relatively common adverse reactions following IVIG administration. Screening for IgA deficiency is not routinely recommended prior to treatment with IVIG. Board Testing Point: Recall that selective IgA deficiency is associated with an increased risk of adverse events following treatment with intravenous immune globulin products and recall specific diseases in which such treatment is routinely indicated. __________________________________________________________________________________________

79. Answer: A Answer: Erythematous, serpiginous macular lesions with pale centers on the trunk and extremities. The patient has clinical and ECG findings consistent with acute rheumatic fever. The major manifestations of rheumatic fever (Jones criteria) are carditis, polyarthritis, subcutaneous nodules, chorea, and erythema marginatum. Minor manifestations include arthralgia, fever, leukocytosis, elevated acute phase reactants (ESR, C-reactive protein), prolonged PR interval, and previous rheumatic fever or rheumatic heart disease. The presence of two major or of one major and two minor manifestations, in association with laboratory evidence of a preceding group A streptococcal infection, indicates a high probability of acute rheumatic fever. A preceding group A streptococcal infection is best evaluated by measurement of antistreptolysin O, anti-DNase B, and antihyaluronidase antibodies. Erythema marginatum is characterized by nonpruritic, erythematous serpiginous (polycyclic) macular lesions with red borders and pale centers. Lesions are most prominent on the trunk (especially the abdomen) and extremities and tend to predominate during episodes of increased temperature or following gentle warming of the skin. Lesions often fade within hours leaving behind a pale or pigmented center. “Diffusely distributed, round erythematous swollen plaques, target lesions, and marginated wheals with central vesicles” describes erythema multiforme. “Diffuse erythema with small punctate papules accentuated in the flexural areas” describes scarlet fever. “Erythematous macules and petechiae prominent around the ankles, wrists, palms, and soles” describes Rocky Mountain spotted fever. Finally, “deep-seated and more superficial vesicles with peripheral erythema on the palms and plantar surfaces” describes lesions typically caused by coxsackievirus. Board Testing Point: Recognize clinical and ECG findings consistent with acute rheumatic fever, and recall the typical appearance of the rash associated with this disorder. __________________________________________________________________________________________

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2014 Pediatrics Board-Style Answers

80. Answer: C Answer: Reye syndrome. During the acute phase of Kawasaki disease, children are treated with a single dose of intravenous immune globulin and high-dose (80–100 mg/day) aspirin for a period of several days to a week or more. Low-dose aspirin is then continued until laboratory markers of acute inflammation return to normal, and there are no coronary artery abnormalities detected by serial echocardiography. Salicylates are a major precipitating factor for Reye syndrome, a rapidly progressive encephalopathy associated with hepatic dysfunction in children recovering from viral infections, especially influenzae and varicella. In this disorder, vomiting and altered mental status quickly progress to seizures and coma associated with elevated serum transaminases, hyperammonemia, hypoglycemia, metabolic acidosis, and multisystem organ failure. Therefore patients receiving long-term salicylate therapy should be considered at high risk of complications of influenzae and varicella infection. Influenzae A and B cause the sudden onset of a progressively severe nonproductive cough, nasal discharge, nonpurulent conjunctivitis, and pharyngitis associated with malaise, myalgia, and headache. Distinct serotypes of influenzae A and B are responsible for annual infections in all age groups. Changes in circulating serotypes frequently occur. Minor changes within a serotype are termed antigenic drift while more significant changes are referred to as antigenic shift. Other patients at particular risk of complications associated with influenzae include those with diabetes mellitus, hemoglobinopathy, asthma and other chronic respiratory disorders, renal impairment, congenital heart disease, and an underlying immunocompromised state. Annual influenzae immunization is recommended for all children 6 months through 18 years of age; household contacts and out-of-home caregivers of children 0 through 59 months of age and adults 50 years of age and older; and household contacts and caregivers of people with medical conditions that place them at high risk of severe complications of influenzae. Board Testing Point: Recall that long-term salicylate therapy is recommended to decrease the risk of coronary artery aneurysm in children with Kawasaki disease and recognize that such patients are at increased risk of Reye syndrome following infection with an influenzae virus. __________________________________________________________________________________________

81. Answer: A Answer: Coronary artery dilation of ≥ 8 mm. Coronary artery aneurysm is the most serious complication of Kawasaki disease, placing patients at increased risk of ischemic heart disease secondary to coronary artery thrombosis and progressive stenosis within the aneurysm. Long-term prognosis depends upon the size and shape of the aneurysm. The best prognosis is associated with smaller aneurysm size; those with an internal diameter ≥ 8 mm are associated with the highest risk of morbidity and mortality. As many as 30–35% of such aneurysms become obstructed, leading to complications that may include myocardial infarction, arrhythmias, or sudden death. Late diagnosis and treatment ( ≥ 10 days of onset of symptoms) with intravenous immune globulin (2 g/kg over 8–10 hours) is the most important risk factor associated with development of coronary artery aneurysms. Additional risk factors include age younger than one year and older than 9 years, male sex, longer duration of fever, persistence of laboratory evidence of inflammation (anemia, elevation of ESR and CRP), and failure to respond to the initial dose of intravenous immune globulin.

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MedStudy Diagnostic criteria for typical Kawasaki disease include fever for five or more days and the presence of at least four of the following: bilateral nonexudative, nonulcerative bulbar conjunctival injection; oral mucous membrane changes (injected/fissured lips, injected pharynx, strawberry tongue); changes in the peripheral extremities (erythema of palms/soles, edema of hands or feet during the acute phase followed by periungual desquamation during the convalescent phase); polymorphous (scarlatiniform, morbilliform, maculopapular, multiforme-like) rash; cervical lymphadenopathy(at least one lymph node > 1.5 cm in diameter). In addition to treatment with intravenous immune globulin, it is recommended that patients receive 80–100 mg/kg of aspirin during the acute phase followed by low-dose aspirin until cardiovascular status returns to normal. Board Testing Point: Recall specific risk factors that increase the incidence of morbidity among patients with Kawasaki disease. __________________________________________________________________________________________

82. Answer: A Answer: A double aortic arch. The patient has clinical and radiographic findings consistent with a vascular ring, characterized by one of several congenital abnormalities that affect the aortic arch and its major branches. Specific radiographic findings associated with a double aortic arch include widening of the base of the heart and forward displacement of a narrowed trachea at C3–C4. Clinical signs and symptoms include stridor, chronic wheezing, respiratory distress, apnea, and swallowing dysfunction and vomiting. Extension of the neck may improve respiratory symptoms while flexion often exacerbates symptoms. Bilateral indentation of the esophagus is typically noted on barium swallow while pulsatile bilateral tracheal compression is seen on bronchoscopy. CT and MRI are diagnostic in differentiating the various types of vascular rings. Other types of vascular rings–all of which are associated with specific findings on chest x-ray, bronchoscopy, and barium swallow–include a right aortic arch, anomalous innominate artery, anomalous left carotid artery, aberrant right subclavian artery, and anomalous left pulmonary artery or pulmonary sling. Complete vascular rings encircle both the trachea and esophagus; incomplete rings affect only one of the two structures. Surgery is indicated both to relieve symptoms and lessen the risk of associated complications. Board Testing Point: Recognize a vascular ring, and then recognize that the specific radiographic findings described are most consistent with a double aortic arch. __________________________________________________________________________________________

83. Answer: B Answer: Hypercalcemia. Specific ECG changes may be the first indication of an underlying electrolyte or metabolic abnormality. Hypercalcemia (> 12 mg/dL) causes a shortening of the QT interval in addition to a decrease in the proximal portion of the P wave, resulting in an abrupt upstroke in the initial portion of the P wave. Hypercalcemia occurs when the entry of calcium into the circulation exceeds urinary excretion of calcium or exceeds calcium deposition in bone due to increased bone resorption, excessive gastrointestinal absorption, or decreased renal excretion. Increased bone resorption is common among children with cancer secondary to release of calcium from bony metastasis associated with solid tumors or from leukemic marrow infiltration. Hypercalcemia due to increased bone resorption is also associated with hyperparathyroidism and thyrotoxicosis. It also accompanies a variety of miscellaneous disorders including hypervitaminosis A, pheochromocytoma, adrenal insufficiency, and rhabdomyolysis. Toxic ingestion of lithium, thiazide diuretics, and theophylline are frequently complicated by severe hypercalcemia.

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2014 Pediatrics Board-Style Answers Hypokalemia is associated with a decrease in T-wave amplitude and a U wave (biphasic T wave). Hyperkalemia is associated with peaked T waves and a prolonged PR interval. Hypocalcemia is associated with a prolonged QT interval. Hypothermia is associated with prolongation of the RR, QT, PR, and QRS intervals. Board Testing Point: Recall associated changes on ECG in patients with electrolyte or temperature abnormalities. __________________________________________________________________________________________

84. Answer: C Answer: The PR interval. The electrographic cardiac cycle represents atrial systole, ventricular systole, and the resting stage between beats. The P wave correlates with atrial contraction while the PR interval represents the time it takes for the cardiac impulse to travel through the AV node. The QRS complex represents ventricular depolarization. The ST segment correlates with the initial phase of ventricular repolarization; the T wave represents ventricular repolarization. The QT segment, which includes the QRS complex and the T wave, represents complete ventricular systole. Normally, the P wave is positive leads I, II, and aVF; each P wave should be followed by a QRS complex. A normal PR interval is indicative of a normally functioning AV node. Outside of the newborn period, at which time the QRS deflection is negative in lead I and positive in lead aVF, the normal QRS is positive in lead 1 and negative in aVF. Ventricular condition delay widens the QRS complex; QRS amplitude is used to evaluate for ventricular hypertrophy. Elevation of the ST segment may be due to infarction, myocardial strain, or pericarditis; ST depression correlates with perfusion defects to the myocardium. The T wave is normally inverted in leads V1–V3 into adolescence. A peaked T wave is associated with hyperkalemia; the T wave is depressed and takes on a bifid configuration (U wave) in hypokalemia. The corrected QT (QTc) interval should be < 440 ms; prolongation of the QT interval is associated with malignant arrhythmias. Board Testing Point: Recall what each component of the electrographic heart cycle represents. __________________________________________________________________________________________

85. Answer: A Answer: Abnormal development of the pulmonary veins. The so-called “snowman sign” is a typical radiographic finding in patients with anomalous pulmonary venous return, characterized by abnormal development of the pulmonary veins, resulting in either partial or complete anomalous drainage into the venous circulation. A rounded, figure of eight-like cardiac contour and supracardiac shadow in the superior mediastinum (“the snowman”) is produced by dilated vertical anomalous veins, the left innominate vein, and the superior vena cava in association with a dilated left ventricle. Additional radiographic findings often include a fine, reticular pattern of pulmonary venous obstruction and pulmonary edema, which may mimic neonatal respiratory distress syndrome. Infants with severe obstruction to pulmonary venous return present during the neonatal period with cyanosis and marked respiratory distress; mild or moderate obstruction may present later in infancy with signs and symptoms of congestive heart failure. In those patients without pulmonary venous obstruction and total mixing of systemic venous and pulmonary venous blood and a left to right shunt, cyanosis is mild, and symptoms are generally far less severe. Anatomical findings of L-transposition of the great arteries are described as “discordant atrioventricular relationships.” “Downward displacement of an abnormal tricuspid valve into the right atrium” describes findings typical of Ebstein anomaly. “Anterior deviation of the infundibular septum” describes the anomaly associated with tetralogy of Fallot, and “a single arterial trunk arising from the heart” describes a truncus arteriosus.

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Cardiology Answers

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MedStudy Board Testing Point: Recall radiographic findings in patients with congenital heart disease, and then recall specific anatomical abnormalities associated with specific types of congenital heart disease. __________________________________________________________________________________________

86. Answer: D Answer: Amoxicillin 2 gm orally one hour before the procedure. Antimicrobial prophylaxis is recommended in patients with prosthetic heart valves, prosthetic material used for cardiac valve repair, unrepaired cyanotic congenital heart disease (including palliative shunts and conduits), congenital heart defects repaired with prosthetic material within the last 6 months, or partially repaired congenital heart disease with a residual defect(s) at or adjacent to the site of a prosthetic device. Antimicrobial prophylaxis is not recommended in patients with a bicuspid aortic valve, acquired aortic or mitral valve disease (including mitral valve prolapse with or without regurgitation), or hypertrophic cardiomyopathy. Dental, oral, and respiratory procedures that may result in transient bacteremia include those that involve manipulation of gingival tissue or the periapical region of the teeth, perforation of the oral mucosa, tonsillectomy, adenoidectomy, and bronchoscopy with biopsy. The recommended antibiotic regimen for dental, oral, and respiratory procedures is a single dose of amoxicillin 2 gm orally, 30–60 minutes prior to the procedure. Patients allergic to penicillin may be treated with cephalexin (2 gm), azithromycin (500 mg), or clindamycin (600 mg). Board Testing Point: Recall recommendations for antimicrobial prophylaxis for bacterial endocarditis prior to procedures, which may result in transient bacteremia. __________________________________________________________________________________________

87. Answer: B Answer: Indomethacin. Clinical findings described in the vignette are typical of a patent ductus arteriosus, characterized by left-to-right or bidirectional shunting and bounding peripheral pulses, a hyperdynamic precordium, wide pulse pressure, and a continuous “machinery-like” murmur. Respiratory manifestations include apnea, carbon dioxide retention, and an increasing oxygen requirement. In the fetus, pulmonary arterial blood is shunted through the ductus into the aorta. Functional closure, which normally occurs soon after birth, often does not take place in premature infants, causing shunting of aortic blood into the pulmonary artery and leading to left ventricular volume overload and pulmonary edema. A patent ductus is associated with more prolonged and severe respiratory distress syndrome, bronchopulmonary dysplasia, and increased mortality among very low-birth-weight infants. Fluid restriction and diuretics often improve associated symptoms. Indomethacin is the drug of choice for medical closure of a patent ductus; contraindications include thrombocytopenia, oliguria, necrotizing enterocolitis, renal failure, and intestinal perforation. Some infants will require surgical closure. Board Testing Point: Recognize findings consistent with a patent ductus arteriosus, and then recall treatment recommendations for this disorder. __________________________________________________________________________________________

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2014 Pediatrics Board-Style Answers

88. Answer: A Answer: Displacement of the tricuspid valves and a dilated right atrium. Ebstein anomaly, a defect characterized by downward displacement of an abnormal tricuspid valve into the right ventricle, is often associated with supraventricular dysrhythmias including Wolff-Parkinson-White syndrome. In Ebstein anomaly, the electrocardiogram demonstrates tall, peaked P waves in leads II and V1 (compatible with right atrial hypertrophy), right axis deviation (e.g., rS in leads I and aVL), and a right bundle-branch block pattern. Additional anomalies associated with this condition include division of the right ventricle into two sections; a thin-walled “atrialized” portion continuous with the right atrial cavity; and a smaller second portion of normal ventricular myocardium. Right atrial hypertrophy diminishes the size and functioning of the right ventricle; output from the right side of the heart is further compromised by tricuspid valve regurgitation and variable degrees of obstruction to right ventricular outflow. The severity of symptoms is quite variable, depending upon the extent of tricuspid valve displacement and obstruction of the right ventricular outflow tract. Symptoms may appear soon after birth or may be delayed until the teenage years. Symptomatic neonates will require surgery; in older children and adolescents, control of supraventricular dysrhythmias is of primary importance. Board Testing Point: Recognize clinical and electrocardiographic findings of Ebstein anomaly, and then recall additional manifestations of this disorder on echocardiography. __________________________________________________________________________________________

89. Answer: D Answer: Angiotensin-converting enzyme inhibitors. Major side effects of angiotensin-converting enzyme (ACE) inhibitors include cough, rash, loss of taste and hyperkalemia; rare adverse events include leukopenia, anemia, and angioedema. ACE inhibitors are contraindicated in pregnant adolescents and in children with hyperkalemia, impaired renal function, and/or bilateral renal artery stenosis. ACE inhibitors are the preferred treatment in hypertensive diabetics, hypertensive patients with microalbuminuria or proteinuria, and in obese patients. Hypertension guidelines include three categories: prehypertension, stage 1 hypertension, and stage 2 hypertension. Hypertension is defined as blood pressure ≥ 95th percentile for sex, age, and height on at least three occasions over a period of days–weeks. Prehypertension is defined ≥ 90th but < 95th percentile, or at least 120/80 mmHg but less than the 95th percentile. Stage 1 hypertension is defined as the 95th percentile to 5 mmHg > 99th percentile. Stage 2 hypertension is defined as more than 5 mmHg > 99th percentile. Electrolytes (hyperkalemia) and renal function studies should be obtained a week after initiating treatment, with every dose increase, and then every 6–12 months. ACE inhibitors may cause a dry, hacking, nonproductive cough within the first several months of treatment, which typically resolves within 1–4 weeks after discontinuation. Board Testing Point: Recall adverse effects of antihypertensive medications. __________________________________________________________________________________________

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MedStudy

90. Answer: A Answer: High pulmonary vascular resistance. The patient in the vignette has clinical and radiographic manifestations of Eisenmenger syndrome. It may develop in any patient with an untreated congenital cardiac defect associated with an intracardiac shunt. Shunting leads to pulmonary hypertension and reversal of flow across the defect from left-to-right to right-to-left secondary to elevated pulmonary artery pressures and pulmonary vascular disease in the small arterioles and muscular arteries. This physiologic abnormality most often occurs with a ventricular or atrial septal defect or patent ductus arteriosus. Symptoms do not usually occur until mid-to-late adolescence or the third decade of life. Patients typically complain of shortness of breath, decreased exercise tolerance, lethargy and fatigue; hemoptysis, syncopal episodes, and dysrhythmias are common. Cyanosis, clubbing, and signs of congestive heart failure may be noted on physical exam; precordial palpation reveals a right ventricular heave. On auscultation, the second heart sound is narrowly split with a loud pulmonic component; a holosystolic murmur of tricuspid regurgitation along the left sternal border and/or an early decrescendo diastolic murmur of pulmonary insufficiency may be noted. On chest x-ray, the heart is often enlarged with prominent pulmonary vessels in the hilar regions, which rapidly taper in the peripheral branches, causing under-vascularity in the peripheral areas. The ideal treatment is one of prevention by early recognition and surgical repair of the intracardiac communication or patent ductus. Medical treatment of Eisenmenger syndrome is primarily symptomatic. Board Testing Point: Recognize clinical and radiographic findings consistent with Eisenmenger syndrome, and then recall the associated pathophysiology of this disorder. __________________________________________________________________________________________

91. Answer: B Answer: Vitamin B1 (thiamine). Thiamine is important in the release of energy from carbohydrates and is also required for the synthesis of acetylcholine. Thiamine deficiency is associated with serious cardiac sequelae, including cardiomegaly associated with congestive heart failure and generalized edema. These signs and symptoms are usually preceded by generalized malaise characterized by sever fatigue, apathy, irritability, myalgia, anorexia, nausea, and abdominal distention. Central nervous system findings are numerous and include peripheral neuritis, paresthesias, decreased deep tendon reflexes, and ataxia. Severe deficiency leads to beriberi, which is characterized by edema leading to a “waxy” appearance of the skin, respiratory distress, and increased heart rate in an undernourished child (“wet” beriberi) or by a more plump-appearing listless child with dyspnea, increased heart rate, and hepatomegaly (“dry” beriberi). Fatty degeneration of the myocardium leads to associated arrhythmias which may be fatal without nutritional intervention. Thiamine replacement results in dramatic improvement of cardiac symptoms with no associated permanent damage to the heart. Patients often have deficiencies in one or more of the other B-complex vitamins. Board Testing Point: Recall the clinical signs and symptoms associated with specific vitamin deficiencies. __________________________________________________________________________________________

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