Cardiology

A 15-day-old infant with respiratory distress is brought into the emergency department. A quick observation suggests that the in­fant has slight cyanosis, hepatosplenomegaly, and features consis­tent with Down syndrome. The cardiac examination demonstrates a loud first heart sound, a wide and fixed split second heart sound, a low-pitched, mid-diastolic murmur at the lower left sternal bor­der, and a harsh apical holosystolic murmur in the mitral area. Which of the following cardiac conditions is most likely to explain the heart defect in this infant with probable Down syndrome?

  1. Complete atrioventricular (A-V) canal (endocardial cushion defect)
  2. Transposition of the great vessels
  3. Total anomalous venous return
  4. Hypoplastic left heart
  5. Tricuspid atresia

A. While ventricular septal defects are common heart defects in patients with Down syndrome, the most characteristic lesion is endocardial cushion defects. Slight cyanosis occurs because of the mixing of deoxygenated with oxygenated blood.

At her 2-month-old well-child examination, an infant girl with Down syndrome is noted to have both a systolic and a diastolic heart murmur, and the second heart sound is split. The liver edge is palpable 4 cm below the right costal margin. Her mother reports that lately the baby has been sweaty and sometimes bluish around the mouth when she nurses, and she seems to be eating less than previously. The most likely diagnosis is:

  1. Ventricular septal defect
  2. Atrial septal defect
  3. A V canal defect
  4. Patent ductus arteriosus
  5. Patent foramen ovale

C. AV canal is common among children with Down syndrome This infant’s symptoms and clinical findings are most consistent with this diagnosis.

A 4-month-old boy with a moderate-sized ventricular septal de­fect presents to the emergency center with a 12-hour history of multiple episodes of vomiting and diarrhea. His temperature is 101.8°F (38.8°C) rectally, his heart rate is 120 beats per minute, and he is normotensive. His mucous membranes appear dry, and his capillary refill is 3 seconds. His mother reports that his last wet diaper was 5 hours prior. Two intravenous infusions of 20 cc/kg normal saline are administered over a 1-hour period. Following the fluid boluses, the child’s mucous membranes and capillary refill have improved, but he develops an increased respiratory rate. The most likely explanation for the increased res­piratory rate is:

  1. Pulmonary congestion
  2. Pneumonia
  3. Pneumonitis
  4. Bronchiolitis
  5. Bronchitis

A. Pulmonary vascular congestion (“fluid overload”) is a poten­tial complication of intravenous fluid administration in any pa­tient. Persons with cardiac lesions that involve a left-to-right shunt are at particular risk for this problem. Diuretic adminis­tration (furosemide) may be required if the respiratory distress is significant.

A 4-year-old boy presents for the first time to a family practice clinic for a routine well-child visit. On review of systems, his mother notes that he breathes fast and his lips turn “dusky” when he runs or plays hard. The symptoms resolve once he stops the activity. On physical examination, the boy is noted to have a II/VI systolic murmur at the left upper sternal border that radiates to the back, and a faint click is heard. What is the most likely cause of this child’s exercise intolerance?

  1. Asthma
  2. Ventncular septal defect
  3. Atrial septal defect
  4. Pulmonary valve stenosis
  5. Tricuspid atresia

D. Although both pulmonary stenosis and tricuspid atresia are cyanotic heart lesions, the clinical presentation of exercise ­induced cyanosis and systolic murmur are characteristic of pul­monary stenosis.

A 15-month-old child is playing with blocks in a squatting posi­tion in the clinic waiting room. The skin around her mouth is faintly blue, but she appears comfortable. She then begins running after her 3-year-old brother, when she suddenly becomes dyspneic and cyanotic She returns to a squatting position and soon is breathing comfortably again with only slight perioral cyanosis. You expect to see the following on her chest radiograph:

  1. A “boot-shaped” heart
  2. An “egg on a string”
  3. Pneumonia
  4. Pulmonary congestion
  5. Lung hyperinflation

A. This child has tetralogy of Fallot, with improvement when squatting, and “tet” (hypercyanotic) spells when running. The “boot shaped heart” is a characteristic chest radiographic finding.

which of the following children with Kawasaki disease is at greatest risk for the development of coronary artery disease?

  1. 5-year-old boy with 6 days of high fever, sterile pyuria, a truncal rash, and strawberry tongue
  2. 3-year-old girl with 5 days of high fever and cerebrospinal fluid pleocytosis
  3. 2-year-old girl with 5 days of high fever and an initial ESR of 80
  4. 1 year-old boy with 6 days of high fever, a maculopapu­lar diaper rash, and mildly elevated hepatic transaminases
  5. 6-month-old boy with 11 days of high fever .and a small pericardial effusion on initial echocardiogram

E. Risk factors for development of coronary aneurysms include male sex, prolonged fever for more than 10 days, age younger than 12 months, low serum albumin or hemoglobin, early car­diac findings (e.g. mitral regurgitation or pericardial effusion), and thrombocytosis.

A 12-year-old boy presents to his pediatrician for a sports physical examination. He denies any chronic health problems; eluding any adverse symptoms with exertion. The clinician notes: An I-II/VI systolic murmur at the left upper sternal border that does not radiate. The second heart sounds splits normally and no audible click is appreciated. Peripheral perfusion is normal, and the fingers are not clubbed. What should the clinician recommend to this patient?

  1. He should not play any strenuous sport.
  2. He may participate in sports without restrictions.
  3. He should have a chest radiograph and an ECG before further recommendation can be made.
  4. He should be evaluated by a cardiologist.
  5. He may participate in sports activities, but should seek immediate medical attention if he experiences dyspnea or other adverse symptoms.

B. This child has a benign pulmonary flow murmur. It is differ­entiated from a pathologic pulmonary murmur by the fact that it does not radiate, there is no click, and there are no signs and symptoms of cardiac disease such as digital clubbing, cyanosis, and exercise intolerance.

A 15 month old child is on long term aspirin therapy for coronary abnormalities that resulted from Kawasaki disease. In addition to his routine vaccinations he should receive a

  1. pneumococcal vaccine
  2. influenza vaccine
  3. menigiococcal vaccine
  4. oral polio vaccine
  5. varicella vaccine.

B. Children on prolonged aspirin therapy should receive the influenza vaccine because of the increased risk of Reye syndrome in those who become infected with the disease and take aspirin.

A 9-momh-old infant accidentally ingests an unknown quantity of digitalis. Which of the following is the most important noncardiac mani­festation of toxicity in this infant?

A. Fever

B. Dizziness

C. Vomiting

D. Visual disturbances

E. Urticaria

The answer is c. An impor­tant noncardiac manifestation of digitalis toxicity in infants is vomiting. Affected infants also exhibit electrocardiographic changes, including sinus arrhythmia (bradycardia) and a wandering pacemaker, paroxysmal tachy­cardia, and a heart rate of less than 100 bpm. The commonly used digitalis preparation in infants is digoxin. Digoxin blood levels of 2 ng/dL or less are usually therapeutic in adults: in contrast, therapeutic digoxin blood levels in infants range from 1 to 5 ng/dL, but the Benefit of the higher levels in infants is doubtful.

You are seeing a 2-year-old boy for the first time: his previous health care had been provided at a neighborhood “free immunization” clinic. His father denies any past medical or surgical history, but does note that the child’s day care recently sent a note home asking about several episodes usually after the child does not get what he wants, when he ‘breathe; funny” and sits in a corner with his knees under his chin for a few minutes. The parent day are staffers think this “self-imposed time-out” is a good thing, but they worry about the breathing. One teacher even though he once looked blue but detected that it was probably due to the finger paints he had been using. On examination, you identify a right ventricular impulse, a systolic thrill along the left sternal border, but radiating through the lung fields). Which of the following cardiac lesions would you expect to find in this child?
a. ventricular septal defect
b. Right ventricular outflow obstruction
c. Atrial septal detect
d. Transposition of the great vessels with a patent foramen ovale
e. Hypoplastic left heart.

The answer is b. This child has tetralogy of Fallot, which consists of right ventricular outflow obstruction (pulmonary stenosis), ventricular septal defect, dextroposition of the aorta, and right ventricular hypertro­phy. Children with tetralogy of Fallot may have cyanotic episodes (“tet spells”) associated with acute reduction in pulmonary blood flow. Typically, these spells are self-limited, lasting no more than 30 minutes. A child’s assuming the knee-chest position is thought to increase peripheral resis­tance, decreasing the amount of right-to-left shunting and thus increasing pulmonary blood flow. Alternative therapies include morphine sulfate and propranolol. Prolonged hypoxia can lead to acidosis; correction may require infusion of sodium bicarbonate.

The parents of a 2-month old boy are concerned about his risk of coronary artery disease because of the recent death of his 40-year-old maternal uncle from a myocardial infarction. which of the following is the most appropriate management in this situation?
a Screen the parent for total cholesterol.
b. Counsel the parent about appropriate dietary practice for a 2-month-old infant
c. Reduce the fat to less than 30% of his calories by giving him
skim milk
d. Initiate lipid-lowering
e. Recommend yearly ECG for the patient.

The answer is a. Identification of those with a genetic predisposition to hypercholesterolemia and of the factors that increase the risk of the condition is recommended so that dietary and other measures to reduce serum lipids can be introduced if indicated. Children with a first- or second-degree relative with early onset of coronary heart disease should be evaluated early in life but after 2 years of age. Other known risk factors include obesity, diabetes, hypertension, and smoking. No change in cur­rent infant dietary practice is recommended for children under 2 years of age. The high total fat content of the infant diet is considered to be bio­logically sound, given the need for lipid for a developing nervous system and the infant’s limited capacity for an intake of high volume during this period of rapid growth. It is generally agreed that a dietary fat intake of 40% of calories is excessive over the age of 2 years. There is, however, con­cern about the potential loss of minerals such as iron, zinc, and calcium when dietary fat is reduced below 30% of calories in children 2 to 18 years of age. Principal sources of fat in the American diet are meat and milk, which are also sources of minerals such as iron and calcium. Simple mod­ifications in the current U.S. diet of children of these ages (trimming excess fat from meat and drinking 1% fat milk) would effect a reduction of fat intake by 5% of calories without the risk of lowering mineral intake. It would be helpful in this situation to determine whether the uncle had hypercholesterolemia. Yearly ECGs and lipid-lowering agents are not indi­cated in this situation.

A 15-year-old girl with short stature, neck webbing, and sexual infantilism is found to have coarctation of the aorta. A chromosomal analy¬sis likely would demonstrate which of the following?
a. Mutation at chromosome 15q21.1
b Trisomy 21
c. 45 X karyotype
d. Detect chromosome 4p 16
e Normal chromosome analysis

The answer is c. Short stature, neck webbing, sexual infantilism, and a shield like chest with widely spaced nipples are signs of Turner syn­drome, which is usually associated with an 45X karyotype. Aortic coarctation occurs in about 15 to 20% of those with this disorder. Down syndrome is most commonly associated with endocardial cushion defects or ventric­ular septal defect. Marfan syndrome (mutation 15q21.1) is associated with dilatation of the aorta and mitral and aortic regurgitation. Ellis-van Creveld syndrome (defect 4pl6) is associated with atrial septal defects.

A newborn is diagnosed with congenital heart disease. You counsel the family that the incidence of heart disease in future children is which of the following?
a. 1%
b. 2 to 6%
c. 8 to 10%
d. 15 to 20%
e. 25 to 30 %

The answer is b. The incidence of congenital heart disease in the population is about 1%. The risk of congenital heart disease in a family with one child born with heart disease varies depending on the type of lesion the first child had, but, overall, the rate averages from about 2 to 6% if the heart dis­ease is not associated with a diagnosable syndrome. The risk of congenital heart disease for an infant is increased if there is a history of congenital heart disease in the mother. If two children with congenital heart disease are diagnosed, the risk escalates to 20 to 30%.

During a regular checkup of an 8-year-old child, you note a loud first heart sound with a fixed and widely split second heart sound at the upper left sternal border that does not change with respirations. The patient is otherwise active and healthy. Which of the following heart lesions most likely explains these findings?
a. Atrial septal defect
b. Ventricular septal defect
c. Isolated tricuspid regurgitation
d. Tetralogy of Fallot
e. Mitral valve prolapse

The answer is a. Most commonly, children with an atrial septal defect (ASD) are asymptomatic, with the lesion being found during a routine examination. In older children, exercise intolerance can be noted if the lesion is of significant size. On examination, a right ventricular systolic lift at the left sternal border is palpable . a fixed splitting of the second heart sound is audible. For lesser degrees of ASD, surgical treatment is more controversial. Ventricular septal defeats commonly present as a harsh or blowing holosystolic murmur best heard along the left lower sternum, often with radiation throughout the precordium. Tricuspid regurgitation is a middiastolic rumble at the lower left sternal border; a history of birth asphyxia or findings of other cardia lesions often is present. Tetralogy of Fallot is a common form of congenital heart disease. The four abnormalities include right ventricular outflow obstruction, ventricular septal defect, dextroposition of the aorta, and right ventricular hypertrophy. The cyanosis presents in infants and in young children. Mitral valve prolapse occurs with the billowing into the atria one or both mitral valve leaflets at the end of systole. It is a congenital abnormality that frequently manifests only during adolescence or later. It is common in girls than in boys and seems to be inherited in an auto dominant fashion. On clinical examination, an apical murmur is late in systole, which can be preceded by a midsystolic click. The diagnosis is confirmed with an echocardiogram that shows prolapse of the mitral leaflets during mid- to late systole. Antibiotic, prophylaxis is recom­mended for dental work (especially if a murmur is present as the inci­dence of endocarditis can be higher in these patients.

A 3-month-old infant is brought to your office for pallor and listlessness. Your physical examination reveals a heart rate of 280 bpm. He has no hepatomegaly and the lungs are clear. Your electrocardiogram reveals P waves before each QRS complex, but an abnormal P wave axis. The heart rate is consistent and does not vary with crying. Which of the following is the most appropriate initial management of this patient?
a. Rapid verapamil infusion
b. Transthoracic pacing of the heart
c. Vagal nerve stimulation
d. DC cardioversion
e. Precordial thump

The answer is c. (Supraventricular tachycardia is characterized by rapid heart rate, little rate variability, and a consistent P wave for each QRS complex. Prolonged SVT can lead to heart failure with hepatomegaly and respiratory compromise. Fetal SVT can lead to hydrops fetalis. The first-line treatment is to stimulate the vagus nerve using techniques such as immersion of the face in cold water or voluntary straining. Rapid infusion of IV adenosine can affect resolution if the maneuvers are not successful. Verapamil is contraindicated in this age group, as it may cause acute hypotension and cardiac arrest. Synchronized DC cardioversion may be performed in patients in shock or with heart failure; it must, however, be synchronized to the QRS complex. Transthoracic pacing is typically useful in bradyarrhythmias. A precordial thump would help individuals with an acute arrest from ventricular fibrillation, but does not resolve SVT.

An ill-appearing 2-week-old girl is brought to the emergency room. She is pale and dyspneic with a respiratory rate of 80 breaths per mm. Heart rate is 195 bpm. heart sounds are distant, a gallop is heard, and she has cardiomegaly on x-ray. An echocardiogram demonstrates poor ventric¬ular function, dilated ventricles, and dilation of the left atrium. An electro¬cardiogram shows ventricular depolarization complexes that have low voltage. which of the following is the most likely diagnosis based on this clinical picture?
a. Myocarditis .
b. Endocardial fibroelastosis
c. Pericarditis
d. Aberrant left coronary artery arising from pulmonary artery
e. Glycogen storage disease of the heart

The answer is a. The findings of pallor, dyspnea, tachypnea. tachycardia, and cardiomegaly are common in congestive heart failure regardless of the cause. The most common causes of myocarditis include adenovirus and coxsackievirus B, although many other viruses can cause this condition. The constellation of findings in the question point to myocarditis as the etiology of this patient’s condition. The lack of echocardiographic findings, other than ventricular and left atrial dilatation and poor ventricular function, is inconsistent with both glycogen storage dis­ease of the heart Un which there is muscle thickening) and pericarditis (since there is no pericardia! effusion). It is also not consistent with an abnormal origin of the left coronary artery, although the origin of the coronary arteries can be more easily missed. On electrocardiogram, the voltages of the ventricular complexes seen with aberrant origin of the left coronary artery are not diminished and a pattern of myocardial infarction can be seen. Voltages from the left ventricle are usually high in endocardial fibroelastosis, and Both right and left ventricular forces are high in glycogen storage disease of the heart.

A newborn infant has mild cyanosis, diaphoresis, poor peripheral pulses, hepatomegaly, and cardiomegaly. Respiratory rate is 60 breaths per min, and heart rate is 250 bpm. The child most likely has congestive heart failure caused by which of the following?
a. A large atrial septal defect and valvular pulmonic stenosis
b. A ventricular septal defect and transposition of the great vessels
c. Total anomalous pulmonary-venous return
d. Hypoplastic left heart syndrome
e. Paroxysmal atrial tachycardia

The answer is e. Congestive heart failure from any cause can result in mild cyanosis, even in the absence of a right-to-left shunt, and in poor peripheral pulses when cardiac output is low. Conges­tive heart failure from many causes can be associated with a rapid pulse rate (up to 200 beats per min). A pulse rate greater than 250 beats per mm, however, should suggest the presence of a tachyarrhythmia. Common causes for supraventricular tachycardia includes Wolff-Parkinson-White (WPW) syndrome, congenital heart disease, and sympathomimetic drugs. In this patient, evaluation for WPW and cardiac abnormalities must be accomplished after the congestive heart failure from the increased heart rate is under control.

A child has a 2-week history of spiking fevers, which have been as much as 40°C (104°F). She has spindle-shaped swelling of finger joints and complains of upper sternal pain. When she has fever, the parents note a faint salmon-colored rash that resolves with the resolution of the fever. She has had no conjunctivitis or mucositis, but her heart sounds are muffled and she has increased pulsus paradoxus. Which of the following is the most likely diagnosis?
a. Rheumatic fever
b. Juvenile rheumatoid arthritis
c. Toxic synovitis
d. Septic arthritis
e. Osteoarthritis

The answer is b. Juvenile rheumatoid arthritis (JRA, or Still’s disease) frequently causes spindle-shaped swelling of finger joints and can involve unusual joints such as the sternoclavicular joint. Presentation of JRA occurs as either polyarthritis (five or more joints, systemic symptoms not so severe or persistent), pauciarticular (four or fewer joints, lower-extremity joints, extra-articular disease unusual), or systemic disease (severe constitutional disease, systemic symptoms prior to arthritis, rheumatoid rash, high spik­ing fevers, variable joint involvement). This disorder can be associated with spiking high fevers and diffuse rash, which are not a feature of rheumatic fever, toxic synovitis, or osteoarthritis. Although septic arthritis can affect any joint, it would not be likely to affect finger joints by causing spindle-shaped swellings. Toxic synovitis usually involves larger joints, such as the hip, and osteoarthritis is not a disease of childhood.

A cyanotic newborn is suspected of having congenital heart disease. He has an increased left ventricular impulse and a holosystolic murmur along the left sternal border. The EGG shows left axis deviation and left ventricular hypertrophy (LVH). Which of the following is the most likely diagnosis?
a. Transposition of the great arteries
b. Truncus arteriosus
c. Tricuspid atresia
d. Tetralogy of Pallet
e. Persistent fetal circulation

The answer is c. Patients with tricuspid atresia typically have a hypoplastic right ventricle, and therefore the ECG shows left axis deviation and left ventricular hypertrophy; this translates to a left ventricular impulse on physical examination. Almost all other forms of cyanotic congenital heart disease are associated with elevated pressures in the right ventricle and increased right ventricular impulse. In those conditions, therefore, the ECG will show right axis deviation and right ventricular hypertrophy.

During a physical examination for participation in a sport, a 16-year-old girl is noted to have a late apical systolic murmur, which is preceded by a click. The rest of the cardiac examination is normal. She states that her mother also has some type of heart “murmur” but knows nothing else about it. Which of the following is the most likely diagnosis?
a. Atrial septal defect
b. Aortic stenosis
c. Tricuspid regurgitation
d. Mitral valve prolapse
e. Ventricular septal defect

The answer is d. Mitral valve prolapse occurs with the billowing into the atria of one or both mitral valve leaflets at the end of systole. It is a congenital abnormality that frequently manifests only during adolescence or later. It is more common in girls than in boys and seems to be inherited in an autosomal dominant fashion. On clinical examination, an apical mur­mur is noted late in systole, which can be preceded by a click. The diagno­sis is confirmed with an echocardiogram that shows prolapse of the mitral leaflets during mid- to late systole. The ECG and chest x-ray are usually normal. Beta blockers and digitalis are unlikely to be required, but peni­cillin prophylaxis for dental procedures for patients with mitral valve pro­lapse, especially if a murmur is present, is indicated.

A 3-day-old infant with a single second heart sound has had pro-gressively deepening cyanosis since birth but no respiratory distress. Chest radiography demonstrates no cardiomegaly and normal pulmonary vasculature. An electrocardiogram shows an axis of 120° and right ventricular prominence. Which of the following congenital cardiac malformations is most likely responsible for the cyanosis?
a. Tetralogy of Fallot
b. Transposition of the great vessels
c. Tricuspid atresia
d. Pulmonary atresia with intact ventricular septum
e. Total anomalous pulmonary venous return below the diaphragm

The answer is b. Transposition of the great vessels with an intact ventricular septum presents with early cyanosis, a normal-sized heart (clas­sic “egg on a string” radiographic pattern in one-third of cases), normal or slightly increased pulmonary vascular markings, and an electrocardiogram showing right axis deviation and right ventricular hypertrophy. In tetralogy of Fallot, cyanosis is often not seen in the first few days of life. Tricuspid atresia, a cause of early cyanosis, causes diminished pulmonary arterial blood flow; the pulmonary fields on x-ray demonstrate a diminution of pulmonary vasculanty, and left axis and left ventricular hypertrophy are shown by electrocardiogram. Total anomalous pulmonary venous return below the diaphragm is associated with obstruction to pulmonary venous return and a classic radiographic finding of marked, fluffy-appearing venous congestion (“snowman”). In pulmonic atresia with an intact ven­tricular septum, cyanosis appears early, the lung markings are normal to diminished, and the heart is large.

A previously normal newborn infant in a community hospital nurs-ery is noted to be cyanotic at 14 h of life. She is placed on a face mask with oxygen flowing at 10 LPM. She remains cyanotic, and her pulse oximetry reading does not change. An arterial blood gas shows her Pao2 to be 23 mmHg. Bilateral breath sounds are present, and she has no murmur. She is breathing deeply and quickly, but she is not retracting. You are concerned about congenital heart disease. While you are waiting for the transport team from the nearby children’s hospital, you should initiate which of the following?
a. Indomethacin infusion
b. Saline infusion
c. Adenosine infusion
d. Prostaglandin Et infusion
e. Digoxin infusion

The answer is d. The vignette describes an infant with a ductal-dependent cyanotic congenital heart lesion. In this example, the child had pulmonary atresia without a corresponding ventricular septal defect; another example would have been transposition of the great vessels without a septal defect to allow mixing of oxygenated and non-oxygenated blood. Cyanotic infants who do not improve their saturations with supplemental oxygen should be evaluated carefully for structural heart dis­ease. The ductus arteriosus typically closes in the first few hours of life; thus, these children will develop their cyanosis in the same time frame.

Prostaglandin E, will help keep the ductus patent until a surgical procedure can be performed. PGE1 does have the tendency to cause hypoventilation, so arrangements must be made for a potential artificial airway if necessary. Indomethacin closes a patent ductus arteriosus. Adenosine is used for supraventricular tachycardia.