Cardiology

Question 1

A 7-year-old presents with:

• Hypertension
• Radial pulses that are strong compared to the femoral pulses
• Rib notching on CXR

What is the most likely diagnosis?

Answer 1

Coarctation of the Aorta (CoA)

CoA is an obstructive lesion found in otherwise asymptomatic older children and young adults during a workup of hypertension or murmur. If the obstruction is severe, it can present in newborns as heart failure or cardiogenic shock.

Question 2

What syndrome is associated with true interruption of the aortic arch?

Answer 2

DiGeorge Syndrome

DiGeorge syndrome is associated with a true interruption of the aortic arch. The FISH test (22q11 marker) is commonly asked about as the diagnostic test for DiGeorge.

Question 3

What cardiac condition is associated with Williams syndrome?

Answer 3

Supravalvular Aortic Stenosis (AS)

Williams syndrome is associated with supravalvular AS, which is narrowing just above the level of the coronary arteries. Other arteries may also be narrowed in Williams syndrome, including the pulmonary arteries and the renal arteries.

Question 4

A high school basketball player passes out and dies while playing a game. Hypertrophic cardiomyopathy is ruled out as a cause.

What is the next most likely cause of sudden death in an exercising adolescent?

Answer 4

Anomalous Origin of Left Coronary Artery from the Opposite Cusp

This occurs when the left (most commonly) or right coronary arteries come off the opposite coronary cusp and pass between the aorta and the pulmonary artery. With exercise, both the aorta and pulmonary artery dilate, which can “squish” the misplaced coronary artery and cut off its circulation, resulting in syncope and sudden death.

Question 5

A newborn presents with cyanosis of the fingers and hands, but not of the toes or feet.

What cardiac condition does this indicate?

Answer 5

Transposition of the Great Arteries

Cyanosis of the fingers/hands, but not of the toes/feet, is termed “reverse differential cyanosis.” This indicates transposition of the great arteries, with right-to-left shunting of saturated blood through the ductus.

Question 6

Lithium use in pregnancy is associated with what cardiac abnormality?

Answer 6

Ebstein Anomaly (EA) of the Tricuspid Valve

EA is rare but is associated with lithium use by pregnant women. With EA, the posterior and septal leaflets of the tricuspid valve are displaced downward and attached to the right ventricle wall. Look for a huge right atrium on ECG with wall-to-wall heart shadow on CXR.

Question 7

On an ECG, you note normal PR intervals, but following every other P wave, there is a dropped QRS (ventricular beat).

What is the conduction disturbance here?

Answer 7

2° atrioventricular (AV) Block, Mobitz 2

Mobitz 2 and higher-grade heart block implies disease of the His-Purkinje conduction system and is abnormal. Pacemakers may be required if the patient is symptomatic or if average heart rates are very low.

Question 8

A 7-year-old boy presents for a camp physical. The following is found:

• Systolic ejection murmur with a vibratory character
• The murmur is heard best in lower precordium and not in the back.
• The murmur decreases with positional changes that decrease venous return.

What is the most likely murmur?

Answer 8

Still’s Murmur

Still’s murmur is very common in childhood. It usually has a musical quality, and some say it sounds like a plucked-string instrument or a kazoo. It is the most common innocent murmur in children beyond the newborn period.

Question 9

On an ECG, you see progressive prolongation of the PR interval until there is a dropped QRS (ventricular beat).

What is this type of conduction disturbance called?

Answer 9

Mobitz 1 (a.k.a. Wenckebach)

This type of 2° atrioventricular (AV) block is primarily from vagal tone on the AV node and is generally not progressive or malignant. It rarely requires treatment.

Question 10

An ECG is done on a 2-week-old boy because of a possible enlarged heart. The ECG shows tall R wave and negative T wave in lead V6.

What do these findings infer?

Answer 10

Left Ventricular Hypertrophy (LVH)

A tall R wave in V6 is consistent with LVH, and the negative T wave after 7 days of life is consistent with LVH with strain.

Question 11

A child has the following findings on echo:

• The anatomic left ventricle ends up on the right side and receives deoxygenated blood from the right atrium through a mitral valve, while the left ventricle ejects blood to a posteriorly placed pulmonary artery.
• The anatomic right ventricle is on the left side and receives oxygenated blood from the left atrium through a tricuspid valve, while the right ventricle ejects blood to an anteriorly placed left-sided aorta.

What is this described cardiac condition?

Answer 11

l-Transposition of the Great Arteries (l-TGA), a.k.a. Ventricular Inversion or Congenitally Corrected TGA

l-TGA occurs when the embryonic cardiac tube loops to the left instead of the right. The result is transposition of the great arteries (the aorta is anterior and comes off the anatomic right ventricle, and the pulmonary artery comes off the anatomic left ventricle) and “inversion” of the ventricles, but this allows normal flow of venous blood to the lungs and oxygenated blood to the rest of the body. Thus, this is known as “congenitally corrected” transposition.

Question 12

What is the most common cardiac cause of cyanosis presenting in the first few days of life?

Answer 12

Complete d-Transposition of the Great Arteries (d-TGA)

Remember that tetralogy of Fallot is the most common cyanotic cardiac lesion for all ages of children, but complete d-TGA is the most common to present in the first few days of life.

Question 13

A 12-year-old is referred by a school nurse for murmur evaluation:

• S₁ is normal.
• S₂ is widely split and does not vary with respiration.
• The murmur is a systolic ejection murmur that is crescendo-decrescendo and heard best at the upper left sternal border.
• CXR and ECG both show right atrial (RA) and right ventricular (RV) enlargement and right axis deviation (RAD).

What is the most likely diagnosis?

Answer 13

Ostium Secundum Type of Atrial Septal Defect (ASD)

Ostium secundum defects are the most common form of ASD and are located in the midseptum. Classically, look for the “fixed split” S₂—commonly described as “S₂ is widely split without respiratory variation.” Right atrial hypertrophy (RAH) and right ventricular hypertrophy (RVH) are also common with long-standing disease. Differentiate the ostium secundum defect from the ostium primum defect by finding left axis deviation (LAD) in the latter and RAD in the former. (The ostium primum defect may also present with physical findings of mitral insufficiency). ASDs are twice as common in females as in males.

Question 14

What is the most common heart defect in Down syndrome (trisomy 21)?

Answer 14

Complete Atrioventricular (AV) Canal Defect

Complete AV canal defect (a.k.a. endocardial cushion or AV septal defect) is frequently seen in children with trisomy 21. Complete AV canal defect involves failure of the “central” heart to develop, resulting in a large hole communicating between the atria and ventricles, as well as malformation of the tricuspid and mitral valves. These infants most often present with heart failure by 2 months of age.

Question 15

A 4-day-old newborn presents in apparent septic shock, but on exam and laboratory, you find:

• Systolic murmur at the right upper sternal border
• Early ejection click
• Pulses are diminished.
• CXR shows marked cardiomegaly with severe pulmonary edema.

What is the most likely cardiac abnormality?

Answer 15

Aortic Stenosis (AS)

The infant with severe congenital AS presents early with a systolic murmur at the right (or left) upper sternal border, with an early ejection click. Perfusion and pulses are diminished, and the infant appears to be in septic shock. Administration of PGE1 can be helpful by opening the ductus to provide blood flow to the aorta. This is followed by either balloon angioplasty of the aortic valve or surgical valvuloplasty.

Question 16

A 12-year-old girl presents with:

• Sudden onset of severe, sharp chest pain that is localized to the cardiac apex
• This is the 6th episode; it occurred in the last 2 days.
• Each episode lasts from 30 seconds to 2–3 minutes and then resolves.
• It usually occurs at rest.
• It seems to be worse if she takes in a deep breath.

What is the likely diagnosis?

Answer 16

Precordial Catch (Benign Chest Wall Pain)

Precordial catch is one of the most common causes of chest pain in older children and adolescents. Its etiology is unknown. The condition is benign.

Question 17

Name the 4 abnormalities that make up tetralogy of Fallot (TOF).

Answer 17

Right Ventricular Outflow Tract Obstruction (Subpulmonary Valve Stenosis), VSD, Overriding Aorta, and Right Ventricular Hypertrophy

TOF is the most common cyanotic heart lesion in children with congenital heart disease who have survived untreated beyond infancy. It makes up 7–10% of congenital heart defects.

Question 18

What is the most common benign murmur of infancy?

Answer 18

Physiologic Peripheral Pulmonary Stenosis (PPS)

Physiologic PPS is the most common murmur of infancy and is not pathological. The murmur is due to turbulence caused by 2 factors: 1) the branch pulmonary arteries being smaller compared to the main pulmonary artery, 2) the sharp angle of origin of the branch arteries off the main pulmonary artery. A soft, harsh systolic ejection murmur is best heard at the axillae and both the right and left hemithoraces. By 12 months of age the branch pulmonary arteries become larger and the angle of origin off the main pulmonary artery widens, causing the murmur to disappear.

Question 19

A 4-month-old infant presents with tachycardia and respiratory distress. An ECG is done and shows a narrow complex rhythm with a rate of 240 bpm.

What maneuver can be done to slow the ventricular rate and potentially return the child to normal sinus rhythm?

Answer 19

Diving Reflex—Place an Ice Bag on the Infant’s Face for

10–20 Seconds

Supraventricular tachycardia (SVT) is the most common tachycardia in children. Vagal maneuvers (the diving reflex as described here with ice) are commonly useful in getting children out of this arrhythmia. If this is not successful, use adenosine. If the child is unstable, treat with direct current (DC) cardioversion. Avoid verapamil in infants < 1 year of age!

Question 20

A 15-year-old boy presents with a history of palpitations. He is otherwise asymptomatic, and his physical examination is normal. An ECG is done, which is normal, as well as a 3-minute rhythm strip. During the rhythm strip, he has multiple, simple premature ventricular contractions (PVCs).

What is the best treatment for this boy?

Answer 20

Reassurance

Simple PVCs do not require any therapy except reassurance or avoidance of precipitating factors such as caffeine.

Question 21

A 17-year-old “falls out” while playing basketball. On exam, you find the following:

• Grade 4/6 crescendo-decrescendo systolic murmur at the right upper sternal border
• No palpable thrill
• The murmur gets louder with Valsalva or standing up from a supine position.
• Left ventricular hypertrophy on ECG

What is the most likely diagnosis?

Answer 21

Hypertrophic Cardiomyopathy (HCM)

HCM is an autosomal dominant disorder with variable expression. It is the most common cause of sudden death in exercising young people. Murmurs are systolic, and can be either ejection or holosystolic, depending on the acuity and severity of the obstruction. The murmur of HCM is usually best heard at the left sternal border with potential radiation up to the aortic area, depending on the acuity and degree of obstruction. If heard in the aortic area, the murmur must be distinguished from the murmur of aortic stenosis (AS), which has a very similar loud murmur at the right upper sternal border. In HCM, Valsalva and standing increase the murmur, while in AS, these maneuvers decrease the murmur. The ECG is almost always abnormal, demonstrating left ventricular hypertrophy.

Question 22

An 8-hour-old infant presents with:

• Cyanosis
• Diminished pulmonary blood flow on CXR
• Left superior axis deviation and left ventricular hypertrophy with small right ventricular forces on ECG

What is the most likely diagnosis?

Answer 22

Tricuspid Atresia

Tricuspid atresia presents with cyanosis as its key presenting sign and occurs within hours of birth, when the patent ductus arteriosus begins to close. This differs from the 2 other common cyanotic diseases (tetralogy of Fallot [TOF] and dextro-transposition of the great arteries [d-TGA]) because of the presence in tricuspid atresia of left superior axis deviation and left ventricular hypertrophy—not right axis deviation and right ventricular hypertrophy, as seen in TOF and d-TGA.

Question 23

What is the most common congenital heart lesion?

Answer 23

Ventricular Septal Defect (VSD)

VSD is a left-to-right shunt defect where blood from the systemic (left) ventricle shunts to the pulmonary (right) ventricle by an abnormal connection. It is the most common congenital heart defect recognized in the first few years of life and makes up 25–30% of cases of congenital heart lesions in term newborns. Pulmonic stenosis, atrial septal defect, and patent ductus arteriosus are next most common.

Question 24

A newborn presents with delay of the femoral pulse compared to the radial pulse.

What cardiac condition does this indicate?

Answer 24

Coarctation of the Aorta (CoA)

Abnormalities of arterial pulses can indicate significant cardiac anomalies. Significant delay or even absence of the femoral pulse, compared to the radial pulse, indicates CoA.

Question 25

What is the most common aortic arch abnormality?

Answer 25

Aberrant Right Subclavian Artery

The most common aortic arch abnormality is an aberrant right subclavian artery arising from the descending aorta, but it rarely causes symptoms. Look for complete or partial DiGeorge syndrome in infants with aortic arch abnormalities.

Question 26

In children, which is more likely to be abnormal—a 3^rd heart sound (S₃) or a 4^th heart sound (S₄)?

Answer 26

S₄

An S₃ can be normal in children, but an S₄ is almost always abnormal in children. An S₄ can be heard with aortic stenosis, mitral regurgitation, hypertrophic cardiomyopathy, and hypertension with left ventricular hypertrophy.

Question 27

What is the most common symptomatic aortic arch abnormality?

Answer 27

Double Aortic Arch

Double aortic arch (persistence of both right and left 4^th embryonic arches) is the most common anomaly to cause symptoms. The anomaly results in encircling of the trachea and esophagus, causing tracheal compression and respiratory symptoms. Look for complete or partial DiGeorge syndrome in infants with aortic arch abnormalities.

Question 28

What is the classic CXR finding in an infant with complete dextro-transposition of the great arteries (d-TGA)?

Answer 28

Egg-Shaped or Oval-Shaped Heart

CXR can vary from normal to the classic findings—egg-shaped or oval-shaped heart with a narrow mediastinum (due to the aorta being in front of the main pulmonary artery) and small thymus. This classic CXR finding, however, is only seen in about 33% of infants with complete d-TGA.

Question 29

A 13-year-old boy presents with:

• Mid- to late-systolic murmur at the apex
• The murmur is preceded by one or more “clicks.”
• If the patient goes from a supine to a standing position, the murmur gets louder; when he squats, the murmur becomes softer.

What is the most likely diagnosis?

Answer 29

Mitral Valve Prolapse (MVP)

MVP occurs when 1 or both leaflets of the mitral valve prolapses back into the left atrium in systole. So, for a mid- to late-systolic murmur that gets louder with standing, think MVP; on the other hand, for an early systolic murmur that gets louder on standing, think hypertrophic cardiomyopathy.

Question 30

A 4-week-old infant presents with:

• “Breathing fast”, according to the mother
• A holosystolic murmur that is high-pitched, heard best at the lower-left sternal border
• A palpable thrill

What is the most likely diagnosis?

Answer 30

Ventricular Septal Defect (VSD)

VSD is a left-to-right shunt defect where blood from the systemic (left) ventricle shunts to the pulmonary (right) ventricle by an abnormal connection. It is the most common congenital heart defect recognized in the first few years of life, making up 25–30% of cases of congenital heart lesions in term newborns. VSD is initially detected by finding a murmur, commonly described as “harsh” or high pitched. If the infant presents at 3–4 weeks “breathing harder” and with a new murmur, think VSD. As the pulmonary resistance drops over the 1stmonth of life, more blood flows across the VSD, leading to heart failure.

Question 31

What cardiac condition has the classic CXR that shows a “snowman” or “figure-8” silhouette?

Answer 31

Total Anomalous Pulmonary Venous Return (Supracardiac)

Total anomalous pulmonary venous return occurs when the pulmonary veins go either to the right atrium (RA) or to other systemic veins that then drain into the RA. The majority of infants present early with tachypnea and FTT. The “snowman” finding occurs when the pulmonary veins drain into the left superior vena cava and blood flows into the innominate vein, where it finally enters the heart through the normal right superior vena cava.

Question 32

A 6-year-old girl presents with:

• Chorea
• Fever
• Elevated CRP
• Arthralgia

What is the most likely diagnosis?

Answer 32

Rheumatic Fever

To make a diagnosis of rheumatic fever, you must have either 2 major manifestations or 1 major and 2 minor manifestations. The patient has 1 major (chorea) and 3 minor (fever, elevated CRP, and arthralgia) manifestations. You must also confirm a recent or concurrent streptococcal infection with either a positive throat screen/culture or laboratory data (e.g., an elevated ASO titer).

Question 33

Peaked T waves are seen with which electrolyte abnormality?

Answer 33

Hyperkalemia

Potassium is vital for regulating the normal electrical activity of the heart. Hyperkalemia, a serum potassium concentration greater than the upper limit of the normal range, can result in large, peaked T waves. Progressive hyperkalemia causes the following ECG changes: 1) progressive lengthening of PR and QRS intervals, then 2) loss of P wave + QRS widening into sine wave, and finally 3) ventricular fibrillation or cardiac standstill.

Question 34

A 7-year-old boy presents with a continuous murmur with the following qualities:

• Low-pitched sound
• Absent when the patient is supine
• Turning of the head, Valsalva maneuver, or compression of the jugular vein make the murmur go away.

What is the most likely murmur?

Answer 34

Venous Hum

Venous hum is due to blood draining down the collapsed jugular veins into the larger intrathoracic veins. The high velocity makes the vein walls “flutter,” resulting in a low-pitched murmur. It is absent when the patient is supine because the neck veins distend and there is no pressure gradient between the 2 areas. Venous hum is an innocent murmur and very common in childhood.

Question 35

What diuretic causes hyperkalemia and, more rarely, gynecomastia?

Answer 35

Spironolactone

Spironolactone is the most commonly used potassium-sparing diuretic, but it can cause hyperkalemia, especially when supplementing potassium or using an ACE inhibitor. Additionally, it has neurohormonal effects that can result in gynecomastia.

Question 36

A child presents with mitral valve prolapse with a harsh, loud murmur.

What antibiotic prophylaxis does he require before his dental cleaning?

Answer 36

None

The guidelines changed in 2007. Now, only children with the following should receive antibiotic prophylaxis:

• Prosthetic heart valves
• Previous history of endocarditis
• Unrepaired cyanotic heart disease
• Completely repaired heart disease with prosthetic material or device for 6 months post-procedure
• Repaired congenital heart disease with a residual lesion
• Cardiac transplant recipients who develop a valvulopathy

Question 37

A 15-year-old boy presents with:

• Chest pain that is relieved by leaning forward
• Fever
• Pericardial friction rub
• ST-segment elevation in most leads with PR-segment depression in lead II on ECG

What is the most likely diagnosis?

Answer 37

Acute Pericarditis

Acute pericarditis is an inflammation of the parietal pericardium and superficial myocardium and occurs with rapid onset. Pericardial friction rub is virtually pathognomonic. Viral infections are the most likely cause in children.

Question 38

A 2-month-old girl presents with:

• Continuous “machinery-like” murmur that increases in intensity in late systole
• The murmur is heard best below the left clavicle, over the main pulmonary artery.

What is the most likely diagnosis?

Answer 38

Patent Ductus Arteriosus (PDA)

The ductus arteriosus normally closes within 10–15 hours of birth, although complete anatomic closure may not occur until 3 weeks. If the ductus remains open, it is called PDA. PDA can occur in all infants, and the cause is not always known. Premature infants (weighing < 1,750 g) have clinically apparent PDA ∼ 40–70% of the time. Children with PDA present with a continuous murmur, which is described as a “rumbling” or “machinery-like” murmur and commonly increases in intensity in late systole.

Question 39

An infant fails the newborn hearing screen and on ECG has a prolonged QT interval.

What is the likely diagnosis?

Answer 39

Jervell and Lange-Nielsen Syndrome

Jervell and Lange-Nielsen syndrome is an autosomal recessive disorder with deafness at birth and prolonged QT interval.

Question 40

Alagille and Noonan syndromes are both associated with what cardiac abnormality?

Answer 40

Pulmonary Stenosis (PS)

Alagille syndrome, caused by absence of or mutation in the JAG1 gene, primarily affects the liver but also has cardiac manifestations. They include peripheral and branch PS (67% of patients) and tetralogy of Fallot (7–16% of patients). Noonan syndrome is a genetic congenital disorder that affects many parts of the body. 50–60% of children with Noonan’s have PS.

Question 41

A 10-year-old boy presents as a new patient in your clinic with the following:

• Crescendo-decrescendo harsh systolic murmur, best heard at the right upper sternal border, which radiates into the suprasternal notch and neck
• Systolic ejection click at the apex
• Suprasternal notch thrill

What is the most likely diagnosis?

Answer 41

Aortic Stenosis (AS)

AS, when it is less severe, may be overlooked if the child is not examined carefully. As the child grows, symptoms may worsen, and the murmur and thrills become more prominent. However, realize that physical findings are not very reliable in predicting the severity of AS! A child with AS, especially if symptomatic (syncope, chest pain) needs to be referred for further evaluation (echo and/or cardiac catheterization). If significant AS is documented, follow with either balloon dilation of the aortic valve or surgery.

Question 42

An asymptomatic 10-year-old presents with:

• Systolic ejection click, which varies with respiration, along the left sternal border
• After the click, a crescendo-decrescendo murmur, best heard at the left upper sternal border
• The murmur radiates to below the left clavicle and to the back.
• ECG shows peaked P waves in lead II, right axis deviation, and right ventricular hypertrophy

What is the most likely diagnosis?

Answer 42

Pulmonary Stenosis (PS)

PS is the 2^nd most common congenital cardiac defect recognized early in life. The click and murmur are commonly the only abnormalities noted in a child with asymptomatic PS. Peaked P waves in lead II indicate right atrial enlargement. If the stenosis is mild, no therapy is required; if more severe, then these children commonly need pulmonary balloon valvuloplasty or surgical valvotomy.

Question 43

What is the most common cause of cardiac chest pain in children?

Answer 43

Pericarditis

Pericarditis is described as severe, substernal chest pain that is squeezing or tightening in character, and is the most common cause of cardiac chest pain in children. (Most chest pain in children is noncardiac!)

Question 44

A 14-year-old boy, newly adopted from Romania, presents for initial evaluation due to fatigue and exercise intolerance:

• You note a high-pitched, early diastolic decrescendo murmur that begins with the aortic component of the 2nd heart sound.
• There is a low-pitched, mid-diastolic murmur at the apex.

What is the most likely heart defect?

Answer 44

Aortic Regurgitation (AR)

AR presents with a high-pitched, early diastolic decrescendo murmur. If severe, it can be accompanied by an Austin Flint murmur (a low-pitched, mid-diastolic murmur at the apex, representing “relative” mitral stenosis) as well. Rheumatic fever is a major cause in Eastern European countries.

Question 45

A 15-month-old girl presents with 6 days of fever and the following:

• Conjunctival injection without discharge
• Erythema and edema of her hands and feet
• Erythema and cracked/peeling lips with a strawberry tongue
• Skin rash that is macular and widespread

What cardiac complication do you need to be concerned about in this girl?

Answer 45

Coronary Artery Aneurysms

These findings indicate a diagnosis of Kawasaki disease. Coronary artery aneurysms occur in 20–25% of untreated Kawasaki disease patients. Treatment is with IVIG infusion of 2 g/kg over 12 hours. Low-dose aspirin is also continued for at least 6–8 weeks.

Question 46

A 3-year-old child adopted from rural China presents with the following:

• Cyanosis on occasion
• Squats after exertion; cyanosis improves.
• Systolic murmur best heard at the left upper sternal border
• CXR shows a “boot-shaped” heart.
• ECG shows right axis deviation and right ventricular hypertrophy.

What is the likely diagnosis?

Answer 46

Tetralogy of Fallot (TOF)

TOF is typically found early in the U.S. and treated with corrective surgery by 6–12 months of age. However, an immigrant may present at an older age with unrepaired tetralogy. The 4 parts of TOF are: right ventricular outflow tract obstruction (this is what is responsible for the murmur!), VSD, overriding aorta, and right ventricular hypertrophy.