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)
Explanation
CoA is an obstructive lesion that can present in 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

A 13-year-old boy presents with:

Mid- to late-systolic murmur at the apex
The murmur is preceded by 1 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 2

Mitral valve prolapse (MVP)
Explanation
MVP occurs when 1 or both leaflets of the mitral valve prolapse 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 3

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

Answer 3

Answer
Right ventricular outflow tract obstruction (subpulmonary valve stenosis), ventricular septal defect, overriding aorta, and right ventricular hypertrophy
Explanation
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 4

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 4

Left ventricular hypertrophy (LVH)
Explanation
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 5

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 5

Answer
Aortic stenosis (AS)
Explanation
AS, when not critical, 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, treat with either balloon dilation of the aortic valve or surgery.

Question 6

Peaked T waves are seen with which electrolyte abnormality?

Answer 6

Hyperkalemia
Explanation
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, and finally 3) ventricular fibrillation or cardiac standstill.

Question 7

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

What cardiac condition does this indicate?

Answer 7

Coarctation of the aorta (CoA)
Explanation
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 8

What is the most common aortic arch abnormality?

Answer 8

Aberrant right subclavian artery
Explanation
The most common aortic arch abnormality is an aberrant right subclavian artery arising from the descending aorta, but it rarely causes symptoms. And remember, the most common vascular ring causing symptoms is double aortic arch.

Question 9

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 9

A vagal maneuver, the diving seal reflex—place an ice bag on the infant’s face for 10–20 seconds
Explanation
Supraventricular tachycardia is the most common tachycardia in children. Vagal maneuvers (the diving seal reflex as described here with ice) are useful in getting children out of this arrhythmia. If this is not successful, use IV adenosine. If the child is unstable, treat with direct current cardioversion. Avoid verapamil in infants < 1 year of age!

Question 10

What is the most common cardiac cause of cyanosis presenting in the 1st few days of life?

Answer 10

Dextrotransposition of the great arteries (d-TGA)
Explanation
Remember that tetralogy of Fallot is the most common cyanotic cardiac lesion for all ages of children, but d-TGA is the most common to present in the 1st few days of life.

Question 11

A 12-year-old girl presents with:

A history of episodes of severe, sharp chest pain over the anterior left chest wall
This is the 6th episode in the past 2 months.
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.
She is otherwise a healthy, well child.

What is the likely diagnosis?

Answer 11

Precordial catch (benign chest wall pain)
Explanation
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 12

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 12

Answer
Coronary artery aneurysms
Explanation
These findings indicate a diagnosis of Kawasaki disease (KD). Coronary artery aneurysms occur in 20–25% of untreated KD 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 13

What cardiac condition is associated with Williams syndrome?

Answer 13

Supravalvular aortic stenosis (AS)
Explanation
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 14

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 14

Venous hum
Explanation
Venous hum is caused by blood draining down collapsing jugular veins into the relatively 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 15

A 4-week-old infant presents with:

“Breathing fast” as described by 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 15

Ventricular septal defect (VSD)
Explanation
VSD is a left-to-right shunt where blood from the systemic (left) ventricle shunts to the pulmonary (right) ventricle through a defect in the ventricular septum. It is the most common congenital heart defect recognized in the 1st few months 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 1st month of life, more blood flows across the VSD, leading to heart failure.

Question 16

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 16

2° atrioventricular (AV) block, Mobitz 2
Explanation
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 17

Lithium use in pregnancy is associated with what cardiac abnormality?

Answer 17

Ebstein anomaly (EA) of the tricuspid valve
Explanation
EA is rare. It has been 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 echocardiogram with wall-to-wall heart shadow on CXR in the symptomatic newborn.

Question 18

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

Answer 18

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

Question 19

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

What is the next most likely cause of sudden death in a high school athlete?

Answer 19

Answer
Anomalous origin of the left coronary artery from the aorta
Explanation
This occurs when the left (most commonly) or right coronary arteries come off the opposite coronary cusp of the aorta 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 20

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

Answer 20

Total anomalous pulmonary venous return (TAPVR; supracardiac)
Explanation
Total anomalous pulmonary venous return (TAPVR) 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 with TAPVR present early with tachypnea, mild cyanosis, and failure to thrive. The “snowman” finding occurs when the pulmonary veins drain into the left superior vena cava (SVC) and blood flows then into the innominate vein, where it finally enters the heart through the normal right SVC.

Question 21

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

Answer 21

22q11.2 deletion syndrome (a.k.a. DiGeorge syndrome)
Explanation
22q11.2 deletion syndrome is associated with a complete interruption of the aortic arch. The FISH test (22q11 marker) is the diagnostic test for 22q11.2 deletion syndrome.

Question 22

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 22

Mobitz 1 (a.k.a. Wenckebach)
Explanation
This type of 2° atrioventricular (AV) block is primarily caused by increased vagal tone on the AV node and is generally not progressive or malignant. It rarely requires treatment

Question 23

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 on ECG
What is the most likely diagnosis?

Answer 23

Acute pericarditis
Explanation
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 24

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

Answer 24

Answer
Pulmonic stenosis (PS)
Explanation
Alagille syndrome, caused by absence of or mutation in the JAG1 gene, primarily affects the liver but also has cardiac manifestations. In addition to PS (8%), individuals with Alagille syndrome have peripheral and branch PS (67% of patients) and tetralogy of Fallot (7–16% of patients). Noonan syndrome is a genetic congenital disorder due mostly to mutations of the PTPN11 or SOS1 gene and affects many parts of the body. ~ 50–60% of children with Noonan syndrome have PS.

Question 25

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

Answer 25

Answer
Pericarditis
Explanation
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. (Remember that chest pain in children is usually noncardiac!)

Question 26

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, middiastolic murmur at the apex.
What is the most likely heart defect?

Answer 26

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

Question 27

A child presents with mitral valve prolapse with a midsystolic click and murmur heard best at the apex.

What antibiotic prophylaxis does he require before his dental cleaning?

Answer 27

None
Explanation
The guidelines changed in 2007 (reviewed and reaffirmed in 2021). 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 after the procedure
Repaired congenital heart disease with a residual lesion
Cardiac transplant recipients who develop a valvulopathy

Question 28

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 and right ventricular enlargement and right axis deviation.
What is the most likely diagnosis?

Answer 28

Ostium secundum type of atrial septal defect (ASD)
Explanation
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 and right ventricular hypertrophy are also common with long-standing disease. Differentiate the ostium secundum defect from the ostium primum defect by finding left axis deviation in the latter and right axis deviation 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 29

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

Answer 29

Egg-shaped or oval-shaped heart
Explanation
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. However, this classic CXR finding is only seen in ~ 33% of infants with complete d-TGA, and almost never seen in the newborn period

Question 30

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 mid- to 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 30

Answer
Tetralogy of Fallot (TOF)
Explanation
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—along with ventricular septal defect, overriding aorta, and right ventricular hypertrophy.

Question 31

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 occasional, simple premature ventricular contractions (PVCs).

What is the best treatment for this boy?

Answer 31

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

Question 32

What is the most common congenital heart lesion diagnosed in the 1st month of life?

Answer 32

Ventricular septal defect (VSD)
Explanation
VSD is a left-to-right shunt defect where blood from the systemic (left) ventricle shunts to the pulmonary (right) ventricle through a defect in the ventricular septum. It is the most common congenital heart defect recognized in the 1st few months of life. It 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 33

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

What is the likely diagnosis?

Answer 33

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

Question 34

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

Grade 4/6 crescendo-decrescendo systolic murmur at the left midsternal border, radiating to the right upper sternal border
Palpable thrill over precordium
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 34

Hypertrophic cardiomyopathy (HCM)
Explanation
HCM is an autosomal dominant disorder with variable expression. It is the most common cause of sudden death in the child athlete. Murmurs are usually harsh, systolic ejection murmurs heard best at the left midsternal border, radiating to the right upper sternal border. 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 is also heard at the right upper sternal border. In HCM, Valsalva and standing increase the murmur. In AS, these maneuvers decrease the murmur. The ECG is almost always abnormal, demonstrating left ventricular hypertrophy.

Question 35

What is the most common benign murmur of infancy?

Answer 35

Physiologic peripheral pulmonary stenosis (PPS)
Explanation
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 base of the heart, the axilla, and in 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 36

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

Systolic ejection murmur with a vibratory or “musical” character
The murmur is heard best at the LLSB and not in the back.
The murmur decreases markedly with positional changes that decrease venous return.
What is the most likely murmur?

Answer 36

Still’s murmur
Explanation
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 37

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, heard best 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 37

Pulmonic stenosis (PS)
Explanation
PS is the 2nd 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. Tall R waves in V1 and V2 signal right ventricular hypertrophy. If the stenosis is mild, no therapy is required. If more severe, these children may need pulmonary balloon valvuloplasty or surgical valvotomy.

Question 38

What diuretic causes hyperkalemia and, more rarely, gynecomastia?

Answer 38

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

Question 39

What is the most common aortic arch abnormality that can cause significant breathing and feeding problems in the infant?

Answer 39

Double aortic arch
Explanation
Double aortic arch (persistence of both right and left 4th 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 microdeletions on chromosome 22 (DiGeorge locus) in infants with aortic arch abnormalities.

Question 40

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 40

Patent ductus arteriosus (PDA)
Explanation
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 that commonly increases in intensity in late systole.

Question 41

A 6-year-old girl presents with:

Migratory arthritis
Fever
Elevated CRP
Arthralgia
What is the most likely diagnosis?

Answer 41

Rheumatic fever (RF)
Explanation
To make a diagnosis of RF, you must have either 2 major manifestations of the Jones criteria or 1 major and 2 minor manifestations. The patient has 1 major (arthritis) 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 42

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 42

Tricuspid atresia
Explanation
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 dextrotransposition 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 43

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

Answer 43

Complete atrioventricular (AV) canal defect
Explanation
Complete AV canal defect (a.k.a. endocardial cushion, 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.