ECG; Congenital Heart Dz; Bacterial Urti

1. A newborn African American male baby was observed at birth to be noncyanotic. The mother was known to have been infected with rubella during the pregnancy. On examination, the patient is found to have a continuous murmur that is present in both systole and diastole. A non-steroidal anti-inflammatory drug was prescribed, and on follow-up, the murmur was found to have disappeared. Which of the following is the most likely congenital heart defect?

Transposition of great arteries

Patent ductus arteriosus

Patent truncus arteriosus

Coarctation of the aorta

PATENT DUCTUS ARTERIOSUS (PDA)
A. Failure of ductus arteriosus to close; associated with congenital rubella
B. Results in left-to-right shunt between the aorta and the pulmonary artery
1. During development, the ductus arteriosus nonnally shunts blood from the
pulmonary artery to the aorta, bypassing the lungs.
C. Asymptomatic at birth with holosystolic 'machine-like' murmur; may lead to
Eisenmenger syndrome, resulting in lower extremity cyanosis
D. Treatment involves indomethacin, which decreases PGE, resulting in PDA closure
(PG£ maintains patency of the ductus arteriosus).

Explanation

PATENT DUCTUS ARTERIOSUS (PDA)
A. Failure of ductus arteriosus to close; associated with congenital rubella
B. Results in left-to-right shunt between the aorta and the pulmonary artery
1. During development, the ductus arteriosus nonnally shunts blood from the
pulmonary artery to the aorta, bypassing the lungs.
C. Asymptomatic at birth with holosystolic 'machine-like' murmur; may lead to
Eisenmenger syndrome, resulting in lower extremity cyanosis
D. Treatment involves indomethacin, which decreases PGE, resulting in PDA closure
(PG£ maintains patency of the ductus arteriosus).

2. A 21-year-old athletic Hispanic male presents to your office with the complaint of recent syncopal events. An ECG shows:

Which abnormality is present?

1st Degree AV block

2nd Degree type 2 block

Bundle Branch Block

3rd Degree block

2nd Degree type 1 block

The ECG shows a 2nd Degree type 1 block. This is indicated by the presence of progressive prolongation of the PR interval until a QRS complex is dropped. This is commonly seen in young, athletic individuals and is usually benign. However, it may progress to a higher degree block in some cases. It is important to monitor the patient closely and consider further evaluation if symptoms worsen or if there is evidence of hemodynamic instability.

Explanation

The ECG shows a 2nd Degree type 1 block. This is indicated by the presence of progressive prolongation of the PR interval until a QRS complex is dropped. This is commonly seen in young, athletic individuals and is usually benign. However, it may progress to a higher degree block in some cases. It is important to monitor the patient closely and consider further evaluation if symptoms worsen or if there is evidence of hemodynamic instability.

3.

In the above patient, which ECG would be most likely seen?

A

B

C

D

not-available-via-ai

Explanation

not-available-via-ai

4. A 15-month-old girl is brought to the pediatrician because of 2 days of fever, decreased eating, sleeplessness, and pulling on her right ear. The right tympanic membrane is red and bulging. Which of the following applies best?

Diagnosis can be made presumptively by culture of a nasopharyngeal swab for bacteria and viruses

The most likely cause is Streptococcus pneumoniae, Haemophilus influenzae, or Moraxella catarrhalis

The most likely cause is a respiratory virus such as rhinovirus, influenza virus, or respiratory syncytial virus

Diabetes mellitus is an important risk factor for this kind of infection

The presence of a red and bulging tympanic membrane, along with symptoms such as fever, decreased eating, sleeplessness, and pulling on the ear, suggests acute otitis media (AOM). The most common pathogens associated with AOM in children are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. These bacteria are commonly found in the nasopharynx and can ascend to the middle ear causing infection. Therefore, the most likely cause of the symptoms in this 15-month-old girl is one of these bacteria.

Explanation

The presence of a red and bulging tympanic membrane, along with symptoms such as fever, decreased eating, sleeplessness, and pulling on the ear, suggests acute otitis media (AOM). The most common pathogens associated with AOM in children are Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis. These bacteria are commonly found in the nasopharynx and can ascend to the middle ear causing infection. Therefore, the most likely cause of the symptoms in this 15-month-old girl is one of these bacteria.

5. A 7-year-old boy is kept home from school because he developed on the preceding day a runny nose, sneezing, puffiness under his eyes, fever, and tiredness. His mother gave him Tylenol syrup. Which of the following is NOT true?

The clinical diagnosis is rhinosinusitis

His illness is likely caused by rhinovirus or influenza virus or parainfluenza virus

He should be treated with antibiotic for probable bacterial superinfection

Swelling of epithelial lining of nasal passages and paranasal infundibula leads toobstruction of sinus cavities

The boy should not be treated with antibiotics for probable bacterial superinfection. This is because the symptoms described (runny nose, sneezing, puffiness under his eyes, fever, and tiredness) are consistent with a viral infection, such as rhinovirus, influenza virus, or parainfluenza virus. Antibiotics are not effective against viral infections and should only be used when there is a confirmed bacterial infection.

Explanation

The boy should not be treated with antibiotics for probable bacterial superinfection. This is because the symptoms described (runny nose, sneezing, puffiness under his eyes, fever, and tiredness) are consistent with a viral infection, such as rhinovirus, influenza virus, or parainfluenza virus. Antibiotics are not effective against viral infections and should only be used when there is a confirmed bacterial infection.

6. An 18-month-old African American girl is brought to the pediatrician by her mother, who reports that her child gets breathless and becomes blue around her lips and in her fingernails after crying or eating. The mother also noticed that her child often squatted while playing. Which of the following diagrams represents the most likely hemodynamics of the patient's heart?

A

B

C

D

E

for tetralogy, you need 3 of the 4 criteria

TETRALOGY OF FALLOT
A. Characterized by (1) stenosis of the right ventricular outflow tract, (2) right
ventricular hypertrophy, (3) VSD, and (4) an aorta that overrides the VSD
B. Right-to-left shunt leads to early cyanosis; degree of stenosis determines the extent of
shunting and cyanosis.
C. Patients learn to squat in response to a cyanotic spell; increased arterial resistance
decreases shunting and allows more blood to reach the lungs.
D. 'Boot-shaped' heart on x-ray

Explanation

for tetralogy, you need 3 of the 4 criteria

TETRALOGY OF FALLOT
A. Characterized by (1) stenosis of the right ventricular outflow tract, (2) right
ventricular hypertrophy, (3) VSD, and (4) an aorta that overrides the VSD
B. Right-to-left shunt leads to early cyanosis; degree of stenosis determines the extent of
shunting and cyanosis.
C. Patients learn to squat in response to a cyanotic spell; increased arterial resistance
decreases shunting and allows more blood to reach the lungs.
D. 'Boot-shaped' heart on x-ray

7. Which of the following complications would be most likely in this patient?

Paradoxical embolus

Cyanosis

Clbbing

Eisenmenger syndrome

Polycythemia

Eisenmenger syndrome is the most likely complication in this patient. Eisenmenger syndrome is a condition where a congenital heart defect causes abnormal blood flow between the heart chambers, leading to increased pressure in the lungs. This increased pressure can eventually cause the reversal of blood flow, known as a right-to-left shunt, resulting in cyanosis (bluish discoloration of the skin due to low oxygen levels). This patient's symptoms, such as cyanosis, are consistent with Eisenmenger syndrome.

Explanation

Eisenmenger syndrome is the most likely complication in this patient. Eisenmenger syndrome is a condition where a congenital heart defect causes abnormal blood flow between the heart chambers, leading to increased pressure in the lungs. This increased pressure can eventually cause the reversal of blood flow, known as a right-to-left shunt, resulting in cyanosis (bluish discoloration of the skin due to low oxygen levels). This patient's symptoms, such as cyanosis, are consistent with Eisenmenger syndrome.

8. An 11-year-old girl presents with 3 days of sore throat, painful swallowing, and sore swollen lumps under her jaw. The ER doctor finds an elevated temperature, enlarged red tonsils with white exudates, and several tender lymph nodes in the anterior cervical areas. Which applies best?

Treatment of acute pharyngitis with penicillin or other effective antibiotic is indicated to prevent acute rheumatic fever

Group A streptococci are susceptible to inhibition by bacitracin in the “A” disk on blood agar plate

Rapid antigen detection test for group A streptococcus is a more sensitive test for streptococcal pharyngitis than a throat culture.

Bacitracin can be used to distinguish Streptococcus pyogenes from other bacteria, with S. pyogenes being sensitive to bacitracin and others resistant. In this case bacitracin is used to distinguish S. pyogenes from other β-hemolytic streptococci.

Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of group A streptococcal infections.
S. pyogenes displays streptococcal group A antigen on its cell wall. S. pyogenes typically produces large zones of beta-hemolysis (the complete disruption of erythrocytes and the release of hemoglobin) when cultured on blood agar plates, and are therefore also called Group A (beta-hemolytic) Streptococcus

Explanation

Bacitracin can be used to distinguish Streptococcus pyogenes from other bacteria, with S. pyogenes being sensitive to bacitracin and others resistant. In this case bacitracin is used to distinguish S. pyogenes from other β-hemolytic streptococci.

Streptococcus pyogenes is a spherical, Gram-positive bacterium that is the cause of group A streptococcal infections.
S. pyogenes displays streptococcal group A antigen on its cell wall. S. pyogenes typically produces large zones of beta-hemolysis (the complete disruption of erythrocytes and the release of hemoglobin) when cultured on blood agar plates, and are therefore also called Group A (beta-hemolytic) Streptococcus