UW ped cardio cases Flashcards
(1) A 2-month-old boy is brought to the emergency department for evaluation of cyanosis. He became fussy and sweaty while taking his bottle, and his lips “turned blue” for several minutes during the feeding. The infant has had similar episodes during feeding and crying, but these resolved quickly. The patient was born at 39 weeks gestation, and his birth weight was average for gestational age. His weight gain has been slow, currently at the 5th percentile. He is fed pumped breast milk fortified with powdered formula to augment caloric intake. Temperature is 37 C (98.6 F), blood pressure is 80/50 mm Hg, pulse is 150/min, and respirations are 55/min. On examination, the infant is ill-appearing, agitated, cyanotic, and tachypneic. Cardiac auscultation reveals a grade 2/6 crescendo-decrescendo systolic ejection murmur at the left upper sternal border and a single second heart sound. The patient is placed in a knee-chest position immediately. This maneuver improves the patient’s condition predominantly by which of the following mechanisms?
INCREASED SVR
(1) If the resistance of the systemic circulation exceeds the resistance of the pulmonary circulation, the blood will shunt from the ventricles to the pulmonary artery (eg, left-to-right shunt). However, if the pulmonary vascular resistance (PVR) exceeds that of the systemic circulation, the blood will shunt from the ventricles into the aorta (eg, right-to-left shunt), resulting in cyanosis.
Increase in PVR (Choice C) shunts deoxygenated blood from the right ventricle across the VSD and into the aorta. This results in sudden cyanosis and is called a hypercyanotic, hypoxic, or “tet” spell. In this patient, the crescendo-decrescendo systolic ejection murmur represents RVOT obstruction. The single second heart sound (S2) comprises the normal aortic and the inaudible pulmonary component of the S2.
(1) Treatment of a “tet” spell begins with immediate???
Immediate knee-chest positioning, which kinks the femoral arteries, increases systemic vascular resistance (SVR,) and consequently reduces the degree of right-to-left shunting. In addition, inhaled oxygen (Choice A) stimulates pulmonary vasodilation (decreases PVR) and systemic vasoconstriction. Intravenous fluids improve right ventricle filling and pulmonary flow.
(2) A newborn is evaluated for bluish discoloration an hour after delivery. The patient was born at 37 weeks gestation via spontaneous vaginal delivery without complications. Apgar scores were 7 and 8 at 1 and 5 minutes, respectively. Birth weight was 3.4 kg (7 lb 8 oz). Temperature is 37.1 C (98.8 F), blood pressure is 72/34 mm Hg, pulse is 150/min, and respirations are 40/min. Pulse oximetry indicates an oxygen saturation of 76% on room air. On physical examination, the patient is well appearing with no respiratory distress. Cyanosis is present over the lips, trunk, and extremities. The lungs are clear to auscultation. No murmurs are heard on cardiac auscultation. Muscle tone is normal. When 100% oxygen is administered, the patient’s pulse oximetry reading remains at 76%. Which of the following is the most likely diagnosis?
TRANSPOSITION OF THE GREAT ARTERIES
In cyanotic congenital heart disease such as transposition of the great arteries and tetralogy of Fallot, oxygen administration does not significantly increase oxygenation because of anatomic right-to-left shunting.
(3) 30 y/o man + progressive exertional dyspnea and fatigue. No orthopnea or paroxysmal nocturnal dyspnea. Had Tetralogy fallot at age 3, done surgery. S1 normal; S2 single. Decrescendo diastolic murmur that increased with inspiration. Dx?
Pulmonic regurgitation
ToF repair, typically performed in early childhood, involves patch closure of the VSD and restructuring (eg, enlarging)of the narrowed RVOT. Enlarging the RVOT can disrupt the tissue on which the pulmonic valve is mounted (pulmonic valve anulus), resulting in progressive pulmonic valve insufficiency/regurgitation
(4) 5day old girl. <…> says that brachial pulses strong, femoral pulses weak. Cause?
increased left ventricular afterload
(5) A 2-hour-old boy is evaluated in the neonatal intensive care unit for cyanosis since birth. The infant was delivered vaginally by a 27-year-old primigravida at 39 weeks gestation. The mother has no significant medical history, and the pregnancy was uncomplicated. Birth weight was 4.1 kg (9 lb). Apgar scores were 7 and 8 at 1 and 5 minutes, respectively. Pulse is 140/min and respirations are 65/min. Pulse oximetry is 75% on room air. The infant is cyanotic but comfortable-appearing with no retractions. Chest auscultation reveals a normal S1, a single and loud S2, and no murmur. Femoral pulses are 2+ bilaterally. Oxygen administered by hood does not improve the cyanosis. Which of the following is the most likely cause of this infant’s cyanosis?
Transposition of great vessels.
(6) A 3-hour-old girl is evaluated in the neonatal intensive care unit for cyanosis. She was born at 38 weeks gestation by cesarean delivery for nonreassuring fetal heart tones. The mother is a 28-year-old primigravida who had an uncomplicated pregnancy. Apgar scores were 8 at both 1 and 5 minutes. The infant was initially rooming-in with her mother but was moved to the nursery shortly after delivery due to a dusky appearance. Pulse oximetry of the right hand and leg shows 72% on room air. The patient remains hypoxic after 10 minutes of breathing 100% oxygen delivered by hood. On examination, she is cyanotic and tremulous. She has low-set ears, micrognathia, and a cleft palate. Chest x-ray reveals an absent thymus. Echocardiography shows truncus arteriosus. Given the presumed diagnosis, this patient most likely has which of the following conditions?
HYPOCALCEMIA
Dx = DiGeorge syndrome
(6) CATCH abbreviation?
C - cardiac
A - anomalous face
T - thymic hypoplacia/aplasia
C - cleft palate
H - hypoparathyroidisim (hypoplastic/aplastic) -> hypocalcemia
(7) A 1-month-old boy is brought to the emergency department due to poor feeding. Over the past 2 weeks, the patient has been breathing harder and faster during feeds with associated diaphoresis and pallor. He has not had fever and has never turned blue, stopped breathing, or lost consciousness. The patient has no sick contacts. Medical history is unremarkable, and he takes no daily medications. Temperature is 36.7 C (98 F), blood pressure is 90/46 mm Hg, pulse is 124/min, and respirations are 62/min. Oxygen saturation is 95% on room air. There is no stridor. Mild retractions are present. Physical examination reveals a 4/6 holosystolic murmur at the left lower sternal border associated with a palpable thrill. The lungs have rales at both bases. The liver is palpable 3 cm below the right costal margin. Which of the following is the most likely cause of this patient’s clinical presentation?
Increased pulmonary blood flow
Dx - VSD
(7) This infant exhibits signs of heart failure and a holosystolic murmur at the left lower sternal border, characteristic findings of a ventricular septal defect (VSD).
To maintain systemic blood flow, left ventricular (LV) output increases but cannot keep up with the increased blood return, resulting in high-output cardiac failure.
Symptoms from both the high-output LV failure and pulmonary overcirculation include increased work of breathing (eg, tachypnea, retractions), tachycardia, diaphoresis, and pallor, particularly during times of exertion (eg, feeding in infants). Bilateral rales from increased extravascular transudate in the lungs and a palpable thrill due to turbulent intracardiac flow may be present. Signs of right-sided heart failure (eg, hepatomegaly) are also common
(8) A 1-day-old boy is in the neonatal intensive care unit due to congenital anomalies noted at birth. The infant was born vaginally at 36 weeks gestation to a 25-year-old woman, gravida 2 para 2, who declined prenatal testing and reported decreased fetal movement in the week preceding delivery. The infant was not latching well for the first 24 hours but has urinated and stooled. Examination shows a small face and jaw with a prominence on the back of the head. The oral mucosa is pink, but the hands and feet are mildly cyanotic. There are no skin creases on the palmar aspect of the digits. There is overlapping of the fingers bilaterally along with convexity of bilateral soles and limited hip abduction. A murmur at the left lower sternal border is heard on auscultation. Which of the following cardiovascular abnormalities is most likely present in this patient?
VSD
(8) This patient’s microcephaly, micrognathia, overlapping fingers, absent palmar creases, and rocker-bottom feet are consistent with trisomy 18 (Edwards syndrome).
Congenital heart disease occurs in more than half of affected patients, with ventricular septal defect (VSD) being the most common abnormality.
Holosystolic murmur that is best heard at the left lower sternal border.
(9) A 2-hour-old boy is admitted to the neonatal intensive care unit with severe respiratory distress. The patient was born via forceps-assisted vaginal delivery at 38 weeks gestation to a 35-year-old woman, gravida 2 para 2, whose pregnancy was complicated by poorly controlled gestational diabetes mellitus. The delivery was complicated by recurrent late decelerations and thick meconium. The patient was intubated in the delivery room due to respiratory distress. BP 58/30, pulse 158/min, RR 70/min. SpO2 90% in the right hand and 79% in the right foot on 100% oxygen. Physical examination is remarkable for meconium-stained nails and intercostal and subxiphoid retractions. Chest x-ray reveals bilateral, patchy opacities and hyperinflation consistent with meconium aspiration syndrome. Echocardiogram shows decreased right ventricular output. Which of the following is the best next step in management of this patient?
NITRIC OXIDE
(10) Newborn + spotaneous delivery 39 weeks + complicated by meconium-stain amniotic fluid. Got prenatal care, normal. At 5 min HR 120, RR 50. He is flexing his extremities, he moves and cries vigorously in response to stimulation. He has cyanosis of hands, feet, circumoral area. Mucous membranes and skin is pink. BEST NEXT STEP?
Reassurance and routine care
(10) Acrocyanosis is common in the first few days of life and is characterized by cyanosis limited to the hands, feet, and circumoral area (around the mouth but not involving the lips or mucosa), as seen in this patient. Cause?
It is due to vasomotor instability, which leads to slowing of capillary blood flow and increased oxygen extraction in peripheral tissues
(10) acrocyanosis, a benign form of peripheral cyanosis.
systemic oxygen saturation is normal in peripheral cyanosis.
(10) central cyanosis (ie, diffuse or mucosal involvement) indicates a potentially life-threatening condition.
inadequate oxygenation seen in central cyanosis
(10) Management of acrocyanosis in a healthy newborn (like this vigorous patient with age-appropriate vital signs) is parental reassurance and routine care, including universal screening for critical congenital heart disease (CHD).
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(11) An 18-hour-old infant is brought to the newborn nursery for assessment of a murmur. The patient was born full term via vaginal delivery. His mother’s prenatal course was uncomplicated. Apgar scores were 7 and 9 at 1 and 5 minutes of life, respectively. The patient has breastfed 5 times for 5 minutes each. He has had 1 thick, dark, sticky stool and 1 wet diaper. On examination, the patient has a 4/6 holosystolic murmur at the left lower sternal border. He has 2+ brachial and femoral pulses with no brachiofemoral delay. The liver edge is palpable 1 cm below the right costal margin. Echocardiography reveals a small (2-mm) defect in the muscular component of the interventricular septum with a left-to-right shunt. Which of the following is the most likely outcome of this patient’s condition?
Spontaneous resolution
Dx = VSD
(11) Small VSD - asymptomatic, loud holosystolic murmur; xray - normal. Mx = serial echo, most spontaneously close at age <2.
moderate to large VSD - respiratory distress, poor feeding, poor growth, loud holosystolic murmur;
xray - cardiomegaly, increased pulmonary markings.
Mx = diuretics, surgical closure
(12) A 1-day-old boy is brought to the emergency department due to worsening cyanosis. He was delivered at home via spontaneous vaginal delivery. The mother received no prenatal care and is unsure of the gestational age at delivery. The neonate did well after delivery and has breastfed several times. Two hours ago, he developed rapid breathing and cyanosis. On examination, the patient is hypotensive. Pulse oximetry from the right hand is 80% on room air and does not improve with 100% inspired oxygen. Physical examination shows a diffusely cyanotic infant. Cardiac examination reveals tachycardia, a regular rhythm, and no murmur. The patient is tachypneic but has normal breath sounds bilaterally. Chest x-ray is normal. Echocardiography is pending. Laboratory results are as follows
Prostaglandin E1
This 1-day-old neonate has rapid onset of hypotension, cyanosis, and hypoxia that fails to improve with 100% inspired oxygen (hyperoxia challenge). This presentation most likely reflects a ductal-dependent congenital heart defect, with sudden clinical deterioration after an initial normal period suggesting that closure of the patent ductus arteriosus (PDA) has affected blood flow.
(12) What are PDA-dependent congenital heart diseases? 5
A ductal-dependent heart defect requires that the PDA be maintained. Prostaglandin E1 is a vasodilator that prevents PDA closure, thereby maintaining pulmonary or systemic blood flow, depending on the cardiac lesion. It can be administered even after the PDA has closed because it may help reestablish duct patency (as in this patient who no longer has the classic machine-like murmur associated with PDA). Infusion can begin before a definitive diagnosis is made.
Coarctation of aorta
D-transposition of the great arteries
Hypoplastic left heart syndrome
Total anomalous pulmonary venous connection
Tricuspid atresia
(13) A 2-month-old boy is brought to the clinic due to poor feeding. He becomes diaphoretic when nursing and for the past week has fed for only 5 minutes at a time before falling asleep. The patient was born at term via spontaneous vaginal delivery. Today his weight is 30 g (1 oz) below his birth weight. Temperature is 37°C (98.6°F). Blood pressure is normal. On examination, the patient appears thin and is sleeping but easily arousable. Cardiac examination reveals tachycardia and a grade 1/6 holosystolic murmur over the left lower sternal border with a diastolic rumble over the cardiac apex. The S2 is prominent. The patient is tachypneic, but the lung fields are clear to auscultation. There is no clubbing, cyanosis, or peripheral edema. Which of the following is the most likely cause of this patient’s symptoms?
VSD
holosystolic murmur best heard at the left midsternal border is created by left-to-right shunting through the defect.
If a VSD is left unrepaired for a prolonged period (eg, ≥10 years), the pulmonary overcirculation can eventually cause irreversible pulmonary vascular remodeling and facilitate reversal of shunting to right-to-left (ie, Eisenmenger syndrome). This infant is without clubbing or cyanosis to suggest right-to-left shunting and has no evidence of Eisenmenger syndrome.
