Basics
Description
- Aberrant embryonic development results in mixing of deoxygenated and oxygenated blood returning to systemic circulation by 2 mechanisms:
- Right-to-left intracardiac shunt
- Anatomic defects of the aortic root
- Subtypes: 5 T's, 2 E's, single ventricle:
- Tetralogy of Fallot (TOF):
- Ventricular septal defect (VSD)
- Right ventricular (RV) outflow obstruction
- Overriding aorta
- RV hypertrophy (RVH)
- Transposition of the great arteries (TGA):
- Aorta arises from RV and pulmonary artery from left ventricle (LV)
- Tricuspid atresia:
- No outlet from right atrium to RV
- Obligatory atrial level connection
- Truncus arteriosus:
- Single arterial trunk for systemic, pulmonic, and carotid circulations
- Total anomalous pulmonary venous return (TAPVR):
- Pulmonary veins drain into systemic venous circulation
- Supracardiac, cardiac, infracardiac, or mixed
- Ebstein anomaly of tricuspid valve:
- Abnormal and displaced tricuspid valve divides RV resulting in poor RV function
- Eisenmenger syndrome:
- Complication in longstanding acyanotic heart disease with L→R shunts
- Pulmonary vascular resistance reaches suprasystemic levels; R→L shunt
- Single ventricle physiology:
- Total mixing of systemic and venous return
Etiology
For most forms, cause is unknown �
Diagnosis
- Most common initial ED presentations of cyanotic congenital heart disease (CHD):
- Cyanosis
- CHF
- Circulatory collapse
- Physiologic stress triggers cyanosis in older patients with CHD:
- Cardiac shunt obstruction
- Pulmonary disease
- Decreased systemic vascular resistance
- Fever
- Dehydration
Signs and Symptoms
- Central cyanosis:
- Visible in lips, nail beds, mucosa
- Increases with cry or agitation
- Minimal change with 100% O2
- CHF:
- Rales, gallop, hepatomegaly, scalp edema
- Hypercyanotic spells or "Tet spells"�:
- Restless and hyperpneic then increased cyanosis then syncope
- Follows reductions in already compromised pulmonary blood flow:
- Wakening, feeding, vigorous cry, exercise
- Older child may compensate by squatting.
- Temporary reduction or absence of systolic ejection murmur during spell
History
- Family history of CHD:
- If parent or sibling: Increased risk of CHD
- If 2 relatives: Risk of CHD triples
- Prenatal history:
- Exposure to teratogens
- Abnormal fetal ultrasound
- TOF:
- Often asymptomatic at birth; symptoms develop as RV infundibulum hypertrophies
- Severe RV outflow obstruction; neonatal cyanosis (duct-dependent lesion)
- Cyanosis during crying or feeding (Tet spells) in toddlers
- Older, uncorrected patients:
- Dyspnea on exertion and growth delay
- Tricuspid atresia:
- Usually cyanotic from birth
- Feeding difficulties
- Older patients show dyspnea on exertion and easy fatigability
- Ebstein anomaly:
- Teens may present with dysrhythmias.
- TGA:
- Presents in 1st hr to days of life
- TAPVR:
- Neonatal presentation; severely ill:
- Cyanosis
- Does not improve with mechanical ventilation
- Infantile presentation; heart failure:
- If no obstruction to pulmonary venous return:
- Asymptomatic or mild cyanosis
- Frequent pneumonias
- Growth problems
- Truncus arteriosus:
- Mild cyanosis in newborn
- Heart failure in older infants
Physical Exam
- TOF:
- Loud systolic murmur left sternal border (LSB)
- Systolic thrill in 50%
- +/- Continuous murmur of PDA
- Loud, single 2nd heart sound (S2)
- RV prominence/bulge
- Older, uncorrected patients:
- Dusky, blue skin
- Clubbing of digits
- Retinal engorgement
- Tricuspid atresia:
- Tachypnea
- Regurgitant murmur from VSD at LSB
- +/- continuous PDA murmur
- Single S2
- Prominent LV impulse
- Ebstein anomaly:
- Holosystolic murmur of tricuspid regurgitation
- Many have diastolic murmur
- Gallop
- TGA:
- Single, loud S2
- Severe hypoxemia
- TAPVR:
- Neonatal; severe tachypnea and cyanosis
- Infantile; heart failure:
- Tachycardia
- Systolic ejection murmur at LSB
- Mid-diastolic murmur at lower LSB
- Gallop
- Fixed, split S2
- Hepatomegaly
- Truncus arteriosus:
- Newborn:
- Mild cyanosis
- Regurgitant systolic murmur at LSB
- Single S2
- Older infants; heart failure:
- Hyperdynamic precordium
- Bounding pulses
- Wide pulse pressure
- Loud, single S2
- Systolic ejection murmur and thrill
- Mid-diastolic murmur
Essential Workup
- Oxygen saturation
- ABG
- CBC, glucose
- Sepsis evaluation
- CXR to assess pulmonary blood flow
- EKG to assess for hypertrophy and QRS axis
- Cardiology consult and ECG
Diagnosis Tests & Interpretation
Lab
- Decreased room air oxygen saturation
- Hyperoxia test:
- ABG in room air and after several minutes 100% oxygen:
- PaO2 >150 in O2; no intracardiac shunt
- PaO2 <100 in O2; highly suspicious of cyanotic CHD
- CBC: Erythrocytosis with chronic cyanosis
Imaging
- CXR:
- Decreased pulmonary blood flow:
- TOF (enlarged RV)
- Tricuspid atresia (enlarged LV)
- Single ventricle physiology
- Increased pulmonary flow:
- Transposition of the great vessels (large RV)
- TAPVR (large RV)
- Truncus arteriosus (large LV and RV)
- Classic CXR descriptions:
- Boot-shaped heart: TOF; large and upturned RV looks like toe of boot
- Egg on a string: TGA; narrow mediastinum, great vessels anterior/posterior position
- Snowman sign: Supracardiac TAPVR; upper portion formed by pulmonary veins
Diagnostic Procedures/Surgery
EKG: �
- TOF:
- Right axis deviation (RAD)
- RVH
- TAPVR:
- RAD
- RVH and right atrial enlargement (RAE)
- Transposition of the great vessels:
- Tricuspid atresia:
- Superior axis
- LVH, RAE, LAE
- Truncus arteriosus:
- Ebstein anomaly:
- Right bundle branch block
- Often Wolff-Parkinson-White
Differential Diagnosis
- Pulmonary:
- Pneumothorax/hemothorax
- Bronchopulmonary dysplasia
- Congenital lung hypoplasia/dysplasia
- Pulmonary hemorrhage
- Pulmonary embolus
- Pulmonary HTN
- Diaphragmatic hernia
- Foreign body/anatomic obstruction
- Cardiac:
- Cyanotic CHD
- CHF
- Cardiogenic shock
- Infectious:
- Pneumonia, bronchiolitis
- Sepsis
- Neurologic:
- Seizure
- Neuromuscular disease
- Drug-induced respiratory depression
- Other:
- Polycythemia
- Methemoglobinemia
- Dehydration
- Hypoglycemia
Treatment
Initial Stabilization/Therapy
- Maintain warmth (cold ↑ O2 consumption).
- Treat hypoglycemia and acidosis.
- Maintain oxygenation.
- Establish IV access.
- Prepare for endotracheal intubation.
- High oxygen tensions promote ductal closure.
- Place air filters on all IV lines to avoid paradoxical emboli through R→L shunt.
Ed Treatment/Procedures
- Administer prostaglandin E1 (PGE1) to dilate or reopen the ductus arteriosus:
- Continuous IV infusion 0.05-0.1 μg/kg/min
- Complications include apnea, bradycardia, hypotension, and seizures:
- Generally intubate prior to transport
- Not effective for obstructed TAPVR:
- May require ECMO awaiting surgery
- Overall benefits far outweigh potential risks
- Evaluate and treat alternate causes of cyanosis:
- Septic workup and empiric antibiotics
- Fluid resuscitate (increments of 10 mL/kg)
- Maintain normoglycemia
- Patients with Tet spells:
- Provide a calming environment.
- Place child in knee-chest position.
- Supplemental O2 if not agitating to patient
- IV or IM morphine
- For severe cases not responding to above:
- IV bicarbonate to treat severe acidosis
- IV phenylephrine to ↑systemic vascular resistance and reduce R→L shunt
- IV propranolol for β-adrenergic blockade
- Cyanosis in the older patient with known CHD:
- 10-20 mL/kg NS IV if dehydration likely
- Supplemental O2 if suspicious for pulmonary diseases
- Antipyretics for fever
- Antibiotics for pneumonia/infectious process
- Circulatory collapse from CHD:
- Fluid resuscitation
- Inotropes: Dobutamine, dopamine, milrinone
- Aggressive treatment of acidosis
Medication
- Acetaminophen: 15 mg/kg PO or PR
- Ampicillin: 50 mg/kg IV
- Dobutamine: 5-20 μg/kg/min IV
- Dopamine: 5-20 μg/kg/min IV
- Gentamicin: 4 mg/kg/d IV or 2.5 mg/kg/dose
- Ibuprofen: 10 mg/kg PO (>6 mo)
- Milrinone: 0.25-1 μg/kg/min
- Morphine sulfate: 0.1 mg/kg SC, IM, or IV
- Phenylephrine: 0.5-5 μg/kg/min IV
- Propranolol: 0.1 mg/kg IV
- PGE1: 0.05-0.1 μg/kg/min
- Sodium bicarbonate: 1-2 mEq/kg IV
Follow-Up
Disposition
Admission Criteria
- All newborns with suspected CHD:
- CHD with acute worsening of cyanosis or CHF
- CHD with symptomatic pneumonia or respiratory syncytial virus
Discharge Criteria
- Determine in consult with cardiologist
- Patients who respond to minimal intervention (i.e., TOF patients treated noninvasively)
- Ensure close follow-up.
Issues for Referral
- Primary care physician to coordinate care
- Cardiologist for diagnosis, medical management, and ongoing monitoring
- Cardiothoracic evaluation for surgery
Follow-Up Recommendations
- Plan for follow-up should be determined in consult with the pediatric cardiologist.
- Clear instructions for return visits, as any physiologic stress may worsen condition.
Pearls and Pitfalls
- Visual appearance of cyanosis requires >3-5 mg/dL deoxygenated hemoglobin.
- Duct-dependent lesions:
- Present at 2-3 wk of age
- Sudden cyanosis or cardiovascular collapse
- Treat with PGE1:
- Beware apnea and hypotension
Additional Reading
- Apitz �C, Webb �GD, Redington �AN. Tetralogy of Fallot. Lancet. 2009;374:1462-1471.
- Bonow �RO, Mann �DL, Zipes �DP, et al., eds. Congenital heart disease. Braunwalds Heart Disease. 98th ed. Philadelphia, PA: Saunders Elsevier; 2012:1411-1467.
- Dolbec �K, Mick �N. Congenital heart disease. Emerg Med Clin North Am. 2011;29:811-827.
- Fleisher �GR, Ludwig �S, Bachur �RG, et al., eds. Cardiac emergencies. Textbook of Pediatric Emergency Medicine. 6th ed. Philadelphia, PA: Lippincott Williams, & Wilkins, 2010:690-701.
- Yee �L. Cardiac emergencies in the first year of life. Emerg Med Clin North Am. 2007;25:981-1008.
Codes
ICD9
- 745.2 Tetralogy of fallot
- 745.4 Ventricular septal defect
- 746.89 Other specified congenital anomalies of heart
- 747.21 Anomalies of aortic arch
- 429.3 Cardiomegaly
- 745.10 Complete transposition of great vessels
ICD10
- Q21.0 Ventricular septal defect
- Q21.3 Tetralogy of Fallot
- Q24.8 Other specified congenital malformations of heart
- Q25.4 Other congenital malformations of aorta
- I51.7 Cardiomegaly
- Q20.3 Discordant ventriculoarterial connection
SNOMED
- 12770006 cyanotic congenital heart disease (disorder)
- 86299006 Tetralogy of Fallot (disorder)
- 30288003 Ventricular septal defect (disorder)
- 253530007 right ventricular outflow tract obstruction (disorder)
- 204296002 Discordant ventriculoarterial connection
- 63934006 Overriding aorta (disorder)
- 89792004 right ventricular hypertrophy (disorder)