The 5 Cyanotic Heart Defects
1. Truncus arteriosus (1 vessel), 2. Transposition of great arteries (2 vessels switched), 3. Tricuspid atresia (3 leaflets absent), 4. Tetralogy of Fallot (4 defects), 5. TAPVR (5 words).
Tetralogy of Fallot (PROVe)
1. Pulmonary infundibular stenosis (determines cyanosis severity), 2. Right ventricular hypertrophy ('boot-shaped' heart), 3. Overriding aorta, 4. VSD. Squatting relieves Tet spells.
Neonatal RDS
Surfactant deficiency in prematurity (< 32 wks); diffuse 'ground-glass' reticulogranular infiltrates with air bronchograms on CXR; treat with maternal betamethasone + endotracheal surfactant.
Diaphragmatic Hernia (CDH)
Scaphoid abdomen + respiratory distress in delivery room; bowel loops in left hemithorax on CXR; NEVER bag-mask ventilate (distends stomach and collapses lung); immediate endotracheal intubation.
The 5 Cyanotic Congenital Heart Lesions (Right-to-Left Shunts)
| Defect | Embryology & Anatomy | CXR Classic Silhouette & Hemodynamics | Acute Management & Surgery |
|---|---|---|---|
| Tetralogy of Fallot (ToF) | Anterosuperior displacement of the infundibular septum; PROVe: Pulmonic stenosis, RVH, Overriding aorta, VSD | 'Boot-shaped' heart (upturned RV apex) with decreased pulmonary vascular markings; harsh systolic ejection murmur at LUSB | Tet spells: Knee-chest position / squatting (↑ SVR → reverses shunt → ↑ pulmonary flow) + O2 + Morphine; surgical repair in infancy |
| Transposition of the Great Arteries (TGA) | Failure of the aorticopulmonary septum to spiral; Aorta arises from RV, Pulmonary artery arises from LV | 'Egg-on-a-string' mediastinal silhouette on CXR; parallel circulations incompatible with life without mixing shunt (PDA, VSD, ASD) | Continuous IV Prostaglandin E1 (Alprostadil) immediately to keep PDA open ± emergent balloon atrial septostomy → Arterial switch surgery |
| Persistent Truncus Arteriosus | Failure of truncus arteriosus to divide into aorta and pulmonary artery due to lack of neural crest migration | Single large arterial trunk overrides a large membranous VSD; cardiomegaly with increased pulmonary markings; bounding pulses | Early surgical reconstruction with VSD closure and RV-to-PA conduit |
| Tricuspid Atresia | Absence of tricuspid valve; no direct communication between RA and RV; hypoplastic right ventricle | Left axis deviation on neonatal ECG (unusual in newborns who normally have right axis deviation); requires ASD and VSD for survival | IV Prostaglandin E1 to maintain ductal patency → Staged palliation (Fontan procedure) |
| Total Anomalous Pulmonary Venous Return (TAPVR) | Pulmonary veins fail to connect to left atrium; drain abnormally into systemic venous system (SVC, coronary sinus) | 'Snowman sign' / 'Figure-of-8' contour on CXR; right ventricular and atrial enlargement; mandatory ASD | Surgical anastomosis of pulmonary venous confluence directly to left atrium |
Neonatal Respiratory Emergencies: RDS vs. TTN vs. Meconium Aspiration
| Condition | Gestational Age & Predisposing Factors | Chest Radiograph Characteristics | Clinical Course & Management |
|---|---|---|---|
| Respiratory Distress Syndrome (RDS) | Premature infants (< 34 weeks), maternal diabetes, male sex, cesarean delivery without labor | Bilateral diffuse fine reticulogranular ('ground-glass') opacities with air bronchograms and low lung volumes | Antenatal maternal Betamethasone; Postnatal: Continuous positive airway pressure (CPAP) ± intratracheal exogenous surfactant |
| Transient Tachypnea of the Newborn (TTN) | Full-term infants delivered via elective Cesarean section (lack of vaginal thoracic squeeze and catecholamine surge) | Perihilar streaking, fluid in the interlobar fissures, hyperinflated lungs; prominent pulmonary vascularity | Supportive supplemental oxygen via nasal cannula; benign, self-limited resolution within 24–72 hours as lymphatics resorb fluid |
| Meconium Aspiration Syndrome (MAS) | Post-term (> 41 weeks) or small-for-gestational-age infants subjected to acute intrapartum fetal distress / hypoxia | Patchy, coarse, asymmetric infiltrates with alternating areas of hyperinflation and atelectasis; flattened diaphragms | Supportive oxygenation, mechanical ventilation; risk of air leaks (pneumothorax) and Persistent Pulmonary Hypertension of the Newborn (PPHN) |
OMM Board Correlate: Cranial Base & Suckling Dysfunction in Neonates
- Condylar Compression & CN XII: Birth canal compressive forces can impact the occipital condyles against the lateral masses of atlas (C1), compromising the hypoglossal canal (CN XII) and resulting in neonatal poor suckling, tongue dyscoordination, and latching failure.
- Condylar Decompression: Gentle suboccipital condylar decompression with bilateral index fingerpads restoring occipital condylar mobility is the primary osteopathic intervention for poor infant latch and excessive feeding fatigue.
- CN IX & CN X (Jugular Foramen): Compression of the petro-occipital suture impinges glossopharyngeal and vagal fibers, contributing to infantile colic, regurgitation, and swallowing difficulties.
Board Traps & Common Distractors
- In Congenital Diaphragmatic Hernia (CDH), bag-valve-mask ventilation is strictly CONTRAINDICATED in the resuscitation suite; forcing air down the esophagus distends the intrathoracic stomach and bowel loops, causing acute contralateral lung collapse and tension physiology. Perform immediate endotracheal intubation.
- In any newborn with a ductal-dependent cyanotic heart defect (TGA, severe Tetralogy, Coarctation), administration of 100% oxygen causes physiologic closure of the ductus arteriosus, precipitating sudden circulatory arrest. Maintain ductal patency with IV Prostaglandin E1.
- Physiologic jaundice never appears within the first 24 hours of life; jaundice in the first 24 hours is ALWAYS pathologic (hemolysis from Rh/ABO incompatibility or TORCH infection) and mandates immediate serum fractionated bilirubin workup.