Congenital heart disease nursing: a complete reference for students

Congenital heart disease (CHD) is the most common group of birth defects, affecting roughly 1 in 100 live births. It encompasses a broad spectrum of structural anomalies — from small holes that close on their own, to complex single-ventricle physiology that requires staged surgical reconstruction over the first few years of life. For nurses in the NICU, pediatric cardiac unit, or any unit that receives infants and children, CHD demands fluency in hemodynamic classification, recognition of decompensation, and the clinical judgment to act on subtle early signs.

This reference organizes CHD into two major categories — acyanotic (left-to-right shunt, increased pulmonary blood flow) and cyanotic (right-to-left shunt or mixing, decreased pulmonary blood flow or parallel circulation) — and covers the eight defects most likely to appear on NCLEX. It also covers prostaglandin E1 (PGE1) management, infant feeding in cardiac disease, surgical care in the cardiac intensive care unit (CICU), and more than 15 NCLEX-specific tips. For the broader neonatal context, see the neonatal nursing reference. For pulmonary hypertension that may complicate CHD, see PPHN nursing.

At a glance: congenital heart defects

Acyanotic defects: left-to-right shunts

In acyanotic CHD, blood shunts from the high-pressure left side to the low-pressure right side of the heart. This increases pulmonary blood flow. The infant is not cyanotic at baseline — oxygenated blood still reaches the systemic circulation — but the extra volume load on the right heart and pulmonary vasculature causes its own complications: pulmonary overcirculation, right heart enlargement, pulmonary hypertension, and, over time, the risk of Eisenmenger syndrome.

VSD — ventricular septal defect

VSD is the most common congenital heart defect, accounting for approximately 25–30% of all CHD. It is a hole in the interventricular septum, most commonly located in the perimembranous (membranous) portion near the aortic valve.

Hemodynamics. Oxygenated blood shunts from the left ventricle to the right ventricle with each systole. The size of the shunt (Qp:Qs ratio) determines clinical severity. Small VSDs may produce loud murmurs with minimal hemodynamic impact; large VSDs cause significant volume overload of the right ventricle and pulmonary vasculature.

Clinical features.

• Harsh, holosystolic murmur at the left lower sternal border (LLSB), 3rd–4th intercostal space — the murmur radiates across the precordium
• Infants with large VSDs: tachypnea, diaphoresis with feeds, poor weight gain, recurrent respiratory infections (all signs of congestive heart failure from volume overload)
• Systolic thrill may be palpable at LLSB

Management. Small VSDs (restrictive) often close spontaneously in the first two years of life. Large or symptomatic VSDs require closure: surgical patch repair or, for muscular VSDs, catheter-based device closure. Medical management of CHF (diuretics, ACE inhibitors, calorie-dense feeds) bridges the infant to surgery.

Key NCLEX fact: VSD is the most common CHD. The murmur is harsh and holosystolic at the LLSB — not diastolic, not continuous.

Eisenmenger risk. Untreated large VSDs allow sustained high-pressure, high-flow pulmonary blood flow. Over time (months to years) this causes irreversible pulmonary vascular remodeling. Pulmonary vascular resistance (PVR) rises until it exceeds systemic vascular resistance (SVR), at which point the shunt reverses direction — blood now flows right-to-left, producing cyanosis. This is Eisenmenger syndrome, and once established, surgical repair of the VSD is contraindicated because closing the hole would leave the right ventricle with no outlet against the now-fixed high PVR.

ASD — atrial septal defect

ASD is an opening in the interatrial septum. The most common type is the ostium secundum defect (70% of ASDs), located in the central fossa ovalis region. Ostium primum defects are located lower in the septum near the atrioventricular valves and are associated with Down syndrome.

Hemodynamics. Blood shunts from the left atrium to the right atrium. The right ventricle and pulmonary vasculature handle increased volume. Because this is an atrial-level shunt (low pressure differential), the clinical impact in childhood is usually modest.

Clinical features.

• Fixed, widely split S2 — this is the pathognomonic finding. Normally, the split of S2 widens with inspiration and narrows with expiration. In ASD, the right ventricle is perpetually volume-loaded, so its prolonged ejection time fixes the split regardless of the respiratory cycle.
• A systolic ejection murmur at the upper left sternal border (pulmonic area) from increased flow across the pulmonary valve — this is a flow murmur, not from the ASD itself
• Most children are asymptomatic; the defect is often found incidentally on a murmur workup

Late complications. Left unrepaired into adulthood:

• Paradoxical embolism: a venous clot crosses the ASD and enters the arterial circulation, causing stroke
• Atrial fibrillation from right atrial enlargement
• Pulmonary hypertension (less common than with VSD/PDA, but possible)

Management. Catheter-based closure with a septal occluder device (for secundum ASDs) or open surgical repair (for primum and large defects). Closure is recommended before school age if the defect is hemodynamically significant.

Key NCLEX fact: Fixed split S2 = ASD. This is the single most tested ASD finding on NCLEX. Do not confuse it with VSD or PDA.

PDA — patent ductus arteriosus

The ductus arteriosus is a fetal shunt connecting the pulmonary artery to the aorta, designed to bypass the uninflated fetal lungs. It normally closes within 24–72 hours of birth in response to rising arterial oxygen tension and falling prostaglandin E2 (PGE2). A PDA persists when this closure does not occur.

Risk factors. Prematurity (the ductus is more prostaglandin-sensitive and less responsive to oxygen in premature infants), maternal rubella infection in the first trimester, hypoxia at birth, and altitude.

Hemodynamics. Blood shunts from the high-pressure aorta into the lower-pressure pulmonary artery throughout the cardiac cycle — both systole and diastole — producing a continuous left-to-right shunt. This floods the pulmonary vasculature with additional blood.

Clinical features.

• Continuous “machinery” murmur heard best at the left infraclavicular region — the murmur runs through systole and diastole without interruption, peaking at S2
• Bounding peripheral pulses (wide pulse pressure from diastolic runoff into the pulmonary circuit)
• Tachycardia, tachypnea, and widened pulse pressure
• In premature infants: apnea, worsening respiratory distress, and need for increased ventilatory support

Management.

• Premature infants: indomethacin (or ibuprofen) IV — COX inhibitor that reduces prostaglandin synthesis, causing the ductus to constrict. Indomethacin is most effective in the first days of life. Contraindicated if the infant has renal failure, thrombocytopenia, or necrotizing enterocolitis.
• Term infants and older children: surgical ligation via left thoracotomy, or catheter-based coil/device occlusion.
• Conservative: fluid restriction and diuretics in infants who are not surgical candidates.

Key NCLEX fact: Continuous “machinery” murmur = PDA. The murmur is continuous through systole and diastole. Indomethacin closes the PDA by reducing prostaglandins — it does not open it.

Coarctation of the aorta

Coarctation is a discrete narrowing of the aorta, almost always at or just distal to the ductus arteriosus (juxtaductal coarctation). The narrowing obstructs systemic blood flow, causing a pressure differential between the upper body (proximal to the coarctation) and the lower body (distal to it).

Associated conditions. Turner syndrome (45,X) is strongly associated — coarctation occurs in 10–35% of females with Turner syndrome. Bicuspid aortic valve co-occurs in 50–85% of patients with coarctation.

Clinical features.

• Hypertension in the upper extremities and hypotension in the lower extremities — this pressure gradient is the defining hemodynamic finding
• Femoral pulse deficit (weak or absent femoral pulses compared to brachial) or brachial-femoral pulse lag (femoral pulse palpated after the brachial pulse)
• Blood pressure differential: measure in right arm (pre-ductal) and a lower extremity; a gradient >20 mmHg is significant
• Rib notching on chest X-ray in older children and adults — intercostal arteries enlarge as collateral vessels, eroding the undersurface of the posterior ribs (seen from the 3rd–9th ribs)
• Infants with critical coarctation: shock and metabolic acidosis when the PDA closes, because ductal flow was providing systemic perfusion distal to the obstruction

Management. Balloon angioplasty with stent placement or surgical resection with end-to-end anastomosis. Critical neonatal coarctation with ductal dependency requires PGE1 infusion to maintain patency of the ductus and preserve distal perfusion until repair.

Key NCLEX fact: Always check four-extremity blood pressures in suspected coarctation. Upper extremity HTN + lower extremity hypotension + femoral pulse deficit = coarctation until proven otherwise.

Cyanotic defects: right-to-left shunts and mixing lesions

In cyanotic CHD, deoxygenated blood bypasses the lungs and enters the systemic circulation (right-to-left shunt), or oxygenated and deoxygenated blood mix at a cardiac level, producing systemic oxygen desaturation. The infant is blue — hence the clinical term “blue baby.”

A useful mnemonic for the cyanotic defects is the 5 Ts: Tetralogy of Fallot, Transposition of the great arteries, Truncus arteriosus, Total anomalous pulmonary venous return (TAPVR), and Tricuspid atresia.

Tetralogy of Fallot (TOF)

TOF is the most common cyanotic congenital heart defect and one of the highest-yield NCLEX topics in all of pediatric cardiac nursing.

The four components:

1. Ventricular septal defect (VSD) — large, non-restrictive, perimembranous
2. Right ventricular outflow tract obstruction (RVOTO) — usually subvalvular (infundibular) pulmonary stenosis
3. Overriding aorta — the aortic root straddles the VSD, receiving blood from both ventricles
4. Right ventricular hypertrophy (RVH) — a consequence of chronic right ventricular pressure overload from the RVOTO

Hemodynamics. Pulmonary stenosis increases right ventricular pressure. Blood takes the path of least resistance through the VSD into the overriding aorta, bypassing the lungs. The degree of pulmonary stenosis determines the degree of cyanosis: mild stenosis may allow near-normal oxygen saturation at rest (“pink tet”), while severe stenosis causes profound cyanosis.

Clinical features.

• Cyanosis — present from birth or emerging over the first months of life as the right ventricular infundibulum hypertrophies
• Clubbing of fingers and toes (chronic hypoxia → periosteal proliferation)
• Boot-shaped heart on chest X-ray — upturned apex from right ventricular hypertrophy, concave main pulmonary artery segment (pulmonary stenosis), and a small pulmonary vascular shadow
• Systolic ejection murmur at the upper left sternal border (from pulmonary stenosis — not from the VSD, which is non-restrictive and generates no significant gradient)
• Polycythemia on CBC — compensatory increase in red cell mass from chronic hypoxia

Tet spells (hypercyanotic episodes). Tet spells are acute episodes of severe cyanosis and hypoxia triggered by infundibular spasm, crying, feeding, defecation, or fever. The infundibulum goes into spasm, pulmonary blood flow drops acutely, and right-to-left shunting through the VSD suddenly increases. The infant becomes profoundly cyanotic and may lose consciousness.

Tet spell management (priority order):

1. Knee-chest position (or squatting in older children) — increases SVR by kinking the femoral arteries, which raises aortic pressure above right ventricular pressure, reducing right-to-left shunting and forcing more blood through the pulmonary circuit
2. Supplemental oxygen — pulmonary vasodilator, but less important than mechanical SVR increase
3. Morphine IV or IM — reduces infundibular spasm, decreases respiratory drive and agitation
4. IV fluids — volume augments preload and improves cardiac output
5. Phenylephrine (alpha agonist) — raises SVR pharmacologically when position alone is insufficient
6. Propranolol — beta-blocker that reduces infundibular spasm; also used as oral prophylaxis between spells

Key NCLEX fact: During a tet spell, knee-chest position is the priority nursing intervention — not oxygen alone. Squatting increases SVR, which counteracts right-to-left shunting.

Surgical management. Total intracardiac repair: patch closure of the VSD and widening of the right ventricular outflow tract (infundibuloplasty ± pulmonary valvotomy or transannular patch). Typically performed between 3–6 months of age.

Transposition of the great arteries (TGA)

TGA is a cyanotic defect in which the aorta arises from the anatomic right ventricle and the pulmonary artery arises from the anatomic left ventricle — the opposite of normal. This creates two parallel, non-communicating circulatory circuits: deoxygenated blood from the body returns to the right heart and is pumped back out to the body via the aorta; oxygenated blood from the lungs returns to the left heart and is pumped back to the lungs via the pulmonary artery.

This arrangement is not compatible with life unless there is some communication between the two circuits. Most newborns with TGA survive the first hours because a PDA and/or a patent foramen ovale (PFO) allows mixing. Mixing is the only source of systemic oxygen delivery.

Clinical features.

• Profound cyanosis from birth that does not respond to supplemental oxygen — the lungs are receiving oxygenated blood; the systemic circulation is not
• “Egg on a string” chest X-ray appearance — narrow mediastinum (because the aorta and pulmonary artery are stacked front-to-back rather than side-by-side) and a rounded cardiac silhouette; the “string” is the narrow vascular pedicle
• Tachypnea without respiratory distress (no lung pathology — the lungs are fully oxygenated)
• Metabolic acidosis from systemic hypoxia

Immediate management.

1. Prostaglandin E1 (PGE1/alprostadil) IV continuous infusion — keeps the PDA patent to maintain mixing and systemic oxygen delivery. This is a life-saving bridge to definitive repair.
2. Balloon atrial septostomy (Rashkind procedure) — a balloon catheter is passed through the foramen ovale and pulled back forcefully, tearing a larger interatrial communication to improve mixing at the atrial level. Performed at the bedside in the NICU.
3. Arterial switch operation (Jatene procedure) — definitive surgical correction performed within the first 2 weeks of life, while the left ventricle is still conditioned against pulmonary pressures. The aorta and pulmonary artery are transected and switched to their correct ventricular origins; the coronary arteries are reimplanted into the new aorta.

Key NCLEX fact: In TGA, the two circulations are parallel — not in series. The only therapy that keeps the baby alive until surgery is PGE1 (to maintain ductal mixing) and potentially balloon atrial septostomy. Oxygen alone does nothing because the lungs are already receiving fully oxygenated blood.

Hypoplastic left heart syndrome (HLHS)

HLHS describes a spectrum of defects in which the left-sided structures of the heart are severely underdeveloped: the left ventricle is tiny and non-functional, the mitral valve is hypoplastic or atretic, and the ascending aorta is severely hypoplastic. The left heart cannot support systemic circulation.

Ductal dependency. The entire systemic circulation depends on the right ventricle pumping blood through the PDA (from the pulmonary artery, retrograde into the aorta) to reach the body. If the PDA closes, systemic perfusion collapses and the infant dies. PGE1 is life-saving and mandatory from birth until surgical palliation.

Oxygen management in HLHS. This is one of the most counterintuitive concepts in neonatal cardiac nursing: do not give 100% oxygen to an HLHS infant before stage 1 palliation. The right ventricle is simultaneously perfusing the lungs and (through the PDA) the body. High inspired oxygen causes pulmonary vasodilation, which steals blood flow from the systemic circuit by dramatically increasing flow to the low-resistance lungs. The target SpO2 for stage 1 HLHS physiology is 75–85% — an intentionally low target that reflects the mixing of oxygenated pulmonary venous and deoxygenated systemic venous blood in the single right ventricle.

Staged surgical palliation. There is no corrective surgery for HLHS — the left ventricle cannot be rehabilitated. Palliation redirects the right ventricle to serve as the sole pump:

1. Norwood procedure (neonate) — creates a reconstructed aorta from the main pulmonary artery and the native hypoplastic aorta; a shunt (Blalock-Thomas-Taussig or right ventricle-to-pulmonary artery Sano shunt) provides controlled pulmonary blood flow.
2. Glenn procedure (3–6 months) — the superior vena cava is connected directly to the pulmonary artery, so upper body venous return bypasses the heart and flows passively into the lungs.
3. Fontan procedure (2–4 years) — the inferior vena cava is also connected to the pulmonary artery, completing the total cavopulmonary connection. All systemic venous return now flows passively into the lungs; the right ventricle pumps only systemic arterial blood.

Key NCLEX fact: HLHS requires PGE1 immediately after birth. Target SpO2 is 75–85%, not >95%. Supplemental oxygen can be harmful before stage 1 palliation.

Truncus arteriosus

Truncus arteriosus is a rare defect in which a single great vessel (the truncus) exits both ventricles instead of the normal two separate outlets (aorta from the left ventricle, pulmonary artery from the right). The truncus then gives rise to both the aortic arch and the pulmonary arteries. A large VSD is always present, because the truncal valve overrides both ventricles.

Hemodynamics. Oxygenated and deoxygenated blood mix completely in the single great vessel, resulting in a fixed oxygen saturation that is lower than normal but higher than fully cyanotic defects. Pulmonary blood flow is typically increased (the pulmonary circuit receives the same systemic pressure), leading to early pulmonary vascular disease.

Clinical features. Mild to moderate cyanosis from mixing; signs of pulmonary overcirculation and heart failure (tachypnea, poor feeding, diaphoresis); a single semilunar valve that may be stenotic or regurgitant.

Management. Early surgical repair (within the first weeks to months of life) — the Rastelli procedure separates the pulmonary artery from the truncus, closes the VSD, and connects the right ventricle to the pulmonary artery via a conduit.

Hemodynamic classification table

Eisenmenger syndrome. When any uncorrected left-to-right shunt (VSD, ASD, PDA) allows prolonged high-pressure, high-flow pulmonary blood flow, the pulmonary vasculature undergoes irreversible remodeling. PVR rises progressively. When PVR exceeds SVR, the shunt reverses direction (now right-to-left), producing cyanosis, clubbing, and erythrocytosis. Surgical repair of the original defect is contraindicated at this stage — removing the shunt eliminates the right ventricle’s only pressure relief valve, causing acute right heart failure.

Prostaglandin E1 (PGE1/alprostadil): the bridge to surgery

PGE1 is one of the most critical medications in neonatal cardiac nursing. It maintains or restores patency of the ductus arteriosus in infants with ductal-dependent CHD — lesions in which survival depends on ductal blood flow.

Ductal-dependent lesions requiring PGE1:

• TGA — ductal mixing is the only source of systemic oxygenation
• HLHS — ductal flow from the pulmonary artery retrograde into the aorta provides systemic perfusion
• Critical coarctation of the aorta — ductal flow supplies the descending aorta distal to the coarctation
• Pulmonary atresia — ductal flow is the only source of pulmonary blood flow
• Tricuspid atresia — depending on associated anatomy, pulmonary blood flow may be ductal-dependent

Mechanism. PGE1 acts on prostaglandin receptors on the smooth muscle of the ductus arteriosus, causing vasodilation and maintaining patency. It counteracts the oxygen-mediated and prostaglandin-deficiency-driven constriction that normally closes the ductus after birth.

Administration. Continuous IV infusion via a dedicated central or umbilical venous catheter. Starting doses typically range from 0.01–0.05 mcg/kg/min, titrated to clinical response (SpO2, femoral pulse quality, perfusion).

Critical side effects — NCLEX priority:

Key NCLEX fact: The most dangerous side effect of PGE1 is apnea. Before starting a PGE1 infusion, confirm that resuscitation equipment (bag-valve-mask, intubation supplies) is immediately available. Never initiate PGE1 in a setting where you cannot manage the airway.

Nursing priorities across all CHD

Pre- and post-ductal pulse oximetry

Pre-ductal SpO2 is measured on the right hand (right radial artery is pre-ductal; it branches from the aorta before the ductus arteriosus insertion). Post-ductal SpO2 is measured on either foot. A gradient greater than 3% (pre-ductal higher than post-ductal) suggests a significant right-to-left ductal shunt — ductal-dependent systemic lesions or persistent pulmonary hypertension. Newborn critical CHD screening uses this principle: all newborns are screened with both pre- and post-ductal saturations before discharge.

Infant feeding and CHF management

Heart failure in infants manifests very differently from adult heart failure. Watch for:

• Diaphoresis with feeds — the effort of feeding is equivalent to exercise in a cardiac-compromised infant
• Tachypnea during or after feeds — respiratory rate >60 breaths per minute during feeding suggests pulmonary overcirculation or edema
• Fatigue and falling asleep before completing feeds — inadequate caloric intake leads to failure to thrive
• Poor weight gain — the hallmark of uncompensated CHD in infancy

Caloric strategies. Infants with CHD need 120–150 kcal/kg/day — 40–50% more than a healthy infant — because of increased metabolic demand and inefficient feeding. Interventions:

• High-calorie formula: 24–27 kcal/oz (standard formula is 20 kcal/oz)
• Fortified breast milk: human milk fortifier or calorie-dense supplement added to expressed breast milk
• Small, frequent feeds: 30–45 minute feeds every 2–3 hours to minimize fatigue
• Nasogastric (NG) or orogastric (OG) tube feeding overnight to ensure caloric goal is met
• Consultation with a pediatric dietitian

Oxygen saturation targets by lesion type

Oxygen targets are NOT the same for all CHD. In lesions where high oxygen causes pulmonary vasodilation that steals systemic flow (HLHS stage 1, truncus arteriosus), targeting SpO2 >95% is harmful. Know the targets:

• Most CHD (postoperative): SpO2 >95%
• HLHS before Norwood: SpO2 75–85% (intentionally low — balanced circulation)
• Single-ventricle palliation (Glenn/Fontan): SpO2 80–85% is expected and acceptable

Infection prevention and SBE prophylaxis

Certain CHD lesions carry a lifelong risk of infective endocarditis. Antibiotic prophylaxis before dental procedures (specifically procedures that cause gingival bleeding or perforate oral mucosa) is recommended by the American Heart Association for:

• Unrepaired cyanotic CHD (including palliated lesions with residual defects)
• Prosthetic cardiac valves (including surgical and transcatheter)
• Prior episode of infective endocarditis
• Repaired CHD with residual defects adjacent to a prosthetic patch or device (turbulent flow near the prosthetic material sustains endothelial damage)

Prophylaxis is NOT required for:

• Repaired ASD, VSD, or PDA with no residual defect if more than 6 months have elapsed since the repair (endothelialization of the repair site is complete)
• Bicuspid aortic valve without stenosis or regurgitation (historically recommended; current AHA guidelines removed this indication)

Standard prophylaxis: amoxicillin 2 g PO 30–60 minutes before the procedure (or ampicillin IM/IV if unable to take oral). For penicillin allergy: clindamycin, azithromycin, or clarithromycin.

Developmental monitoring and family support

Infants and children with CHD are at elevated risk for neurodevelopmental delay from chronic hypoxia, cardiopulmonary bypass exposure, and prolonged hospitalization. Nursing responsibilities include:

• Developmental screening using validated tools (ASQ-3, Bayley Scales) at each follow-up visit
• Referral to early intervention services when delays are identified
• Family education: activity restrictions by lesion (many children with repaired CHD have no restrictions; those with residual disease or single-ventricle physiology need individualized guidance), signs of decompensation (increased respiratory rate, new or worsening cyanosis, decreased activity tolerance, feeding difficulties), when to call the provider
• Emotional support for families navigating a diagnosis that requires staged surgeries and lifelong cardiology follow-up

Surgical care

Pre-operative management

• PGE1 infusion — continued until the moment of surgical repair in ductal-dependent lesions; confirm infusion is running on arrival to the operating suite
• Hemodynamic monitoring — continuous SpO2 (both pre- and post-ductal for ductal-dependent lesions), arterial line for continuous blood pressure, central venous access
• Baseline labs — CBC (hematocrit, platelet count), metabolic panel (glucose, electrolytes, lactate), coagulation studies (PT, PTT, fibrinogen)
• NPO — standard surgical NPO guidelines; clear fluids up to 2 hours before induction in most centers
• Temperature management — neonates are at high risk for hypothermia; maintain normothermia until the surgical team intentionally induces cooling for bypass

Post-operative care in the CICU

Post-cardiac surgery nursing is among the most complex in all of pediatric nursing. Key monitoring:

Hemodynamic monitoring:

• Arterial line — continuous beat-to-beat blood pressure; also used for frequent ABG sampling
• Central venous pressure (CVP) line — reflects right heart filling; guides fluid management
• Pulmonary artery catheter (selected cases) — measures pulmonary artery pressure and pulmonary capillary wedge pressure; monitors Qp:Qs (pulmonary-to-systemic flow ratio) in mixing lesions
• Near-infrared spectroscopy (NIRS) — cerebral and somatic oximetry; trends more important than absolute values; a sudden drop >20% from baseline triggers urgent assessment

Chest tubes:

• Mediastinal chest tube — drains blood and fluid from the pericardial space; watch for cardiac tamponade (Beck’s triad: hypotension, muffled heart sounds, jugular venous distension — or in infants, sudden rise in CVP + fall in cardiac output)
• Pleural chest tube — drains the pleural space if opened during surgery
• Measure output hourly — bleeding >3 mL/kg/hr sustained for 3+ hours warrants surgical re-exploration

Temporary epicardial pacing wires:

• Placed on the right atrium and/or right ventricle during surgery; exit through the skin below the sternum
• Enable pacing if the patient develops bradycardia or complete heart block post-bypass
• Handle with care: protect wire ends, use insulated gloves — bare wires are direct conduits to the myocardium

Junctional ectopic tachycardia (JET):

• The most common arrhythmia after pediatric cardiac surgery, especially after TOF repair and VSD closure
• Mechanism: thermal or mechanical trauma to the His bundle during surgery
• Heart rate typically 160–220 bpm with narrow QRS and AV dissociation (atrial rate slower than ventricular rate)
• Treatment: mild hypothermia (cooling to 35–36°C), amiodarone infusion, and atrial overdrive pacing to re-establish AV synchrony

Fluid management:

• Capillary leak after bypass causes significant fluid third-spacing in the first 24–48 hours; anticipate fluid bolus requirements
• Diuresis with furosemide begins as hemodynamics stabilize (usually post-operative day 1–2) to mobilize extravascular fluid
• Monitor urine output: >1 mL/kg/hr is acceptable; <0.5 mL/kg/hr for >2 hours warrants assessment

Discharge and home going

• Wound care: sternal incision instructions, signs of wound infection
• Medications: diuretics, digoxin (in some centers), aspirin (post-device implantation or Fontan), enalapril
• Activity: individualized by surgeon — most children with repaired simple lesions return to full activity; single-ventricle children have specific restrictions
• Dietary: continuation of high-calorie feeds until adequate weight gain is established post-operatively
• Follow-up: cardiology clinic within 2–4 weeks of discharge; outpatient echocardiography schedule
• Signs to return immediately: SpO2 below the established baseline, increased work of breathing, sternal instability or clicking, fever >38°C, significantly decreased feeding or wet diapers

NCLEX tips

1. VSD is the most common CHD. When a question asks for the most common congenital heart defect — the answer is VSD, not TOF, not ASD.

2. Fixed split S2 = ASD — not VSD, not PDA, not TOF. No other common defect produces this finding. If you see “fixed split S2” on NCLEX, the answer is ASD.

3. Continuous “machinery” murmur = PDA. The murmur is heard throughout the cardiac cycle (systole and diastole), loudest at the left infraclavicular area.

4. Holosystolic murmur at the LLSB = VSD. Distinguish from the systolic ejection murmur of TOF (upper left sternal border, from pulmonary stenosis) and the ejection murmur of ASD (flow murmur, pulmonic area, not from the ASD itself).

5. Boot-shaped heart on CXR = TOF. Right ventricular hypertrophy turns the apex upward; the concave pulmonary artery segment creates the “boot toe.”

6. “Egg on a string” CXR = TGA. The narrow mediastinum (aorta and pulmonary artery stacked rather than side-by-side) creates the string; the round cardiac silhouette is the egg.

7. Tet spell priority intervention: knee-chest position (not oxygen alone). Squatting/knee-chest position kinks the femoral arteries, raising SVR, which pushes more blood into the pulmonary circuit. Giving oxygen alone without increasing SVR is insufficient.

8. PGE1 most dangerous side effect: apnea. Before starting any PGE1 infusion, confirm that resuscitation equipment is at the bedside. This is the most common NCLEX answer when asked about PGE1 safety.

9. Indomethacin closes the PDA — it is a COX inhibitor that reduces prostaglandin synthesis, causing the ductus to constrict. It does NOT open the ductus. Do not confuse with PGE1, which keeps the ductus open.

10. Coarctation: always check four-extremity blood pressures. Upper extremity hypertension + lower extremity hypotension + absent or delayed femoral pulses = coarctation until proven otherwise.

11. Turner syndrome associations: coarctation + bicuspid aortic valve. Any question mentioning Turner syndrome (45,X) and a cardiac finding is almost certainly pointing toward coarctation or bicuspid aortic valve.

12. TGA: two parallel, non-communicating circuits. Oxygenated blood recirculates to the lungs; deoxygenated blood recirculates to the body. The infant needs mixing (PDA, ASD) to survive. PGE1 is the first intervention.

13. HLHS: target SpO2 75–85%, not >95%. High oxygen delivery before stage 1 palliation causes pulmonary vasodilation, which steals blood from the systemic circuit. This is counterintuitive but critical.

14. Eisenmenger syndrome: once established, surgery is contraindicated. Closing the original defect at this stage removes the right ventricle’s only pressure relief, causing fatal right heart failure. Signs: cyanosis, clubbing, polycythemia in a patient with a known left-to-right shunt.

15. Rubella in first trimester → PDA + pulmonary artery stenosis + cataracts (part of the TORCH sequence — Toxoplasmosis, Other, Rubella, CMV, Herpes). Rubella-associated CHD is specifically PDA, not VSD or ASD.

16. SBE prophylaxis before dental procedures: required for unrepaired/palliated cyanotic CHD, prosthetic valves, and prior endocarditis. NOT required for fully repaired ASD/VSD/PDA with no residual defect more than 6 months post-repair. For more detail, see infective endocarditis nursing.

17. Infant CHF feeding signs: diaphoresis + fatigue + poor weight gain. Sweating during feeds is the hallmark — it reflects the sympathetic response to increased cardiac work. Use high-calorie formula (24–27 kcal/oz) and small, frequent feeds.

NCLEX differentiation table

Key sources

Clinical content in this reference is drawn from the following authoritative sources:

• Allen HD, Shaddy RE, Penny DJ, et al. Moss and Adams’ Heart Disease in Infants, Children, and Adolescents. 9th ed. Wolters Kluwer, 2016.
• American Heart Association / American College of Cardiology. 2018 AHA/ACC Guideline for the Management of Adults with Congenital Heart Disease. JACC 2019;73(12):e81–e192.
• Gewillig M, Brown SC. The Fontan circulation after 45 years: update in physiology. Heart. 2016;102(14):1081–1086.
• Mahle WT, Newburger JW, Matherne GP, et al. AHA scientific statement: role of pulse oximetry in examining newborns for congenital heart disease. Circulation. 2009;120(5):447–458.
• National Heart, Lung, and Blood Institute (NHLBI). Congenital heart defects — overview and clinical summaries. Available at: https://www.nhlbi.nih.gov/
• Park MK. Park’s Pediatric Cardiology for Practitioners. 6th ed. Elsevier, 2014.
• Wilson W, Taubert KA, Gewitz M, et al. AHA guideline: prevention of infective endocarditis. Circulation. 2007;116(15):1736–1754 (updated 2021).
• NCSBN NCLEX-RN Detailed Test Plan (current edition) — cardiac content domains including hemodynamic monitoring, pediatric cardiac care.

For the broader neonatal context in which many of these defects present, see the neonatal nursing reference. For pulmonary hypertension as a complication of CHD, see PPHN nursing. For endocarditis risk in CHD patients, see infective endocarditis nursing. For heart failure management relevant to CHD adults and post-operative patients, see heart failure nursing.