Treatment Options
Neonates with severe disease presenting with profound cyanosis require emergent treatment with alprostadil (prostaglandin E₁) to provide adequate pulmonary blood flow r5
- Administer alprostadil at birth to maintain patent ductus. Continue infusion until the neonate is transferred to a specialized center for surgical repair
- Anticipate apnea with administration r5r17
Before surgery, hypoxic or hypercyanotic spells in neonates or infants are treated with comfort measures, oxygen, and medications
- Hypercyanotic spells in children r1r3r4
- Calm and hold infant r5
- Place the patient in knee to chest position to increase systemic vascular resistance and promote systemic venous return to right side of heart r5c74
- Ensure that the patient's clothing is not restrictive
- Administer supplemental high-flow oxygen to reduce severity of hypoxia; goal is to increase oxygen saturation to more than 90% r4c75
- Administration of oxygen does not reverse cyanosis caused by right to left intracardiac shunting
- Avoid premature attempts to obtain blood samples; may result in further agitation and worsening of hypercyanotic spell r5
- If cyanosis persists, sequentially treat as needed with the following stepwise protocol:
- Fluid bolus to improve venous return
- Morphine for analgesia and sedation as well as relaxing the outflow tract of the right ventricle and reducing ventilatory drive during hypercyanotic spells
- Propranolol to reduce right ventricular outflow tract muscle bundle spasm and improve pulmonary blood flow during acute episodes
- Prophylactic treatment may prevent occurrence of cyanotic spells in patients before surgery is performed r18
- Phenylephrine bolus to increase systemic vascular resistance, improve right ventricular outflow, and decrease right to left shunting
- Intubation and ventilation to sedate, reduce muscle spasms, and reduce oxygen consumption
- In cases of refractory hypoxia despite the aforementioned management, extracorporeal life support or surgical intervention may be necessary
Usually, medications are required only for urgent treatment of hypercyanotic spells in the setting of severe right ventricular outflow tract obstruction
Full surgical repair within the first year of life, either as primary treatment or after a palliative procedure, is the mainstay of treatment r19
- Most pediatric cardiothoracic centers prefer to perform complete repair when infants are aged 3 to 9 months owing to most of cases being physiologically balanced and thriving in the neonatal period but not requiring immediate intervention r20r21
- Neonatal intervention is indicated for symptomatic neonates presenting with severe cyanosis or hypercyanotic spells
- Primary neonatal repair is recommended if the patient weighs more than 3 kg and has well-developed pulmonary arteries r22
- Early palliative interventions may be offered for selected patients to allow deferral of a full intracardiac repair until later in infancy when surgical mortality is lower
- Neonates with low birth weight or prematurity, small or discontinuous pulmonary arteries, chromosomal anomalies, other congenital anomalies, or other comorbidities have better outcomes with a staged approach r22r23
- Traditionally involved surgical placement of a systemic to pulmonary artery shunt r24
- Transcatheter stenting of the ductus arteriosus or right ventricular outflow tract is increasingly used as alternative method to provide a source of pulmonary blood flow with a lower risk of complications than a surgical shunt r19r24r25
Drug therapy
- Prostaglandin
- Alprostadil (prostaglandin E₁) c76
- Continuous IV or intra-arterial infusion
- Alprostadil Solution for injection [Ductus Arteriosus Patency]; Neonates: 0.05 to 0.1 mcg/kg/minute continuous IV or intra-arterial (umbilical) infusion, initially. Titrate dose to target clinical response, then reduce the dose to the lowest possible dose that maintains the response. Usual dose: 0.01 to 0.1 mcg/kg/minute. Max: 0.4 mcg/kg/minute.
- Alprostadil Solution for injection [Ductus Arteriosus Patency]; Infants: 0.05 to 0.1 mcg/kg/minute continuous IV or intra-arterial (umbilical) infusion, initially. Titrate dose to target clinical response, then reduce the dose to the lowest possible dose that maintains the response. Usual dose: 0.01 to 0.1 mcg/kg/minute. Max: 0.4 mcg/kg/minute.
- Opioid
- Morphine c77
- Morphine Sulfate Solution for injection; Infants and Children: 0.05 to 0.1 mg/kg/dose IV/IM; may repeat dose as needed until desired response is achieved.
- β-Blocker c78
- Propranolol c79
- Oral
- Propranolol Hydrochloride Oral solution [Cardiovascular Disease]; Infants and Children: 1 mg/kg/day PO divided every 6 hours, initially. After 1 week, may titrate dose by 1 mg/kg/day every 24 hours as necessary. Average dose: 2.3 mg/kg/day (range: 0.8 to 5 mg/kg/day). Usual Max: 5 mg/kg/day. May further increase dose gradually if the patient becomes refractory after initial control. Max: 10 to 15 mg/kg/day. Alternatively, 4 mg/kg/day PO divided every 6 hours has been used as an initial dose.
- IV
- Propranolol Hydrochloride Solution for injection; Infants and Children: 0.15 to 0.25 mg/kg/dose (Max: 1 mg/dose) IV; may repeat once. Alternatively, 0.01 to 0.02 mg/kg/dose IV has been used, reserving higher doses for refractory spells.
- Phenylephrine c80
- Phenylephrine Hydrochloride Solution for injection; Neonates: 5 to 20 mcg/kg/dose IV once, followed by 0.1 to 5 mcg/kg/minute continuous IV infusion.
- Phenylephrine Hydrochloride Solution for injection; Infants and Children: 5 to 20 mcg/kg/dose IV once, followed by 0.1 to 5 mcg/kg/minute continuous IV infusion.
Nondrug and supportive care
Endocarditis prophylaxis r26r27r28
- Consider for dental procedures involving manipulation of gingival or periapical region of teeth or manipulation of oral mucosa r29
- Indicated for patients with the following: r30
- Unrepaired cyanotic congenital heart disease
- Repairs using prosthetic material during the first 6 months after corrective surgery
- Prosthetic valves (including transcatheter valve) or prosthetic material used for valve repair
- Residual defects at the site or adjacent to the site of prosthetic patch after corrective repair
- Previous episodes of infective endocarditis
Sports participation r31
- All patients (repaired or unrepaired) require comprehensive assessment with clinical assessment, ECG, imaging (eg, echocardiography) to assess ventricular function, and exercise testing before participation in competitive sports
- Stable patients without corrective surgery and without clinical manifestations of heart failure
- May consider low-intensity or class IA sports (eg, bowling, cricket, golf, yoga) r32
- After corrective surgery, patients without significant valvular dysfunction, outflow tract obstruction, and evidence of arrhythmia
- May consider moderate/class II to high-intensity or class III sports r32
- After corrective surgery, patients with significant ventricular dysfunction, outflow tract obstruction, or recurrent or uncontrolled arrhythmia may not participate in any competitive sports
Procedures
Complete corrective surgery r21c81
General explanation- Complete surgical repair includes:
- Separation of pulmonary and systemic circulation
- Accomplished by closure of ventricular septal defect with a polyethylene terephthalate patch c82
- Enlargement of right ventricular outflow tract to relieve right ventricle outflow obstruction; accomplished by the following:
- Resection of infundibular stenosis c83
- Relieving of pulmonary stenosis
- Valve-sparing approach is preferred when feasible to minimize occurrence of postoperative pulmonary valve incompetence; surgical strategies include intraoperative balloon pulmonary valvuloplasty, pulmonary valve reconstruction, and commissurotomy plus pulmonary cusp augmentation r23r33r34r35
- Transannular patch or patch augmentation, when needed, to provide unobstructed flow from right ventricle to pulmonary arteries
- Often includes pulmonary valve replacement, if surgery is performed in an adult r12c84
- Transatrial or transventricular approaches may be used r23
- Transatrial approach may be preferred when feasible to avoid risk of late-onset arrhythmia associated with ventriculotomy r36
Indication- Polycythemia, pulmonary hypertension, cyanosis, and clubbing
- Tricuspid, aortic, or pulmonary regurgitation
- Cardiomegaly or conduction disturbances
- Frequent paroxysmal hypercyanotic spells
Contraindications- Very low birth weight
- Small pulmonary arteries
- Multiple ventricular septal defects
- Presence of an anomalous coronary artery
Complications- Perioperative mortality for elective procedures is close to zero in experienced centers r37r38
- Immediate postoperative complications are uncommon and may include: r5
- Residual ventricular septal defect with left to right shunting
- Residual right ventricular outflow tract obstruction
- Conduction abnormalities
- Right bundle branch block is common
- Transient heart block is rare
- Premature ventricular contractions
- Right ventricular failure
- Myocardial infarction from interruption of aberrant coronary artery
- Cardiopulmonary arrest
- Postoperative bleeding
- Other: intracerebral bleeding and acute necrotizing enterocolitis
- Late postoperative complications may include:
- Right ventricular heart failure, particularly in patients requiring large transannular outflow patch repair
- Residual right ventricular outflow tract obstruction
- Pulmonary valvular insufficiency; marked regurgitation may lead to right ventricular enlargement
- Increased risk for patients requiring transannular patch repair r5
- Tricuspid regurgitation if right ventricular enlargement develops
- Conduction disturbances may develop owing to atrial and/or ventricular incisions and right-sided chamber dilation
- Persistent right bundle branch block is common
- Ventricular arrhythmia and sudden cardiac death
- Permanent heart block is rare; requires permanently implanted pacemaker
- Premature ventricular contractions; mainly a concern when associated with residual hemodynamic abnormalities
- Atrial tachycardia
- Aortic root dilation and aortic valve insufficiency
- Sudden cardiac death
Interpretation of results- Findings after repair r39
- Complete right bundle branch block is common (80%-90%) r39
- Residual pulmonary stenosis with elevated right ventricular pressure is not uncommon
- Some degree of pulmonary insufficiency is common
- Residual ventricular septal defect is not uncommon
- Patient may be asymptomatic or develop symptoms related to residual right ventricular pressure overload, volume overload, or arrhythmia r39
Palliative systemic to pulmonary shunt placement c85
General explanation- Procedure is performed before complete repair to provide stable pulmonary blood flow, reduce intracardiac shunting, and facilitate pulmonary development
- Procedures involve placement of temporary systemic to pulmonary shunt
- Blalock-Taussig shunt r22c86
- Shunt is made between subclavian artery and pulmonary artery
- Waterston shunt c87
- Shunt attaches ascending aorta to right pulmonary artery
- Potts shunt c88
- Shunt attaches descending aorta to left pulmonary artery
Indication- Patients with comorbidities for whom complete surgical repair is not immediately feasible (eg, patients with concomitant hypoplastic pulmonary arteries, coronary artery anomaly, or other major congenital anomalies)
- Patients with low birth weight or prematurity with severe right ventricular outflow tract obstruction
- Emergent treatment of refractory paroxysmal hypercyanotic spell
Complications- Postoperative pulmonary overcirculation leading to heart failure
- Chylothorax, diaphragmatic paralysis, and Horner syndrome r5
- Shunt thrombosis
- Other: intracerebral bleeding and acute necrotizing enterocolitis
- Child will eventually outgrow shunt, because more pulmonary blood flow is required to maintain adequate arterial oxygen saturation
Interpretation of results- Results in improved pulmonary blood flow and decreased hypoxia
Comorbidities
- For conditions requiring dental procedure, bowel surgery, or bladder surgery, administer subacute bacterial endocarditis prophylaxis to patients with uncorrected tetralogy of Fallot
- Other coexisting cardiac abnormalities that may require a modified surgical approach
- Persistent foramen ovale or atrial septal defect
- Pulmonary artery anomalies
- Persistent left-sided superior vena cava to coronary sinus anomaly
- Additional ventricular septal defects
- Coronary artery anomalies
Special populations
- Pregnant patients
- Pregnancy is not advisable for patients with uncorrected tetralogy of Fallot without evaluation and risk assessment by a cardiologist
- Pregnancy is generally well tolerated in females with repaired tetralogy of Fallot if significant hemodynamic abnormalities are not present before pregnancy r40
- Offer fetal echocardiography, given higher risk of congenital heart disease r10
- Consider testing for 22q11.2 microdeletion, given higher risk for offspring born to mothers with conotruncal defects, when maternal status is unknown r41