Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 10-08: Tetralogy of Fallot + Key Features Download Section PDF Listen +++ +++ Essentials of Diagnosis ++ Five features are characteristic: Ventricular septal defect (VSD) Concentric right ventricular hypertrophy (RVH) Right ventricular (RV) outflow obstruction due to infundibular stenosis Septal overriding aorta in half of the patients A right-sided aortic arch in 25% Most adult patients have undergone surgical repair, usually with an RV outflow patch and VSD closure; if patch overrides the pulmonary valve, PR is common Physical examination may be deceptive after classic tetralogy repair, with severe pulmonary valve regurgitation difficult to detect Echocardiography/Doppler may underestimate significant pulmonary valve regurgitation; be wary if the RV is enlarged or enlarging Arrhythmias are common; periodic ambulatory monitoring is recommended Serious arrhythmias and sudden death may occur if the QRS complex is wide or the RV becomes quite large or both +++ General Considerations ++ If there is an associated atrial septal defect (ASD), the complex is called pentalogy of Fallot The basic lesion is a large VSD and migration of the septum above the VSD upward and under the pulmonary valve Pulmonary valve stenosis may also be present, usually due to a bicuspid pulmonary valve or RV outflow hypoplasia The aorta can be enlarged and aortic regurgitation may occur If more than 50% of the aorta overrides the ventricular septum, the anatomy is part of the double outlet RV nomenclature Two vascular abnormalities are common An inconsequential right-sided aortic arch (in 25%) Anomalous left anterior descending coronary artery from the right cusp (7–9%) + Clinical Findings Download Section PDF Listen +++ +++ Symptoms and Signs ++ Most adult patients in whom tetralogy of Fallot has been repaired are relatively asymptomatic unless right heart failure or arrhythmias occur Physical examination should check both arms for any loss of pulse from a prior shunt procedure in infancy Jugular venous pulsations (JVP) may reveal An increased a wave from poor RV compliance A c-v wave due to tricuspid regurgitation (rarely) The precordium may be active P2 may or may not be audible A right-sided gallop may be heard A residual VSD or persistent pulmonary outflow or aortic regurgitation murmur may be heard The insertion site of a prior Blalock or other shunt may create a stenotic area in the branch pulmonary artery (PA) causing a continuous murmur Pulmonary arterial stenotic bruits may best be heard on the lateral chest wall + Diagnosis Download Section PDF Listen +++ +++ Imaging Studies ++ Chest radiograph shows A classic boot-shaped heart with prominence of the RV and a concavity in the RV outflow tract An enlarged and right-sided aorta Echocardiography/Doppler Establishes the diagnosis by noting the unrestricted (large) VSD, the RV infundibular stenosis, and the enlarged aorta Provides data regarding the amount of residual pulmonary valve regurgitation if a transannular patch is present, RV and LV function, and the presence of aortic regurgitation in patients who have undergone repair Cardiac MRI and CT Can quantitate both pulmonary valve regurgitation and RV volumes Can identify whether there is either a native pulmonary arterial branch stenosis or a stenosis at a distal site of a prior arterial-to-PA shunt or other anomalies such as an ASD Electrophysiologic studies with ventricular stimulation and potential VT ablation has been suggested by some experts for all patients who have had evidence for VT, unexplained syncope, or a wide QRS complex, or who are older or are about to undergo pulmonary valve replacement +++ Diagnostic Studies ++ ECG reveals RVH and right axis deviation Right bundle branch block pattern in repaired tetralogy Ambulatory monitoring is recommended as well, especially if palpitations are felt Cardiac catheterization Pulmonary angiography documents the degree of pulmonary valve regurgitation RV angiography helps assess any postoperative outflow tract aneurysm + Treatment Download Section PDF Listen +++ +++ Surgery ++ Systemic arterial to pulmonary artery shunt for significant RV outflow obstruction Many infants undergo repair without this initial procedure Most adult patients have undergone this initial palliative repair Enables blood to reach the underperfused lung either by directly attaching one of the subclavian arteries to the PA (classic Blalock shunt) or by creating a conduit between the two (modified Blalock shunt) Other types of systemic to pulmonary shunts no longer in use A window between the right PA and the aorta (Waterston-Cooley shunt) A window between the left PA and the descending aorta (Potts shunt) Total repair generally includes a VSD patch, an enlarging RV outflow tract patch (usually), and a take-down of the arterial-pulmonary artery shunt Often the RV outflow tract patch extends through the pulmonary valve into the PA (transannular patch), and the patient is left with varying degrees of pulmonary valve regurgitation Over time, volume overload from severe pulmonary valve regurgitation becomes the major hemodynamic problem seen in adults Ventricular arrhythmias can also originate from the edge of the patch; they increase in frequency with the size of the RV Early surgical pulmonary valve replacement is favored A percutaneous approach to pulmonary valve regurgitation remains limited because the available percutaneous valve diameters are frequently too small for the size of the pulmonary annulus The Melody valve is a bovine jugular vein prosthesis with the largest size being 22 mm in diameter Percutaneous stented valves, particularly the Edwards SAPIEN XT, have been used successfully and can be used in patients with larger pulmonary root sizes + Outcome Download Section PDF Listen +++ +++ Follow-Up ++ QRS width should be measured yearly Reoperation is needed in about 10–15% of patients 20 years after initial repair, both for severe pulmonary valve regurgitation and for residual infundibular stenosis +++ Complications ++ Atrial fibrillation, reentrant atrial arrhythmias, and ventricular ectopy, especially after age 45 Left heart disease causes these arrhythmias more often than right heart disease Biventricular dysfunction is not uncommon as the patient ages +++ Prognosis ++ Most adults with stable hemodynamics can be active Most women can carry a pregnancy adequately if RV function is preserved +++ When to Refer ++ All patients should be referred to a cardiologist with expertise in adult congenital heart disease + References Download Section PDF Listen +++ + +Downing TE et al. Tetralogy of Fallot: general principles of management. Cardiol Clin. 2015 Nov;33(4):531–41. [PubMed: 26471818] + +Haas NA et al. Early outcomes of percutaneous pulmonary valve implantation using the Edwards SAPIEN XT transcatheter heart valve system. Int J Cardiol. 2018 Jan 1;250:86–91. [PubMed: 29017776] + +He F et al. Whether pulmonary valve replacement in asymptomatic patients with moderate or severe regurgitation after tetralogy of Fallot repair is appropriate: a case-control study. J Am Heart Assoc. 2019 Jan 8;8(1):e010689. [PubMed: 30587056] + +Paolino A et al. NT-proBNP as marker of ventricular dilatation and pulmonary regurgitation after surgical correction of tetralogy of Fallot: a MRI validation study. Pediatr Cardiol. 2017 Feb;38(2):324–31. [PubMed: 27872995] + +Smith CA et al. Long-term outcome of tetralogy of Fallot: a study from the Pediatric Cardiac Care Consortium. JAMA Cardiol. 2019 Jan 1;4(1):34–41. [PubMed: 30566184]