Management of Tetralogy of Fallot

Diagnosis and Clinical Presentation

Children with uncorrected Tetralogy of Fallot (ToF) may exhibit classic clinical signs such as squatting position, increasing cyanosis, or dyspnea with exertion, which helped identify children with ToF before modern imaging techniques became available 1

Patients with obstructive right heart lesions without severe resting obstruction (including repaired ToF) can participate in exercise testing, as indicated by the American Heart Association guidelines 1
Exercise stress echocardiography can be used to study right and left ventricular contractile reserve in ToF patients 2
Exercise capacity may be impaired in some patients with repaired ToF due to residual pulmonary regurgitation, right ventricular dysfunction, or impaired left ventricular mechanics 3

Cardiac MRI is the gold standard for assessing right ventricular volume and function in patients with ToF, as recommended by the Society for Cardiovascular Magnetic Resonance 3, 4, 5
Regular follow-up with a cardiologist with expertise in congenital heart disease is recommended, with at least annual evaluations, as advised by the American Heart Association 3, 4, 6
Echocardiography should assess for severity of pulmonary regurgitation, RV size and function, residual RVOT obstruction, tricuspid regurgitation, residual VSDs, and aortic regurgitation, as recommended by the American Society of Echocardiography and European Society of Cardiology 4, 6, 7

The American Heart Association and American College of Cardiology recommend understanding the unique hemodynamic challenges faced by patients with repaired Tetralogy of Fallot, including right ventricular dysfunction, typically due to pulmonary regurgitation, RV outflow tract obstruction, or both, and residual lesions such as RVOT obstruction, branch pulmonary artery stenosis, ventricular septal defects, or aortic regurgitation 4, 5, 8, 6
For patients with coronary spasm, the American Heart Association recommends high-dose calcium channel blockers, such as Verapamil 240-480 mg/day or Diltiazem 180-360 mg/day, as first-line treatment, with the European Heart Association suggesting the addition of long-acting nitrates if symptoms persist 9, 10, 11
Spontaneous remission occurs in about 50% of patients after 1 year of treatment for coronary spasm, according to the European Heart Journal, with the American Heart Association recommending considering tapering and discontinuing treatment 6-12 months after angina has disappeared, and a prognosis of excellent 5-year survival (89-97%) in patients with normal coronary arteries 9, 11
Athletes with controlled coronary spasm may participate in all levels of competition, as recommended by the American Heart Association 12

The American Heart Association recommends starting norepinephrine at 0.05-2 mcg/kg/min, titrated to maintain adequate blood pressure, to increase systemic vascular resistance and reduce right-to-left shunting, with a target systolic blood pressure appropriate for age 13, 4, 5
Providing supplemental oxygen at 6-8 L/min can improve oxygen saturation, according to the American Heart Association, and avoiding volume administration is crucial as it can worsen right-to-left shunting 13, 14
Based on echocardiographic findings, the American College of Cardiology suggests targeting the underlying cause, including optimizing preload, continuing vasopressor support, and considering inotropic support if evidence of RV failure 4, 5, 8

The American Heart Association advises against using beta-blockers for coronary spasm, which may theoretically worsen vasospasm, and recommends avoiding failure to optimize dosing before adding or switching medications for coronary spasm 9, 11
For refractory cases of coronary spasm, the American Heart Association recommends considering combination therapy with nitrates and calcium channel blockers from different classes, while the European Heart Journal suggests considering alpha-receptor blockers or Nicorandil, a potassium channel activator 9, 11