The initial presentation of tetralogy of Fallot varies
depending on the severity of the obstruction of bloodflow to the lungs. Most patients will present in the neonatal
period with mild-to-moderate cyanosis, but typically
without respiratory distress. More uncommonly, patients
with very mild right ventricular outflow tract obstruction
at birth may be diagnosed at a couple months of age as the
obstruction worsens resulting in newly noticed cyanosis
and a louder murmur. Because patients with tetralogy of
Fallot have obstruction to pulmonary blood flow, they
will not present with signs of heart failure such as failure
to thrive. Irritability and lethargy are rarely seen in
patients with tetralogy of Fallot except in the setting of a
hypercyanotic spell. Clubbing is also highly unusual in
the modern era since newly diagnosed patients undergo
surgical repair before clubbing has time to develop.