Tetralogy of Fallot (TOF) in Adults Differential Diagnoses

Updated: Nov 13, 2018
  • Author: Shabir Bhimji, MD, PhD; Chief Editor: Yasmine S Ali, MD, FACC, FACP, MSCI  more...
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DDx

Diagnostic Considerations

When an adult with tetralogy of Fallot (TOF) presents, a wide variation exists in their clinical signs and symptoms, primarily owing to differences in the basic anatomic morphology of the heart and the types of surgical repair performed in infancy. Moreover, the pathophysiology of this condition primarily depends on the severity of the right ventricular (RV) outflow tract obstruction (RVOTO). In turn, RVOTO determines the severity of the right-to-left shunting, which is typical.

Two key reasons for why some individuals with tetralogy of Fallot present much later in life are 1) the perimembranous ventricular septal defect (VSD) is small (whereas it is usually quite large in children) and 2) the RVOTO is mild. For those who already underwent surgery in childhood, the most common reason for later presentation is pulmonary valve regurgitation. However, other disorders that also should be considered when evaluating an adult patient with tetralogy of Fallot include the following:

  • Endocarditis

  • Cerebral embolism

  • Cardiogenic shock

  • Pulmonary atresia

  • VSD

  • Lung disorders (eg, asthma, reactive airway disease)

  • Right heart failure

Differential Diagnoses