Persistent truncus arteriosus vs Other conotruncal defects
How to tell Persistent truncus arteriosus and Other conotruncal defects apart when a board question makes them look alike.
Persistent truncus is one common outflow trunk; other conotruncal defects have distinct outflow malalignment patterns.
Side by side
Persistent truncus arteriosus is failure of aorticopulmonary septation, leaving one arterial trunk overriding a VSD and causing early cyanosis.
Other conotruncal defects include tetralogy of Fallot, transposition, and interrupted aortic arch, often linked to neural crest or 22q11 abnormalities.
Persistent truncus arteriosus is failure of aorticopulmonary septation, leaving one arterial trunk overriding a VSD and causing early cyanosis.
Other conotruncal defects include tetralogy of Fallot, transposition, and interrupted aortic arch, often linked to neural crest or 22q11 abnormalities.
The repair move
Before naming the answer, force the stem through the separator: Persistent truncus is one common outflow trunk; other conotruncal defects have distinct outflow malalignment patterns.
Try a free question
CoreA newborn develops cyanosis on the first day of life, with poor feeding and respiratory distress. Echocardiography shows a SINGLE large arterial trunk arising from the heart, overriding a large ventricular septal defect, with the pulmonary arteries branching off this common trunk. Which condition is most likely?
Show answer and explanation
Answer: A. Persistent truncus arteriosus. Persistent truncus arteriosus is failure of aorticopulmonary septation (neural crest contribution failure), leaving a single arterial trunk that overrides a VSD. Mixed systemic and pulmonary blood causes early cyanosis with heart failure. Associated with 22q11.2 deletion (DiGeorge spectrum). Treat surgically in infancy.
Why the other choices are tempting
- B. Tetralogy of Fallot has the four features (VSD, overriding aorta, RV hypertrophy, pulmonic stenosis) but TWO separate great arteries.
- C. Transposition of the great arteries has aorta from RV and PA from LV (parallel circulations), cyanosis at birth, but not a single trunk.
- D. Tricuspid atresia has absent tricuspid valve and a hypoplastic right ventricle.
- E. Coarctation of the aorta is narrowing of the aortic isthmus, not a single trunk.
Flashcards
Tap a card to flip it.
What clue supports Persistent truncus arteriosus?
Choose Persistent truncus arteriosus when the stem gives this pattern: Persistent truncus arteriosus is failure of aorticopulmonary septation, leaving one arterial trunk overriding a VSD and causing early cyanosis.
What clue supports Other conotruncal defects?
Choose Other conotruncal defects when the stem gives this contrasting pattern: Other conotruncal defects include tetralogy of Fallot, transposition, and interrupted aortic arch, often linked to neural crest or 22q11 abnormalities.
Quick answers
What is the fastest way to tell Persistent truncus arteriosus from Other conotruncal defects?
Persistent truncus is one common outflow trunk; other conotruncal defects have distinct outflow malalignment patterns.
What is the key clue for Persistent truncus arteriosus?
Persistent truncus arteriosus is failure of aorticopulmonary septation, leaving one arterial trunk overriding a VSD and causing early cyanosis.
What is the key clue for Other conotruncal defects?
Other conotruncal defects include tetralogy of Fallot, transposition, and interrupted aortic arch, often linked to neural crest or 22q11 abnormalities.