A 12-year-old female with a history of prolonged QT syndrome and wheezing has the following exercise test and flow-volume loop data: Which of the following best describes these findings?
A) Variable intrathoracic obstruction
B) Flow limitation
C) Asthma
D) Variable extrathoracic obstruction

Question

A 12-year-old female with a history of prolonged QT syndrome and wheezing has the following exercise test and flow-volume loop data:   Which of the following best describes these findings?
A) Variable intrathoracic obstruction 
B) Flow limitation 
C) Asthma 
D) Variable extrathoracic obstruction

Quizplus · Accepted Answer

The flow-volume loop shows a variable extrathoracic obstruction with a characteristic "scooped out" appearance in the inspiratory portion of the loop, which is consistent with the presence of exercise-induced laryngeal obstruction. The prolonged QT syndrome may increase the risk for arrhythmias during exercise, which should also be evaluated and managed appropriately.

A 12-Year-Old Female with a History of Prolonged QT Syndrome