A 9-year-old girl is brought to the emergency department with an arrhythmia that started while she was sitting in class. Since birth she has had a disorder that predisposes her to arrhythmias, but because her parents were not present, the hospital staff was unable to determine her medical history. The staff attempts to treat the patient with an atrioventricular nodal block antiarrhythmic, which does not cure the problem and instead makes it worse. What congenital pathophysiology could this girl have had?
(A) Atrioventricular accessory tract
(B) Atrioventricular nodal re-entry
© Tetralogy of Fallot
(D) Ventricular hypertrophy
(E) Ventricular tachycardia
Ans:(A) Atrioventricular accessory tract