Regarding concealed AV (atrioventricular) bypass tract, true statement is:
a) Retrograde VA conduction does not occur
b) Does not participate in AVRT (atrioventricular re-entrant tachycardia)
c) Ventricular fibrillation will not occur if atrial fibrillation develops
d) All of the above
e) None of the above
Answer: e) None of the above
In concealed AV bypass tract, it is the anterograde conduction which is absent, making it obscure in sinus rhythm. Retrograde conduction causes AVRT. It is well known that accessory pathway refractory period decreases when the rate increases as in atrial fibrillation and anterograde conduction may occur.