This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: C.V.S., Subject name: Medicine
The most common reentrant tachycardia associated with WPW syndrome is - 
Select and explain. 
A. Atrio ventricular nodal reentrant tachycardia, B. Atrial fibrillation, C. Atrial flutter, D. Atrio ventricular reciprocating tachycardia.
A: Atrio ventricular nodal reentrant tachycardia
Answer: A: Atrio ventricular nodal reentrant tachycardia 
Explanation: Ans. is 'a' i. e., Atrio ventricular nodal reentrant tachycardia Wolf - Parkinson - White Syndrome* The diagnosis of Wolf - Parkinson - White Syndrome is reserved for patients who have both preexcitation and tachydysrhythmia.* Ventricular pre excitation causes an earlier than normal deflection of the QRS complex called a delta wave.* Atrio ventricular nodal reentrant tachycardia (AVNRT) is the most common tachydysarhythmia in WPW syndrome patients. It accounts for 95% of the dysrhythmias seen with these patients. Orthodromic AVNRT is much more common than antidromic.